Building Construction – Process, components and materials

Building Construction - Process, components and materials

In this post we will study about building construction step by step process and  building components,

Building Construction - Process, components and materials

BUILDING CONSTRUCTION PROCESS

Building a construction step involved in any type of construction is not an easy task perhaps it requires lots of afford and investment although for building construction requires lots of time and it is tedious work yet its result is a permanent asset for us therefore care should be taken in building construction process before planning building construction projects must consider important aspects like the purpose of construction, utility, financial proficiency the demand for work, etc.

Construction of residential building required following paperwork before the start of actual construction.

These steps are of pre-construction phase➱

➱To acquire lend or plot.
➱Preparation of drawings as per requirements of consumers.
➱Estimation of material cost, labor cost and contingencies.
➱Approval of drawings and estimates from client.
➱Approval of drawings from City Development Authority.
➱Start of construction work either through contractor or laborer hired on daily basis.
➱Marking of plot boundaries.
➱Cleaning of plot.
➱Preparation of site layout as per drawing.

 To acquire lend or plot➱ 

➱It is the most important step in building construction.
➱Search for the location for the building which is best suited for building construction purposes.
➱Be careful while selecting land which has all the desired facilities available nearby and should be free from all land related issues.
➱It is suggested that do prior data collection before buying land or plot either by doing research online or seek help from real estate agents or concerned persons regarding the effective cost of the same.

 To seek technical help➱

 After selection proper land for Construction take the help of a Well known architect to make available building designs and drawing and take his/her Suggestion.

An architect will prepare the plan as per  requirement of building ,number of flats shops, According to your requirements and budget.

Then the Architect will meet and consult with An Engineer to get the details of the reinforcements and other materials to be used.How deep the foundation is going to be, width of pillar etc.

Preparing estimate and budget➱

The construction of a building Consumes a big amount of material and money. after, planning and structural detailing completed these details are transferred to the building estimator.

The building estimator will estimate the material quantity quantity of different items of work, and prepare an abstract sheet that shows the cost of building construction. if financial resources are limited we need to seek pre-approval for loans in advance or else you may end up in a cash crunch situation.

Permission from authorities➱

This is important work to do after the project is ready to be executed for that we have to take permission from the local municipal body before you could go for the construction.

Following are the list of document project required before applying for permission this document may differ from state, to state but some are essential for every building construction work.

➱Land survey:➮ survey of the land has to be carried out with the help of authorized land surveyor.
➱Soil test report of the land.
➱Land documents.
➱Architecture / elevation / sectional drawings.
➱Structural report.
➱Architect certificate of undertaking on record and certificate of the undertaking of civil engineer on record.

Approach a builder➱ 

A builder or contractor for construction must be chosen carefully because it is a mature for securing building construction quality and timely construction of work.

Pre-investigation must be done about the builder before handing work in the contract document, all the work related details must be clearly stated.

The Layouts and works details along with methods of payments time, cost and scale should be covered,

All The terms and conditions of contract should be check deeply before finalizing the deal of contract.

You must Read The Details about Pile load test click here

Building construction steps 

During building construction steps:➯
➱Site preparation or leveling work.
➱Excavation and PPC.
➱Foundation.
➱Plinth beam or slab.
➱Superstructure column.
➱Brick masonry work.
➱The lintel over door window gaps.
➱Floor slab or roof structure.
➱Door window framing and fixations.
➱Electrical and plumbing.
➱Exterior finishing.
➱Terrace and roof finishing.
➱Internal finishes.
➱Woodwork and fixture fittings.

 Site preparation or leveling➱

The construction site must be cleaned before the work is executed. this work involves the removal of roots of trees, debris and leveling ground area,

Earth work ➱

Generally excavation is carried out for the construction of wall foundations excavation should be carried out as per the drawings defined lengths and widths. after excavation, layout the foundation and back fill the remaining excavated area around foundation with soil.

In Residential buildings the floor levels is kept higher than the natural ground levels, Soil will be filled up to floor l levels and compacted,

Building Construction - Process, components and materials
Building Construction - Process, components and materials

Excavation and PCC➱ 

Excavation of foundation of building will be done with help of machines as per dimensions and measurements available in the drawing.

After Excavation, The Excavated area will leveled as per requirement and PCC (Plain Cement Concrete) Layer will be Laid Before Fixing the Reinforcements,

Foundation➱

The Base of the building is supported in the Lower most part of the building which is “foundation”.And the Foundation is directly connected with The earth soil. a building is load transferred from the superstructure to the soil and needs to be extremely strong to handle the load.
When the PCC layer is laid , The reinforcement work for foundation is started, After reinforcement is fixed , the bottom level must be checked before concreting, and The Gap between the foundation will be filled with earth soil.

Concrete work in foundation➱

It is too much necessary to check the levels of foundation prior to concrete. level the foundation base to same level now pour the concrete as per drawing specifications. Normally the concrete of ratio 1 : 4 : 8 is used for foundation, sometimes it is even Used the ratio of  1:5:10 or 1 : 6 : 20.

Here 1 : 4 : 8 means,

1 Part cement per cubic
4 Parts of sand per cubic
8 Parts of coarse aggregates,

Depth of foundation is generally 9″ to 18″ and in the maximum cases it is taken as 12″. The foundation width is equals to the depth of foundation.

Damp-proof course (D.P.C)➱ 

To protect walls from moisture, a layer of damp proof course material is laid down at floor level. i inch thick concrete layer is used. material of damp-proof course layer consists of concrete ratio 1 : 1.5 : 3 with a mixture of waterproof material 1 kilogram per bag.

Plinth beam and slab:➮

After the foundation work is done ground beam form-work preparation is started and poured with concrete.over the plinth beam, masonry work is started.

Superstructure -column:➮

The superstructure is the portion above the plinth level of the building the main component of the superstructure is a column and beam.

Brick masonry work➱ 

After Column and beam frame work is complete, Masonry works will be started with defferent materials like bricks, concrete ,blocks fly ash bricks etc. As per building drawing.

➱Masonry work is done using a cement mortar mix.
➱It is a mixture of cement and sand.

➱Masonry work is carried out with cement mortar.
➱Cement mortar is a mixture of cement and sand.
➱Ratio of cement mortar varies from 1 : 4 to 1 : 6 here 1 : 6 mean one part cement and 6 part of sand.
➱Dampen about 25 bricks with a hose pipe and clean away all loose dirt from the top of footing and moisten about a meter of surface at one end of the foundation with the hose pipe.
➱Throw a Matar line just behind the threaded level line and lay bricks on the mortar bed.
➱Make sure bricks exactly follow the threaded horizontal level line.

The lintel / door window gaps➱

➱The lintel is constructed on the door and window to support the masonry work over it . after this further masonry work is done.
➱Masonry work of buildings is carried out in one go till roof.
➱Openings for windows and doors are left during masonry Works.
➱Reinforced cement concrete beams are laid down on the top of openings so those loads of structure above openings not directly come on to the door frames.

Roofing➱ 

Roof slab of building is poured after completion of masonry Works nowadays roofing is of reinforced cement concrete slab.

Slab thickness and reinforcement details should be according to approved drawings.

Floor slab or roof structure➱ 

Then the form-work is started to construct slab resting on the column and beam. over slab form-work, slab reinforcement is placed as per slab detailed drawing.

Door window framing and fixations➱ 

After that door window frames are fixed at their specified position given in drawing.

Doors and windows➱

Traditionally, doors and windows of woods are used but steel and aluminum is also not a bad choice.

In case of wooden doors and windows, frames are fixed in walls during masonry work. panels are then fixed with hinges after plaster work.

Electrical and plumbing➱ 

Electrical and plumbings are fixed in the walls and slabs in such a way that they are concealed and not visible. after the finishing work is done. the point and pipe and left out such that later they can be finished with the electric fitting and plumbing fixtures.

Exterior finishing➱ 

Once this work is completed external plastering and finishing work is started waterproofing is also done to prevent rising dampness in the wall external cladding can also be done to enhance the elevation of the house.

Plastering and pointing:➱ 

Form-work will be  removed only after 14 days of casting of slab After removing Form work plaster work will be started, mortar for plaster work is normally of 1:3 or 1:4 to be used, thickness of plaster layers should not be greater than 0.75 inch cure the surface about 7 days so that plaster gain proper strength.

Terrace and roof finishing➱ 

On top of the slab waterproofing is done to prevent any leakage in the slab. generally, terrazzo tiling is done to prevent the slab from a weathering effect.

Internal finishing➱ 

Internal walls are plaster with smooth finish and flooring is done with tiles later on the walls are painted or textured.

Woodwork and fixture fittings➱ 

After completing the above work the furniture work will be started. side by side electrical fitting, switchboard, and plumbing fittings are complete in the bathrooms and kitchen areas too.

The final and the last process of building construction is interior decoration work. Proper furnishing and fabric is used to complete the building construction.  

Services➱ 

There different types of services which provide are as following-

➱These are electricity supply, gas supply, water supply, sanitary etc Conduit’s for electric supply are fixed in walls before plastering.

➱Similarly water supply and sanitary lines are also laid before pouring of building floor note that gas lines are not fixed in walls or slabs.

➱Gas line remains open in air.

Structural components of building and their standard dimensions➱ 

The structural components or essential elements of any building. without this structural building not able to stand and sustain its position on the ground. this components systems provide strength, stability, support and durability guarantee in structural component systems.

What is High performance concrete click to know

Following his list of building components➱ 

➮Foundation
➮Plingth
➮Earth filling
➮DPC(damp-proof course)
➮Flooring
➮Walls
➮RCC column
➮Sill level
➮Lintel
➮Ceiling
➮Chhajjas
➮RCC beam
➮Roof or slab
➮Doors
➮Windows
➮Parapet walls
➮Waterproofing on terrace
➮Coping

Building Construction - Process, components and materials

Structural components of building➱ 

Foundation➯ 

A foundation is the lowest part of building structure rested on soil below ground level. all loads of building transferred to foundation through beam and column arrangement. its main function is to distribute the load evenly and safely to the ground.

In frame structure, footings are generally used as foundation to support structural load of building.

Building Construction - Process, components and materials

Following our various types of foundations and footings used in construction: 

Shallow foundation➯ 

➮Individual footing or isolated footing
➮Combined footing
➮Strip foundation
➮Raft or mat foundation

Deep foundation➱ 

➮Pile foundation
➮Drilled shafts or caissons

Standard dimensions:➱ 

Foundation size depth totally depends on the structural and site ground condition so there are no standard dimension commendations for it.

But for small structural like rowhouses depth of foundation should be at least 1.5 m from ground level.

Plinth level➱ 

Plinth level or plinth is the offset created between ground level and superstructure of the ding. it is made by constructing a brick wall from ground level to the ring level of the building.

Its main function is to prevent the entry of moisture from the surface to the building superstructure.

Standard dimensions➱

Plinth height of any building must be at least 45 centimetres from the ground level.

What is Standard Proctor compaction test of soil 

Earth filling➱ 

An earth filling or soil filling is done between the plinth wall. it is essential to fill the open space left between the ground level to the plinth level earth filling must be very well compacted. so that the flooring gets sufficient hard surface base.

Standard dimensions➱ 

Earth must be filled to the top of the plinth level different materials can utilize as Earth fill like soil, coarse aggregate, waste materials brickbat etc.

DPC(Damp-proof course)➱ 

DPC is a lighter of waterproofing materials such as asphalt or waterproof cement at the plinth level the superstructure walls are constructed above the DPC layer so that no dampness rises from the ground surface into walls.

In sort, DPC present the rise of water to superstructure if dampness rises in the wall of the superstore it reduces the strength of the walls and creates unhealthy living conditions. also it created defects in paint and plaster and ultimately increase maintenance cost.

In the case of plinth beams are provided above ground level DPC is not required because plinth beam itself performs as a DPC layer to restrict the entry of dampness.

Building Construction - Process, components and materials

Standard dimensions➱ 

generally DPC is late on brick masonry construction up to the plinth level so the width of DPC is the same as the width of the brick wall and thickness may vary from 2.5 centimetres to 5 centimetres.

Flooring➱ 

Flooring is an important component of the home it is one which provided an attractive and pleasant look to the house flooring is made by laying tile on it.

There are different designs and materials are available to make flooring.

➮Timber flooring
➮Laminated flooring
➮Vinyl flooring
➮Porcelain or ceramic tile flooring
➮Natural stone flooring marble granite etc.

Standard dimensions➱ 

Flooring is provided above earth filling with base made of cement concrete 1 : 2 : for flooring material should have sufficient thickness and strength.

Walls➱ 

Walls are the vertical component in any structure it can be constructed using stones, bricks ,concrete blocks etc the different types of bonds are used for constructing walls .bricks walls are essential to enclose the inside area and protect against wind, sunshine, rain, etc. doors and windows are provided in the walls for ventilation and access to the building.

Standard dimensions➱

walls may be made single brick walls or double brick walls the single brick wall has a thickness of 100 millimetres in the double brick wall has a thickness of 230 millimetres.

RCC column➱ 

Columns are vertical members constructed to support any structural frame load coming from the slab, beam transferred to column and column transfer a load to the footing safely.

Building structure may have two types of columns architectural columns and structural columns architectural columns primly used to increase the aesthetic appearance of building while a structural column takes the load coming from the slab above and transfers safely to the foundation.

Standard dimensions➱ 

column may have various sizes as per the structural load requirements but for minimum dimension for any structural column is restricted to 9 X 9 or 225 mm X 225 mm.

Building Construction - Process, components and materials

Sill level➱ 

It is the base point of any window in the house or it is a level where windows are placed. sill level is very important to ensure evenness in all window level sill is a height which is ensuring that the proper amount of light enters in the house it also provides easy to habitat to look outside through the window without any discomfort dotted provides a solid base for window installment.

Standard dimensions➱

Sill level of any house should be around 3 feet or 900 millimetres.

Building Construction - Process, components and materials

Lintel➱ 

Lintels are constructed from reinforced cement concrete it is provided above the wall openings like doors, windows etc. the lintel actually takes the load coming on window and door openings.

In sort, lintel safeguard the door and window from excess load coming from above in residential building lintel can be constructed from concrete or brick masonry,

Standard dimension➱ 

Generally, the lintel width is the same as the width of wall and thickness between 4 inch to 6 inch.

Ceiling➱ 

Ceiling is not a separate part but is a bottom face of any slab ceiling is most important part of any room because it can be decorated to increase aesthetic appearance POP(Plaster of Paris) is a material used for making false ceilings. it is a location where we can hang decorative items. fan etc to increase architecture view of room.

Standard dimension➱ 

Ceiling height is kept 9′ 6″ to 10′ 6″ it can be more or less as per requirement.

Chhajjas➱

Chhajjas is also called as weather shed this is a structure which is constructed above window projected outside from window face the main function of weather shed to restrict the direct entry of rainwater and sunlight hatches are constructed from reinforced cement concrete.

Standard dimensions➱ 

The length of chhajjas = width of window + 0.15 M bearing on both side

Width of chhajjas = 0.45 M to 0.60 m

RCC beam

RCC beam is important component in any frame structure beam is horizontal member which connect column on both side. it main function is to take load from upper structure and transfer it to column. generally column to beam connection is called direct support while the beam to beam connection is called indirect support in most of cases the beam supported by two columns and the most rarely used is the cantilever beam.

Standard dimension➱ 

Minimum Beam dimension is 9″X 9″

Building Construction - Process, components and materials

Roof or RCC slab➱ 

Roof is an Important and essential  component for any building structure which provides protection against environmental factors such as Sun, wind and rain.normally all roof rests on sidewalls and required anchoring so that wind and another mechanical  impact cannot destroy it. roof may have different shapes but flat and sloped roofs are more popular typically most of roofs are constructed from RCC, stone slab,tiles etc.

Standard dimension➱ 

Generally RCC slab thickness can have minimum dimension 4″ to 6″ as per requirement.

Doors➱ 

Doors are the main entry and exit point of any house without doors there will be no security in house they are one which separates the one room from others doors have locked key facility, so we can lock the house by locking the door and go out freely they are made of strong material like steel, wood, iron ,therefore, they are not easily breakable.

There are different types of doors used in house.
➮Hinged doors
➮Dutch doors
➮Roller doors
➮Bi-fold doors and many more these are discussed below

Standard dimension➱

Main door of the drawing-room, bedroom, kitchen may have a width up to 2’6″ to 3′ and other rooms like bath, W / C is 2′ to 3′ height of doors is almost 7′ every time or up to lintel level.

Windows➱ 

Windows are one of an essential component of any house or building it is one that allows fresh air and light to enter into the house without window house becomes darkroom or jail.

Windows are provided at sill level and their height extended up to lintel level there are various types of windows used in house like

➮Single hung windows
➮Arched windows
➮Awning windows
➮Bay windows
➮Bow windows
➮Casement windows and many more are discussed below

Standard dimension➱ 

Window opening width may change depending as per requirement but its height generally kept 1.4 m From sill level or up to the bottom of the lintel.

Parapet walls➱ 

It’s a Low height wall built along the edge of the roof, terrace, walkway, balcony etc. it is generally constructed with single brick wall.It can be constructed using RCC, Steel, aluminium, glass etc.

Standard dimensions➱ 

Parapet wall height is 3 feet-0.9 m

Building Construction - Process, components and materials

Waterproofing on terrace➱ 

Damp proof course is the protective layer to restrict the movement of moisture water through roof slab. for DPC on roof flexible materials are used which provide a lesser number of joints like mastic, asphalt, Bitumen felts, plastic sheets etc.

Building Construction - Process, components and materials

Copping➱ 

Coping is structure which is constructed on top of boundary walls and parapet wall etc to protect rain water directly store on brick masonry wall.

The main function of coping is to drain off rainwater during the rainy season end improves the aesthetics of the structure/wall.

Building Construction - Process, components and materials

The standard room size and location in residential building➱

What are the standard room size and location in residential buildings in this video you come to know about the various standard dimensions of different elements of residential houses.

Area limitations➱ 

The limitation of area and height of the buildings of different types of construction and occupancy is achieved by satisfying floor area ratio (FAR). FAR is taking into account the following aspect.

➮Occupancy class
➮Type of construction
➮Width of the street fronting the building and the traffic load
➮The density and locality where the building is proposed
➮Parking facilities
➮Local firefighting facilities
➮Water supply and drainage facilities

Floor area ratio(far) = total cover area of all floors / plot area 

The floor area ratio is generally in between 1.0 to 2.0 depends on the type of construction.

For example, if a plot measures 15 m X  20 m and building bay- laws stipulates permissible FAR as 2.0 , then the maximum built-up area which can be put on the plot is 600 square meters. if the area covered at ground floor is 150 square meters, the total number of floors that can be constructed is (600/150)= 4,

Height of the building➱ 

The height and number of the story for a building are related to FAR and the provisions of open spaces are already explained earlier dot where the building height is not covered by FAR, the maximum height should be limited to the width of the street as follows,➮

➱The maximum height of the building shall not exceed two times the width of road abutting plus the front open space.

➱If a building abuts on two or more streets of different widths, the building shall be deemed to face upon the street that has the greater width and the building height shall be regulated by the width of that street and may be continued to this height to a depth of 24 m long the narrower street subject to the conformity of open spaces.

➱In the vicinity of aerodromes, the maximum height fixed in consultation with civil aviation authorities.

 Appurtenances is like a water tank on the roof ventilating and air-conditioning appliances, lift room, chimneys and parapet walls not exceeding 1.2 m height are not included in the height of the building.

Standard room size and location in residential building➱ 

The minimum Room size and location for different types of room:➮


➱Bed room, Living room, Drawing room, Dining room, Study room.

Minimum area: 9.5 sqm 

standard living room size 9 feet x 10 feet.

Minimum size of side: 

1- For single room the Minimum width should be 2.4 meter.
2-Where there are two rooms one of these shall not be less than 9.5 square M and others not less than 7.5 square m with a minimum width of 2.1 m.

The height of room: the of all room for human habitation shall not be less than 2.75 m

Other requirement: For air conditioning room height should not less than 2.4 m.

The recommended standard room size and location for the living room of various sizes are as below-



Size Dimension in meter + (Area) Dimension in Feet + (Area)
Large 6.71 X 8.53(57.24) 22 28(616)
Medium 4.88 6.01(29.33) 16 20(320)
Small  3.66 5.49(20) 12 18(216)
Very Small 3.05 3.66(11.16) 10 12(120)



Kitchen➱ 

Minimum Area: 5 sqm.

Minimum size of side: the width of the room should not be less than 1.8 meter and where is a separate store, the area of the kitchen may be reduced to 4.5 square meter, a kitchen that is intended to use as dining also shall have a floor area of not less than 7.5 sqm with minimum width 2.1 m.

The height of room: the kitchen height shall not less than 2.75 square m.

The recommended standard room size and location for the kitchen of various sizes are as below

Size Dimension in meter + (Area) Dimension in Feet + (Area)
Large 3.65 6.09(22.23) 12 20(240)
Medium 3.05 4.87(14.85) 10 16(160)
Small  3.05 2.44(6.10) 10 08(80)
Very Small 2.13 2.70(5.85) 07 09(63)

What is Consistency test of Cement click to know

Bathroom in water closet➱ 

Minimum area: 1.8 square meter (bathroom) 1.1 square meter (WC)

Minimum size of side: if bath in water closet are combined its floor area shall not be less than 2.8 square meter with minimum side width of 1.2 m.

The height of the room: shall not less than 2 M.

Other requirement 

It should be located such that at least one of its walls open to the external wall.

It should not be directly over or under any other room than another latrine washing place bath or Terrace in case of multi-storied buildings unless the floor is watertight.

it should have a platform or seat of watertight non absorbent materials.

it should be provided with the impervious floor sloping towards the drain with a suitable grade and not towards veranda or any other room.

The recommended dimensions of common bathroom of different sizes are as below: 

Size Dimension in meter + (Area) Dimension in Feet + (Area)
Large 2.13 3.66(7.8) 12(84)
Medium 1.83 3.05(5.6) 10(60)
Small  1.52 2.75(4.20) 9(45)
Very Small 1.06 1.98(2.04) 3.5 6.5(22.75)

Storeroom➱ 

Minimum area: the minimum area of storerooms should not be less than 3 sqm.

The height of store room: The store room’s height should not be less than 2.2 meter.

The recommended standard dimensions off storeroom of various sizes are as below:- 


Size Dimension in meter + (Area) Dimension in Feet + (Area)
Large 3.65 4.2615.55) 12 14(168)
Medium 2.44 3.05(7.42) 10(80)
Small  1.52 1.83(2.80) 6(30)
Very Small

Garage➱

Minimum area: The minimum area of garage should not be less than 12.5 square Meter.

The height of room: The garage should not be less than 2.4 Meter.

Staircase➱ 

Minimum size of side: The Minimum standard width of the stair is  taken 1 Meter.

The height of stair: The Minimum Standard clear Headroom’s height  shall be 2.2 meter.

Other requirement: 

➯The minimum width of tread without nosing shall be 250 millimetres for residential buildings.
➯The maximum height of rising shall be 190 millimeters for residential buildings.

Plinth height➱ 

The height of the plinth shall not be less than 450 millimetres from the surrounding ground level. a height of 600 millimetres is the best from drainage or other considerations.

Parapet wall➱ 

Parapet walls and handrails provided on the edges of roof terraces, balcony, veranda, etc shall be not less than 1.05 m and not more than 1.20 m in height from the finished floor level.

Boundary Wall➱

The requirements for the boundary wall are as following-

Except with special permission of the authority, the maximum height of the compound wall shall be 1.5 m above the center line of the front street. Compound wall height up to 2.4 meter height may be allowed if the top 0.9 meter is of an open type construction of a design should be approved by the concerned authority.

Minimum ceiling height standards for residential house➱ 

However, if there is no rule to follow contractors and development both public and private sectors tend to reduce the size of dwellings being developed whilst trying to avoid any reduction in value. bye- law for minimum height and size standards allows well-planned and systematic construction of house and towns, and provide proper utilization of space.

How ceiling height is decided➱  

Human height in different position

Before deciding the minimum ceiling height we need to understand human height in different positions in a room as seen in the figure the average human height is around 5 feet 5 inches but, we raise our hand upward it’s around 6 feet 6 inch maximum. so considering this fact the minimum height of the ceiling is taken.

Minimum ceiling height inhabitable room➱  

As we know that the minimum height of door height is about 7 feet for all doors in the house each door of the house. must have a minimum height of 7 feet this is because of the fact that human average height is about 5.5 feet and when we raise hand upward is about 6 feet 6 inches. so, there must be a gap between our hand and door frame bottom of the top frame.

Nowadays, architects and engineers keep the floor to ceiling height about 10 feet in most cases. again let’s understand this fact also.

Total floor top to ceiling top is about 10 feet. deducting the thickness of the slab becomes 9 feet 6 inches.

Let’s consider fan handing from the bottom of the ceiling is about 1.5 feet downward sight and when any men raise its hand toward ceiling straight as height becomes 7 feet. So The gap remains between men’s hand and bottom of the ceiling fan will be

 = 9 feet 6 inches -7 feet -1.5 feet = 1 foot or 12 inches. 

Therefore from the above fact we can conclude that the minimum ceiling height should at least 9 feet 6 inches for any habitable room in residential building.

Minimum ceiling height in sunken slab of bath and w / c➱ 

Generally, sunken slab for bath and w / c is about 1 to 1.5 feet sunken below the slab. so, if total ceiling height is about 9 feet 6 inches then space left below we’ll be around 7 feet 6 inches.

Therefore the minimum ceiling height for Beth and W / C sunken slab should be 7 feet 6 inches.

Minimum ceiling height for various rooms in house➱  

living room / drawing-room➱ 

the living room of any house is a place or area where the homeowners and family members gather to spend time together dot it’s an area designed for recreation but also for entertainment space where guests are welcomed when visit the living room also termed as drawing-room.

The minimum ceiling height for the living room from the top of floor to bottom of the ceiling should be not less than 2.75 M or 9 feet 6 inches.

In the case of an air conditioned room the minimum height should not less than 2.4 m or 7 feet 8 inches. measured from the top of the floor to the lowest point of a/c duct or the fall ceiling should be provided.

Kitchen➱ 

The kitchen is the most important and essential room in any house because it is the center of your family’s day-to-day living. everyone’s day starts in your kitchen with a cup of coffee or energizing breakfast to start your day. kitchen space used to make meals for your family in your kitchen and probably even eat in your kitchen.

As the kitchen area is a continuously used area of any house. its ceiling height should not be less than 2.75 M or 9 feet 6 inches.

Bedroom➱  

A bedroom of any house is one of a private room where people usually sleep for the night or relax during the day it is estimated that humans spent our one-third life by sleeping and most of the time we are asleep we are sleeping in a bedroom.

The minimum ceiling height of the bedroom should not less than 2.3 m or 7 feet 6 inches measure from top tiles to the bottom of the ceiling.

Storeroom➱   

The storeroom sometimes attached to the kitchen is the place for storing grains foodstuff and/or junk in the house for their ready availability and use in an emergency.

The minimum ceiling height of the storeroom should not less than 2.3 m or 7 feet 6 inches measured from top tiles to the bottom of the ceiling.

Bath and water closet➱    

It is an area sometimes attached soiled and often a bathtub in a shower.

The minimum ceiling height of the bath and toilet should not less than 2.3 m or 7 feet 6 inches measured from top tiles to the bottom of the ceiling.

Garage➱   

It is a place where house owner vehicle repaired, perked, serviced and also used for storing used parts and accessories of the vehicle,

The minimum ceiling height of the garage should not be less than 7 feet. but generally, it is kept more than 7 feet.

mezzanine floor➱  

A mezzanine floor is an extra floor between two main floors, and therefore it is not counted on the main floors of any building.

The minimum ceiling height of the room with the mezzanine floor from ceiling to top flooring of the ground floor is about 14 feet 4 m.

Minimum ceiling height basement➱  

the minimum ceiling height of the basement should be at least 7 feet to 9 feet.

Standard height of window from floor level➱ 

The standard height of the window from floor level is an important point of discussion while constructing a new house or renovating an old house. the proper height of the window is very important for comfortable living as it permits the Sun and natural air entry from the exact level.

What is window ?➱ 

A window is one type of opening in the wall which provides passage to pass light sound and sometimes air modern windows generally have glazed or covered with transparent or translucent material.

The windows are the most important part of any house which provides light, fresh air, and ventilation in the house. windows are also useful for the purposes of architectural decoration. the windows provided allows light into the room enhance your wall colors or furniture it provided seasonal utility like allows Sun heat into the room and close the opening during summer to avoid outer heat to enter the house.

Types of window➱ 

there are different types of windows available in the market you can choose from them as per your requirements. the windows can have different shapes like square rectangular, and even triangular, some windows open outward, some slide up-down, or slides one side to open these types are available in different materials like wood, steel, aluminum and PVC also used to make a window.

Following are the 18 popular types of the window as listed below- 

➱Single hung windows
➱Double hung windows
➱Arched windows
➱Awning windows
➱Bay windows
➱Bow windows
➱Casement windows
➱Egress windows
➱Garden window
➱Glass block windows
➱Hopper windows
➱Jalousie windows
➱Picture windows
➱Round circle windows
➱Skylight windows
➱Sliding windows
➱Storm windows
➱Transom windows

What is standard size of window➱ 

Windows are a very essential part of any house. for a simple residential building or house, a minimum of 15 percent area of the room is allowed to provide for window openings. that means we can provide a window opening area around 15 percent of the room area if the area of the room is 100 square foot then we can provide one window with size 4 feet x 4 ft for public and commercial building this is around 20 percent allowed,

Width of the window depends on the factors like- 

➱The dimension of the room
➱Use of the room
➱Location of the room
➱Direction and speed of prevailing winds
➱Climatic conditions of the region and
➱Local trends, aesthetic, view, etc

Following are some standard size of windows is mostly used in the house- 

The height of the window generally fix, but it can changed as per architectural and owner requirements windows height is fixed around  feet or up to the level of the door frame or a lintel level,

Standard height of window from floor level➱ 

 There are two levels that are important while placing the window in position.

sill level: – The level or distance from the floor to the bottom of the window frame is called the sill level it is generally kept about 900 millimetres or 3 feet.

Lintel level:- The level from the top of the floor level to the top of the door frame on which lintel is placed is called the lintel. level the lintel is generally provided to avoid direct load on the wall and distribute above wall load to below load the lintel is generally made up of reinforced concrete or cement mortar lintel level is provided as same as the height of the door which is generally 2.1 m or 7 feet.

So, the standard height of the door from floor level is 2.1 meter or 7 feet ,it can be simply calculated by following calculations,

The height of window from level of floor = door height – window height 

in case the height of the door is taken 7 feet and the height of the window is taken 4 feet then the

Height of the window will be = 7 feet – 4 feet = 3 feet 

The standard height of window from floor level is 900 millimetres or 3 feet it can vary depending upon the size of the window, ceiling height,and owner requirement.

Types of doors for your perfect house➱ 

What is door➱ 

Doors are defined as “the movable structure used for opening and closing an entrance or forgiving access in or out of something”

A frame used for given access to indoor or outdoor as to a building or room or giving access to a closet, cupboard etc most doors turn on hinges, slide in grooves, or revolve on an axis

Importance of doors 

We all know the proverb that the first impression is usually the last and this is true especially for entrance to our homes the entrance of any house creates a lasting impression on visitors mind but somehow doors remain unnoticed unless either they are elegantly done or completed in Bad shape.

Doors are the major important element of any home they do not only provide aesthetically pleasing but also have features like durability, strength, water and heat resistance, and it should not warp with time. past days have been gone now doors were used for the mere purpose of maintaining privacy and security. nowadays doors become important aesthetic appearance structure an integral part of a home’s interiors.

Types of doors➱ 

Following are that major types of doors:- 

➱Hinged doors
➱Dutch doors
➱Pocket doors
➱Roller doors
➱Bi-fold doors
➱Sliding doors
➱Pivot doors
➱French doors
➱Panel doors
➱PVC doors
➱Flush doors
➱Battened and ledged doors
➱Bamboo doors
➱Glass doors
➱Aluminum doors
➱Fiberglass door
➱Fiber reinforced plastic doors
➱Steel doors
➱Louvered doors
➱Swing doors
➱Collapsible doors
➱Sliding doors
➱Rolling shutters
➱Glazed Slash
➱Revolving doors
➱Wooden or timber door

Hinged doors➱ 

A hinged door generally made of either a solid wooden panel door or hollow core door affixed to a doer jamb with two or more hinges.

These types of doors are too common and are useful in almost any application in which a doer is required these doors are generally located as front entry rear entry interior and wardrobe doors.

Dutch doors➱ 

A Dutch door also nose is double hung or half door sometimes and is a doer that split in half horizontally allowing the top half to open while the bottom half stays shut secure tight bolt holds the two halves together and it operates as a normal door. nowadays Dutch doors popular for their practicality as well as their old-world feel. these doors are the prime choice for interior doors as well allowing you to keep an eye and ear on children and animals while keeping them in or out of a certain part of the house

Pocket doors➱ 

The special feature of pocket doors is that it gets disappear into a special cavity inside the wall when opened. these doors generally have top hung and slide along a track mounted on the ceiling many house owners choice for pocket doors simply because they like the style. the pocket sliding door is sometimes used to separate two rooms so that they may be joined as needed.

Roller doors➱ 

Roller doors mostly used for garages and storage facilities however they are an extremely trendy addition to a living room for instance.

Bi-fold doors➱ 

Bi-folding doors are generally used for seamless connections between inside and out side of any house. bi-folding designs are not like Dutch or French but they give stacked neatly out of the way providing gloriously open access to the garden and an expansive feeling inside.

Sliding doors➱ 

Sliding doors are also known as bypassed doors and are generally used for locations including large opening as that discovered in a bedroom or closets. sliding doors do not swing open and rather you have to move them on the track and that’s why they do not disrupt other components of the space therefore just a part of the opening is accessible at a time.

Pivot doors➱  

The pivot doors are simply designed to rotate about its vertical axis these doors are available with or without a stopper this door can effortlessly rotate 360 degrees in its own axis.

The pivot doors are made with complicated hinges hidden on the top and bottom of the door which forms the center from where the door Tate’s these types of doors.

French doors➱ 

A French door generally made up of one piece and has the light construction with glass panes extending for most of its length dot they are also known as French windows.

If you are searching for something different and eyes catching French doors would be the ideal choice these types of doors have hinges set up on each side of the opening and they swing to each other in full fill in the center they provide an unblocked view when both side doors are opened.

Panel doors➱  

The past panel doors are very popular for quite some time its name gives the idea about its making that the door is crafted not of one single piece of wood or other material.

Generally panel doors are most suitable for exterior doors but if you want a hey ah fire door that can better deaden sound then you can have panel doors installed as interior doors as well.

PVC doors➱ 

PVC or polyvinyl chloride is a very popular material choice for doors in your bathroom these lightweight doors minimize your work while maximizing your investment.

These doors look like painted wooden doors that do not need any maintenance which is for the absorbent natural fibers of the wood if you go for PVC shower doors you’ll find that they’re simple to install and easy to clean.

Flush door➱ 

A flush door is made of solid block board core vertical Stiles and horizontal rails that create a pre fixed frame and block board is composed of wooden strips.

They bonded under high pressure and temperature using a synthetic resin so we can say that the flush door is a Dewar that is made of a timber frame covered with ply from both sides the hollow part Left on is filled with rectangular blocks of softwood.

Afterward the final decorative finish is given by fixing the veneer on the top it is named as a flush door because it has an entirely smooth surface and if water splashed on its surface it would simply flow off its surface without accumulating.

Battened and ledged doors➱ 

These types of doors composed of vertical boards called battens which are nailed or screwed to horizontal members called Ledger’s the battens used are generally 15 to 18 centimetres wide and 2 to 3 centimetres thick normally narrow battened doors have a better appearance.

These doors can be either braced or braced and framed to offer rigidness in a much better look such doors are mostly utilized for toilets, baths, WC and other rooms as well as in homes where the economy is the prime factor to consider.

Bamboo door➱ 

Bamboo strip can be used in doors and windows, including their frames and so on one common option to the wood item is the jute coir composite board which can be made use of for the manufacture of doors.

Doors composed of bamboo Jude have the benefit of being water resistant, rust resistant, termite resistant, environmentally friendly, biodegradable and expense efficient.

Glass door➱ 

Glass is most commonly used for windows and doors primarily for paneling it depends on owner weather like to use glass doors can be made out of glass for particular areas generally glass doors most suitable location is on the back side as it offers an unblocked view of the yard or garden.

Front doors made of glass also look gorgeous however care needs to be required to guarantee both personal privacy and sturdiness fixing one panel of glass set into wood frames are irregular and gorgeous alternative for front doors.

Glass door is more expensive compared to others and needs more effort to upkeep these doors have more weight than other doors besides being pricey.

Aluminum doors➱ 

When you plan to give elegance look to your house what types of door do you prefer ? perhaps the best choice for you would be aluminum aluminum doors already first choice option for contemporary architecture because of the security, aesthetics and insulation properties it gives.

As it well known fact that aluminum is a durable and sturdy material that doesn’t need too much maintenance there is no doubt about the quality of aluminum. it has already been tested through a bit expensive it’s actually one of the best choices in the door market aluminum doors can be used for both residential and commercial purposes it’s perfect for glazing and glass fronts providing you with a high quality frame.

Fiberglass door➱ 

Generally glass fiber is manufactured by bonding fiber with resin that can be utilized to produce a variety of products consisting of bathtubs, doors, and windows and so on.

Fiberglass is proven to be one of the most solidified products with fairly low upkeep expenses as compared with wood and steel fiberglass doors are well-known as steady as they do not warp, bow or twist.

Windows and doors made up of fiberglass can be offered with wood panels on the surface to surpass the visual Appeals doors manufactured out of fiberglass can be utilized for both outside and interior areas.

Fiber reinforced plastic doors➱ 

Fiber reinforced plastic has high strength it can be put to numerous usages consisting of manufacture of doors FRP doors are available in many colors and surfaces consisting of natural wood surfaces in the market.

These types of doors may have 2 leaves of 1.5 millimetres density and Leafs are molded over a core product forming a sandwich panel FRP doors are one of the popular choice for modern day house construction.

Collapsible doors➱ 

The collapsible doors are composed of vertical double channels (20 X 10 X 2 millimetres) join together with hollows on the inside to create an artificial gap channels are spaced about 100 mm to 200 millimetres apart and braced with diagonal iron flats which allow the shutter to open close giving an appearance of a steel curtain the doors shutter operates within two rails one fixed to the floor and the other at the lintel roller fixed on top supports the equivalent movement in both directions for easier operation.

Sliding glass doors➱ 

These doors are generally utilized where there is space limitation for the swing of a hinged door or for aesthetic purposes these doors are commonly used in commercial structures.

The doors shutters slides horizontally along the tracks with the help of runners and rails generally the door is hung by two trolley hangers at the top of the door running in a concealed track while at the bottom rollers are provided to slide the shutter in the channel track for providing easy movement plastic rollers are fixed at top bottom.

Rolling shutters➱  

Rolling shutters are generally used for shops /go downs this shutter works as a barrier and provides protection against fire and theft’s wind and hails.

The rolling shutter is made of steel slabs called laths or slates which are around 1.25 centimeters thick interlocked with each other and coiled upon a specially designed pipe shaft called drum mounted at the top.

Such an arrangement is made that shutter moves in two vertical steel guide channels mounted at the ends the channels may be made of steel sheets deep enough to accommodate shutter and to keep it in position.

The rolling door is raised to open it and lowered to close it on large rolling shutter doors more than 10 square meter the action may be motorized.

Glazed / Slash➱ 

Glazed or Slash doors are the same as framed paneled doors except one of the panel’s is replaced with a glass to improve visibility of the interior room.

Revolving doors➱ 

This door has a central shaft with four wings that hang on it the shaft rotates around the vertical axis within around enclosure.

The doors central shaft is fitted with a ball bearing arrangement at the bottom which allows the shutters to move without any jerk and making noise.

These types of doors may be fully penalty glazed or partly glazed.

Wooden or timber door➱ 

These types of doors are primarily used for interior door applications timber is the oldest material used for the doors and timber never seems out of fashion there are many good reasons for using wood such as wooden doors provide soundproofing insulation and security. they are easy to install and clean. they have a long life being a natural material they have a different appeal. they do look elegant they are very costly.

How to reduce construction cost➱ 

Building a dream home is everyone’s aspiration everyone person wants to construct a Ahmed where they can cherish their memories but when people want to make their dream into reality it is very hard to fulfill it is because house construction cost is not cheap nowadays for the middle class family is about investing their whole life income in building a home.

That’s why many people find it a large investment in their life for this reason they try to save as much as possible to get the optimum value of their price also some people go for loans that are why it is necessary to effectively use the money to get maximum benefit it is not a big task.

Selection of plot➱ 

Because that can reduce your transportation cost for a lifetime but many sellers are there who take the opportunity of high demand and sell the roadside plots at a very high price so be careful while choosing the plot if you are getting it a little far from the main road then it is okay.

Conduct soil test➱  

While selecting a plot just not focus on the communication facility but do soil test which is a much essential part of the construction because there are different types of soils are available and each soil behaves differently before buying the plot check the soil if it is a paddy field agricultural field or soil with hard soil.

Because if the soil is not good or if it is a loose soil then there you will have to expense a huge cost and after if it comes to know that plot having paddy field then the foundation cost is huge and again to get permission to make the home is huge.

Confirm electrical and water supply an area➱ 

If there is no electric and water connection near your plot then you have to apply for a separate pole connection near your home and have to make a separate connection for plumbing which is again expensive so look after these factors before buying a plot.

Choosing construction materials➱ 

In any type of construction building materials play a major Cost effective role among all the construction material bricks, cement, rod and sand make a large part of the construction material if you purchase material. in the lot main one order for whole material manner then there will be less expenditure regarding construction material. because the dealer will give you more discount as you purchase more amount of material.

Prepare structural drawings➱ 

Preparing structural drawings for the house is essential the majority of people ignore this and don’t know about the structural drawings of buildings they only thought about the architectural drawings of the building but structural drawing is all about foundation plan detail framing plan detail column and beam plan detail and other structural components of buildings from this structural drawing how much amount of rod send cement and bricks will be required can be calculated in advance and if this is done accurately then there is a chance of saving lots of money.

Saving and finishing materials➱ 

Not only is the construction material only responsible for rising costs along with that finishing the material is also responsible while we consider finishing work there is flooring material doors and windows and especially wooden works for interior absorbs a huge cost.

But this can be reduced if you are choosing proper material and buying material in bulk amount at a time if you are purchasing this material in phase by phase manner the shopkeeper may not give you a discount but if you are purchasing in a bulk amount and from one shopkeeper then you can save your money.

Do not make change after construction starts➱ 

Sometimes people approve one plan before construction and during construction they suddenly change their plan this is one of the major reasons which again increases the construction cost dot try to avoid this thing unless and until it is necessary.

Go for pre-fabrication work➱ 

To minimize the cost of house construction you use modern technology use prefabricated parts for the construction of your home in this type of construction a part of the building is constructed at the factory or in a separate place and then combined to a site to make the house it has a lot of benefits it not only reduces the cost but also reduces the time of construction.

Use fly ash instead of red bricks

 If you want to reduce the cost then choose to fly ash bricks instead of red bricks or other bricks fly ash bricks are less costlier than red bricks but have good strength for construction . it can reduce the cost of construction in a considerable amount.

Select good color and putter➱ 

If you wish to reduce color cost then go for lime based color put the color twice to make the color brighter . don’t use putty generally putty is often used when we need a smooth wall surface or the wall is very rough or there are larger sand particles showing to avoid extra cost for putty always purchased the standard size of sand for the purpose of plastering.

Saving in labor cost➱ 

Labor cost is also a large part of the construction which cannot cut easily but try to calculate the works in hours how much labor will be required to finish work and how much time in this way you can save your cost by estimating the labor cost otherwise the labor will work according to their time and you have to expense more.

Saving in machinery cost➱ 

Construction machines are always hired on a rental basis and their rental cost is too high so try to take maximum advantages of construction machinery in a calculated way by which construction cost can be saved.

Saving and flooring

flooring can be done both costly or economically tiles come in odd pricing range select one of them according to your budget also cement flooring is a great option. to reduce the construction cost and one of the long-lasting flooring.

Saving in wooden work➱ 

As far as possible if there is no essential need for wooden work try to avoid it you can also try to avoid the use of costly woods for construction instead you can use a jack fruit tree while Jack jungle jack and similar wood most available in your place to reduce the total cost of wood up to 50%.

Selecting good shape of house➱ 

The shape of the house also contributes to increasing the cost of construction when the size of home increases it increases the surface area and ultimately the cost of construction so try to sign house such a way that it will reduce the surface area and reduce the cost.

Reduce numbers of wall➱ 

Make the home more spacious by reducing the number of walls it ultimately reduces the surface area and also decreases the cost it also permits natural light to enter the house and decreases the number of electricity expenses.

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Pile Load test

Pile Load test

PILE LOAD TEST


INTRODUCTION➱

Something relevant for onshore and coastal areas where the possibility of load testing is feasible whereas for offshore conditions full-scale load testing is not feasible because of several constraints In any case to understand what involves such load test will be very useful so that you can see what alternatives can be worked out for offshore conditions.

But in the near shore around less than 20-25 meters we have done pile Load testing but quite cumbersome quite expensive and time-consuming So the pile Load test if you look at the design of foundation you know there has always been a debate because of the uncertainty associated with the soil parameters.

Always it is understood that design is verified by testing to full scale at the side of the final construction If you look at many of the international course obviously they state that in the engineering based design is not hundred percent sure.

So if you go back to British course or European course including Indian course specially for pile foundation, you will see that every pile needs to be tested to its capacity ,

So if you have seen in a construction site several hundred piles testing every one of them becomes you know elaborate as well expensive time-consuming it puts the whole project in a different schedule of construction activities,

So you select critical piles or piles that may represent actual site conditions So among hundred number of piles may select say 2 piles or 3 piles which may represent actually the site conditions ,So normally most of the modern-day projects we take about 3 to 5 percent of the piles,

That means if you have hundred piles you do the testing of 5 piles So you select them in randomly to distribute all around the site in such a way that you can extract information from this pile testing so that you can represent them in the design process,

But by doing that what you are actually going to do is you take this so-called test parameters and then that calculate and go back to the design revisit the design and adjust the design parameters to suit the tested pile information,

So if the tested file is giving the design or the failure load is lower than the design load means your design parameters what you have used in your calculations are on a higher side or vice versa So you can go back and then adjust the parameters until that you get the design capacity versus failure,

Load is almost close by so this adjustment is even now many of the projects we try to do this so that in the future installation become almost reasonably correct So that means this testing has to be done up front before the construction starts so that is the idea behind pile load testing,

That means you get a comfortable level of confidence which is very essential for foundation system,because you cannot have an uncertainty on a foundation for structure which may actually pose a big threat So the pile Load test has been there for several decades for onshore and offshore projects of near coastal areas,Several kinds I would say So since,

What is the purpose of pile load test?

PROCEDURE OF PILE LOAD TEST➱

Now you see the procedure how we want to start the project with low testing we want to do the load tasting up front before the actual construction starts so you can say sacrificial testing that means once you do the testing of this piles the piles will never be able to use it because you already have failed the pile to ultimate load capacity that means you have a different category of testing

Or you can actually test the same pile which you want to use it as a part of the structure that means you cannot fail the pile but you can actually apply the loading until the load that it may get during its service You know so you can see here now planning is required what type of testing is planned for that particular site whether you want to do a full-scale failure to load test or you want to a working load test,

The test that may actually take you to the level of working load and stop then you actually construct the structural system on top of it So this pile Load test is quite useful in a sense so we will look at various test and the procedures available for us So we will be looking at both horizontal load test and vertical load test,

You know we have specially the coastal areas and the berthing structures and offshore structures we have considered amount of horizontal load compared to onshore structures And then we will look at some of the testing some special testing by which you could actually get the similar information,

But that kind of empirical method you do some testing and extract the information and prorate it to obtain the axial failure load which nowadays seems to be very economical and is quick specially the dynamic testing and some of these are commonly used,

Pile Load test

So if you select 5 percent of the piles for testing using gravity method the remaining 95 percent you know still uncertainty exist because if you look at a site your construction site say 1 kilometre by half kilo meter wide industrial construction and you select only 5 remaining 95 percent of the pile is distributed all along this site,

Now you may conclude based on 5 piles that these remaining piles are safe we have adjusted the design but what surety you have over the distribution of soil within a 1000 meter length it may be very difficult decision So instead you go for the remainder of the pile with simplified method instead of going and putting a big weight and then measuring the displacement and strain you do a simplified method of pro rating the capacity based on certain small scale testing which is what we used in dynamic testing and which is very useful in many cases,

It proved to be So if you do a full-scale testing and on the same pile you do a dynamic testing compared capacity then you can actually get a very good feel how the dynamic testing is fairing with regards to the full-scale gravity testing and your design your theoretical design you have 3 numbers to compare and then you can come to a conclusion,

 And then the remainder of the piles you go and do a So you can see the correlation is very important from gravity testing to a dynamic testing to a engineering design then you go back and do the remainder of the pile you have only engineering design adjustment plus the dynamic testing ,

So this procedure is adopted in most of the large-scale projects but of course if you look at only some projects were only 5 piles 10 piles are there and subject and dimensions of the structure is so small like 50 meter by 50 meter the variability may not be that great so you can do only one pile test and you can leave it,

 And in the application of such simplified methods for pile monitoring for offshore structures is very much useful like what we have learned about your medical scheme to calculate the number of blows required to drive a pile to a particular depth of penetration using a particular hammer,

You can back calculate and it is called pile monitoring system that means you will use the information during driving and then calculate what resistance it would have been offered by the the soil during driving,

And then you just adjust it to long-term capacity using several parameters and then you can predict or at the end of driving you can say the pile would have achieved this much capacity,

Now what you did avoiding here you are not going to place a big weight and try to do a measurement of displacement which is quite cumbersome especially when the pilot very large and the load is huge ,

And that is why the pile monitoring system is one of the indirect means of getting pile capacity in offshore condition and that is what we are going to discuss at the last And in the recent times in the last 10 years,

Or so another method of permanent implant of device into the pile system which is adapted for concrete piles at least You know basically before you install the concrete pile you would a load cell at the bottom of the concrete pile itself,

And just cause the pile and afterwards you have a activation system a wire will come to the ground so you can activate the hydraulics and you just push the pile against the soil resistance And this can be done for ultimate test,

Or it can be so this O-cell test is also employed in some of the onshore projects bridge projects in US but very in this part of the world because it is quite expensive you need to embark a complete load cell inside the pile itself,

Permanently you cannot extract them afterwards so it is just left over there So this O-cell is basically Oster berg cell name after the person the professor who found this method for one of the bridge project in US,

It is in use for quite very useful and few projects we have used it for offshore or coastal so we will go through each one area by little bit detail So the purpose of pile load test is to find out the install pile capacity and verify and remove the uncertainty of associated with the assessment,

That we have gone through do during boring taking Sample and then to laboratory test and then properties and unknown properties are calibrated using past you know information So all those things will be removed once you have the actual capacity versus the displacement,

And to assess the load displacement basically there is no critical information that easy to relate the capacity versus displacement You might have already got the methodology to evaluate the bearing capacity,

 A multi layer site what you saw was basically a single soil layer giving a theoretical relationship between the capacity and the displacement whereas when we have a multi layer soil the behavior itself is going to be complex and the only way to get the load displacement relationship is to carry out complete load test,which will be a prototype in nature you are not doing a scale model like our laboratory,

So the primary purpose is to link and assess the load displacement characteristics of a particular pile at a site So the test can be of in fact 3 categories basically the one that normally carry out is the static load test the load is static in nature and that the dynamic load test which is what we were talking about,

The quicker and the cheaper methods Then we have the bidirectional method using O cell you can actually do this way or the other way In the static load test we have got variety of load application methods,

One is the constant rate of penetration imagine if you have the pile already installed and try to do the loading the displacement is not under control so that means if you go by this method whatever displacement comes you will actually note down whereas if you actually control the displacement by changing the load according to the displacement characteristics,

The rate of petition can be controlled So but the first one is quite obviously very difficult to do because you have to continuously having a monetary system of displacement and adjust the loading according to the rate of penetration,

Not many of the contractors have this facility because you need a feedback loop so that when the displacement increases you have to decrease the loading and it is only feasible by hydraulic means where as normally most of the most load test,

You see in the field they all just put big weights so removal of weight is going to be very difficult So most of the time we do maintained the load test you put one weight weight for several hours according to the procedure and monitor the displacement,

If the displacement become constants that mean for that particular load soil has achieved its maximum possible displacement Then go to the next load displacement and apply the loading wait for several hours and vice versa you remove the loading and look at any elastic rebound happening or is a plastic failure,

So basically this maintained load test is commonly used in most of the projects very rarely we go for this particular method Dynamic load testing we have very similar idea like you know the pile hammer when you take a hammer and drop onto the pile and you see the stress waves travel through the pile and get reflected,

If the absorption is not enough and you measure the statistics of the transmitted stress waves and reflected stress waves and depending on the reflection and the transmission you back calculate using the same principle,

What we were looking at the the dynamic equation and calculate that what would have been the resistance offered by the soil because this much waves has reflected back from the soil itself So that is indirect means but before going and doing the actual testing at the site you may have to actually do a calibration in a known material which is easy to do,

After that you can compare with the known material versus actual pile at the site this is you got 2 types of tests one is the high strain dynamic testing the other one is the low strain dynamic testing just the weight of the hammer and the low strain dynamic testing is normally preferred because for concrete piles,

If you do a high impact the pile itself will actually fail Pile monitoring I think we will talk about it little later it is a simple idea of using the driving information or driving records number of blow counts and you know the duration between the blow,

Sometimes you will have major stresses at the pile tip at the top and calculate back the resistance which is also is dynamic because you are using the pile the hammer impact loading Bidirectional method is quite useful only for the O cell testing which is you can do testing in both directions, because the load cell itself is planted into the the pile foundation,

So you can do vertical load test you can do compression tension I think obviously some of the piles in coastal areas for example berthing structures you will have compression loading and tension loading depending on the magnitude of horizontal load,

So the pile needs to be tested for compression and tension as we calculate the capacity you know pile capacity we calculate using skin friction pleasant bearing that is for compression For tension you will have only skin friction depending on whether the pile is plugged or unplugged,

You will see the internal and external So in this case the tension testing is required for only few number of files for example even if you design a structure the whole structure does not have any tension loading that you do not need to do this type of testing,

But most of the berthing structures will have tension because the gravity loading is very less and it is predominantly going to resist the horizontal loads like ship berthing structures so you will see a huge amount of tension coming at you have to make sure that the pile has sufficient penetration to take the tension loading,

It is not the whole structure will pulled off In many cases what we normally do is if you are unable to penetrate that much longer than you actually do a anchoring of the pile into the ground means you will do a smaller hole we will talk about one of the days,

I think later in one of the sessions about encourage files only for tension loading which is very essential for such type of design Then we have also lateral test static and cyclic and you can see here static test is going to give you certain capacity which will degrade when you apply the same loading,

Several times because the top layer of the soil as we have learned from our P-Y curve near the seabed you can see the soil gets disturbed quite a bit because of the repeated nature of loading and degrade the displacement or increase the displacement degrade the capacity,

So we need to see after how many cycles the capacity gets that means you would see that displacement would be more Then we have loading limit whether to load to the ultimate failure stage that means the pile will go into permanent deformation and the soil or you want to do a routine test by which you will not destroy the pile,

You will only do a extend of maximum working load the structure may get and stop it so that the same pile can be used for permanent construction as part of the structure so either way we can decide Only problem is there is an uncertainty in the second one you know you do not know what behavior,

It will go through after it achieves that so-called working load limit because it can fail straight away plastic deformation can happen or it can have a redundancy after that which will not be revealed when you do the working load test,

Whereas when you do this you will be able to find out at what load the pile is failing then you know what is the factor of sifting because the factor of safety is defined as the ultimate load by working load or ultimate capacity by working load,

So you will only be able to ascertain the factor of safety if you are able to find the ultimate load of what you will not be ascertain that factor of safety because in the working load test you only have that level it may actually fail after just going slightly higher than the working load which will not give you the comfort-ability of the factor of safety,

So that is why the working load test is normally not preferred but then cost versus your factor of safety and design requirements You have to decide how many number of piles you want to do ultimate load test and how many you will do a working load test,

But of course if the test result so large scatter then you will increase the number of piles that you do testing If you do a 5 piles and all 5 of them are shows very reasonable matching of results and you may have actually conclude that no further testing is required but each one of them shows different results and different variations in displacement characteristics you may actually decide to do,

Furthermore addition to the pile testing which again is is actually an procedure is decided by the the site representatives I think we have discussed the performance is design validation I think the primary purpose is design validation whatever corruption you have made during your bore holes and to the design stage,

You would like to validate that those assumptions are nullified so that your process of construction can go Quality control for sure in concrete pile is one of the biggest worry in fact steel pile you do not have such issues but the quality control of concrete pile construction,

Because everything goes underwater you have to displace I think we have discussed about the construction of concrete pile you have to displace the slurry which was poured inside by means of good quality concrete but the quality could not be ascertained because nobody can go inside So when you do this kind of low strain dynamic testing you could also assess the concrete the honey combing structure,

If the concrete is not done properly you will see that the reflected waves will differ from the solid concrete that if you have you can actually have uh testing of pile itself whether the pile is sound enough to reflect and transmit the waves or if the pile has got low honey combing inside also can reveal Similarly for steel piles if the file has been broken during driving and if you do this testing and it will reveal that if the stress waves are not coming you could easily find out where is the fault,

So that is the idea behind this the low strain dynamic testing So basically quality control of the construction itself can be verified by means of carrying out cross correlation test Sometimes you do a design development you know you basically you have a large number of some projects of thousands of piles like if you go to some of the large-scale industrial projects,

You may have several hundred piles So you do a representative pile testing and use that information to further develop and then come up with a design procedure In many cases if you if you look at some of the large-scale projects they actually develop new design procedures specific to the site using the design data collected from the pile load test plus the portable information,

And they come up with their own design strategy and the you know you do not need to follow the standard procedure given in either any of the codes or regulations because it is proved by testing at the site so that will be done sometimes And in many cases always you will use it for further refinement of academic interest,

I think these these are secondary but of course insufficient site investigation normally you do not do a construction without the site investigation but then all depends on you know the the owners intention sometimes some government organisations may not be able to do a site investigation,

Before the hour of contract to the contractor because of the nature of limitations they have They may not be able to allocate funds separately for site investigation and separate for construction it is part of the construction itself So what happens is when a contractor comes to the site they have no clue what is the site so they will be doing the site investigation so that is the time when the design becomes difficult the design has to be evolving based on the available information,

But not actual site information Many cases that happens so you do that at that time when the project starts you have assumed certain parameters during design and then you proceed with the construction but then do the testing 1st Once you do the testing your assumed information verified and several other limitations on you know basically cost is one of the primary parameters,

Nobody wants to do testing if they can live an engineered design I think everyone will be happy but that will not be the Now guidance from Handbook of pile load testing this is just give you an idea of how to decide how many piles is good for a particular site,

You know just of course this is only a guidance it will need to be decided by the site engineer and the and the owner of course for sure depending on how much of time and money is located for that purpose,

But typically you can see the complex or very much unknown ground conditions you know it is isolated place no one has constructed in the vicinity so then probably you can go for a large number of So you see here they recommended is 1 preliminary pile test per 250 piles so that means preliminary means this pile will not be allowed to be used in the permanent construction,

So you do a separate file at an isolated location within the periphery of the the boundary where the structure is going to be built It will not be within inside because what you do not want you do not want to fail the soil between close vicinity of a working pile,

For example you have a pile here and just half a meter away or 1 meter away you want to construct a pile and fill it which is not very good because you cannot install another pile in the because the soil already have mobilized its full strength and failed,

So normally you will go little bit away but not very far you cannot do the testing several kilometres away it does not represents the actual site conditions So within the parameters probably representative location you will do a 1 preliminary test for 250 piles,

So you can see here it is only a guess there is no rule book or it is not representing some kind of you know relationship it is only a guess that it may actually give you some information plus 1 working pile test for every hundred piles,

That means among the remainder of the piles every hundred piles you select one and then do a where the the ground conditions are very much unknown probably not very clear No previous pile test data is available in the site new piling technique is used in case in that area every time,

They were using a concrete pile but suddenly you are going to use a test you are going to use a steel pile then it is an unknown experience very limited information available in such cases you do this Where as if it is the other cases you know your risk is reduced with reasonable information then you can increase or decrease the number of piles per testing,

So you see here 1 preliminary test for 500 piles which and then for very low or in fact you got plenty of data then you can also use 1 in 500 1 in 100 or 1 in 200 In fact codes are not suggesting any of these numbers because they leave it to the,

You know the owners or consultants who are representing the design validation So normally we design something very similar like this 1 in 250 but not very projects will have 250 piles you know maybe 10 20 50 so if you do one pile that itself is good enough,

So this is only a guidance which if you are representing your company for pile testing or if you are writing a specifications for pile testing you can put that kind of number Rabbit load test versus dynamic load test you know the kind of capacity that you expect you know 30 mega Newton is $ 3000 tonnes and what kind of hammer,

You will be using just information that you can use it that much is practically possible to do the testing So if you remember we were talking about pile capacity in offshore pile system I think we were talking about 20 to 30 mega Newton for each pile which is something like this,

So it is not that we cannot do it can be done but at a very expensive system design because water depth is more and you want to design a reaction pile for such type of testing will become costlier than your jacket so that is why we avoid,

I think we just discussed about static maintained load of test versus static penetration test or the so-called constant penetration test you can read some of the information about the past history of what was done the maximum load of what was achieved in the previous several years it can be done to that much of load 3000 times,

So you will see if you go around some of the the pile way construction I think MRT construction is going on I think 6 months back so many places they were doing pile testing for the pillars the big pillars you will see that a use platform is built and concrete blocks are stacked upon each was about 600 tonnes,

So you can see that the bulkiness of that platform to load this 600 tonnes because you calculate a 600 tonnes by either by sandbags or by concrete blocks you will get 3 to 4 layers of concrete blocks will come So safe working load ultimate load and design verification load sometimes differ from we discussed about safe working load is a working load of the pile as per the design requirement Ultimate load includes the factor of safety that means either 2 or 2 and half or whatever the design factor of safety,

As per the design code If it is a IS code you normally use 2 or 2 and a half whereas API code we use 1.51 through and so this is the test load that you will apply if you do ultimate load test Sometimes design verification load is in between these 2 we go 50 percent overload instead of failing the pile,

We do a pile load test taking between the working load and the ultimate load sometimes 25 percent higher than the working load Still the pile can be reused because you are not failing it but it is slightly overloaded just to see that how the behavior goes,

Because if the pile fails immediately after reaching the working load after say 5 percent the the factor of safety is not there anymore So design verification load it can be any one of them or it can be in between also A typical onshore pile load test we will just read the methodology how it is carried out,

So you can here this is a good ground condition means the ground at the surface is reasonably good So we have a gravity based support system something like this you construct pillars sometimes we actually use concrete blocks,

You know simply put on 4 Corners make a steel beam something like this and just you have your pile previously installed which is going to be tested and then with a prepared pile head it could be a concrete piece or steel piece placed on top and then you start stacking up your weight because while you are stacking up because people have to go up and load,

It or you your Crane has to bring material and then just keep stacking up And then you will place a hydraulic jack or Jacks 1 or 4 of them normally 4 of them is used and just jack it up So what happens is previously when it was loading is done at that time no load is going to the pile and safe because for a longer duration,

You do not want to keep this condition because it will topple or slides down to sideways you will be putting big danger on the pile itself as well as the system So normally you have this is called Cantalage weight distribution system this is feasible only when the ground conditions are good number 1 and also the the distance from the pile should be sufficient enough that the load does not actually alter the soil conditions in the vicinity of the pile,

Imagine if you do this and if the soil gets actually squeezed and get compressed the pile capacity that you are actually going to measure is not going to be represented in the actual site condition because already the soil has been compressed and consolidated,

So that is why you have to keep this support system quite away from the pile itself so you have to keep it 3 diameter to 4 diameter away so this cantalage becomes actually very large depth girders normally you will see 2 meter-3 meter girders spanning between the supports something like this you have to keep 10 meters away if it is a 2 meter-3 meter pile,

So they will be away so that that influence of the reaction is not coming back to the soil So this is a typical onshore pile load test that using you know spread footing type reaction system so that is the idea put behind So this test can be repeated if it is a working load test you just load-unload load-unload,

But load will not be applied in one single stage normally because then you you will only get one load one displacement relationship So you actually divide the total load into say several steps if it is a 300 times divided into say 5 or 6 steps and put 300 into say 6 steps means 50 tonnes and just look at the displacement then go to hundred tonnes wait for some time and till the displacement becomes constant,

Then you take the displacement reading go and put the further loading so it is just done in steps And then similarly you can do a unloading so from 300 you come to 250 and 200 and so on so you can see whether the loading path and unloading path is same or different,

If there is a plastic deformation then you will see that there is a different load path from loading to unloading so that also can be verified If it is a soil condition that the top surface soil is not good or it is going to distribute the load very close to the the pile that is being tested then you may actually look at installing additional piles and this is the case most of the cases it happens like this So install additional number of piles in and around the test pile,

Normally 4 number of piles are installed and you prepare a cantalage which is nothing but a just a grid of beams which will support these weights to re stacking during unloading process and then when you want to do the testing you simply use the hydraulic jacks to activate,

And then lift it up So you can see the difference between soft bound you know soil condition at the surface to good soil condition the expense increases several folds You can see here here just only a simple pedestal support quick to make easy to remove where as when you go to this one you can see here for one pile load test,

You are installing 4 number of piles so you can see the the multiplication of the time and the cost and the removal you have to remove these piles you cannot leave them there itself unless it is isolated place,

So basically the procedure is same only the difference is depending on pile condition you will do the support reaction and cantalage according to the requirement And if you are going to do the same testing in coastal waters 5 meter 10 meter 15 meter 100 meter water depth can we do this,

So that is where we bifurcated into a different idea if it is a 20 meter water depth yeh probably you can design a pile which will be directed around the other load testing pile and make a platform something like this and then construct this frame load and unload can be done up to say 10 meter 15 meter 20 meter,

But when you go beyond 25 meters will easily see that the diameter of the pile tested and diameter of the support frame the diameter 0 becomes too large If you actually have to do a pile test in say jacket location 100 meter water depth because jacket is still not there because jacket will come only after you complete all your design and everything,

You cannot do testing of a pile through a leg for sure it is impossible So when you want to do this 100 meter water depth imaging you may have to actually specially fabricate a jacket vertical in nature is not it something like this and keep the frame there and put the pile inside and do the testing,

That means, it becomes another project so that is why this pile testing is completely not feasible so maximum pile testing I think for coastal areas people have done up to 20-25 meters maximum beyond which you will see that the design of the system itself becomes a problem,

Specially when you are doing so much loading coastal areas 300 400 500 tonnes But for jacket type of structure if you want to mobilize weight of 3000 tonnes which is becoming a bigger problem so how to avoid even in coastal areas even in land based structures can we do testing without this weight,

This is one of the very good idea so that you can avoid for example if I go and connect this beam with this pipe so what will happen I do not want to put the weights here so instead of using this weight as a reaction what we want to do is we have simply weld this this beam with this pile So what happens,

When you are actually putting up the hydraulic jack the reaction will come from soil itself so that is basically the idea in the recent times no one wants to do a this this is called Dead weight method of testing,

And you can just look and eliminate the so much of weight bringing the weight stacking upon and removal can be removed provided these piles which were installed as a reaction pile or a support pile has sufficient pullout capacity otherwise that pile will come,

You do not know whether you are measuring the this displacement of this pile or whether you are measuring the pullout of the other pile which will become a very complicated situation,

Pile Load test

PILE LOAD TEST PART -2

Let us continue with the pile testing so by this I think you could understand the 3 concepts concept 1 foundation by means of simple spread footing for the cantalage itself And basically pile foundation where the ground condition does not permit Load distribution around the test pile the primary concern is we should not put undue load to the pile soil interface which is being tested,

So that is why we have to space it larger enough so that the pressure from the thus upload pile cantalage support pile does not affect or influence the result of the test pile itself that is one concern The 2nd concern you know when you are doing measurement of a displacement of the pile being tested you need to have a firm ground or a darter line by which you will be able to measure the the settlement,

For example in this case the ground condition is good and also you have accessible ground so you just put the darter line which is not going to change over period of time during the testing So if there is a easy way of putting a dial gauge with respect to the ground and then measure the movement of the pile,

Now if you go to the offshore condition what happens if you have no firm condition or firm ground you have to use only the the pile which is supporting the cantalage but at the time of testing it is not loaded anymore,

So you can use that as a reference and use a beam or some welded connection so that you can use the dial gauge So what we need is the the firm place it is not moving during the testing so that is one of the 2nd concern And then when you are doing the testing,

In any case it is not influencing the soil-pile interface or the capacity of the test pile which is being done the now-that is one of the idea so you need to keep it faraway 3 to 4 diameters so your cantalage anyway will require a larger space to stack up the waste and things like this Very rarely in coastal areas we do this because,

It is very expensive one of the tests could take months to set up and do it and bring back A typical cantalage test which is just on land so you can see here even in this particular case it was done in one location in Kakinada where last year before you can see piles were driven so this ground condition was so bad that even you cannot spread the load which coming from so much of sandbags,

So we need to have piles going down to a firm ground because the total top 15 meter of soil is play soft clay and if you try to put some spread footing it will definitely think under this kind of support reaction load during stacking and then you cannot retrieve and every time when you just load and unload the foundation becomes no use,

So that is the picture that you are seeing the pile is being tested which is at the middle and basically the pile will be provided with a pile cap steel plate and these are the jacks which are just placed between the cantalage and pile head just to stack of you know And the dial gauge can see here is placed at this place and this is the reference to the pile head itself,

And this is the bottom line which is not moving So when the pile is moving up the dial gauge will show the displacement every time when your how much pressure you are applying The alternate ways also because instead of instead of going for cantalage with self weight or dead weight,

We can actually use this method by using the pile itself as a reaction frame So you do need to stack up weights only thing is the load is produced onto the test pile by means of the compression load because you are just holding this cantalage frame on the sides using the pile so this is being a welded connection,

So always this anchor pile will be under tension so you need to have sufficient capacity of the anchor pile so that so that means if you are testing a 3000 tonnes here each one of them will have to be divided by 4 and recently have designed with the adequate penetration because it is only tension At least this pile have the N bearing whereas the anchor pile will not have N bearing so you need to have sufficient penetration sometime it may become very large,

And basically bigger bigger than the test pile because you need bigger capacity in tension than the test pile is being a compression capacity so you have to be little bit So that is where this method becomes little bit difficult because it might become very expensive,

When you compare with this maybe better because you do not need to mobilize so much of material movement every time because it is not one-time you will see that later on the sandbags have gone back and forth several times because you have to do loading sequence and unloading sequence and you have to repeat the test at least 2 times,

And that is where you find this is a time-consuming process and also very expensive Anchor pile seems to be very good but then caution needs to be taken in terms of design make sure that when the pile is being tested this is the anchor that you have designed it is not going too much,

Otherwise you will be measuring actually relative movement of the pile anchor pile and the pile being tested Typical reaction pile setup so you can see here this is the pile being tested pile requires to be tested otherwise you have the jack being placed at the and these are the pile heads the left side and right side you see the pile heads which the piles are being driven with the pile head,

And when you just push this hydraulic jack upwards the reaction being applied to the test pile and these the reaction piles on the left side and right side should have sufficient capacity and basically that should be designed And just a closer view of how the hydraulic jack is placed in the girder,

So that it reacts against the test pile as well as the reaction pile Another load test using concrete blocks instead of sandbags many times people use this because it is easy to handle and can be used in multiple places only require storage,

But in any case in construction sites you will find many of these concrete blocks uhh spare capacities available there but many times people use these sandbags because easy to dispose because they can be used for construction work no extra storage space is required and each one of them will be weight before placing it on the top so that you know the weight what it is only the stability of them,

Sometimes bit of a worry because even a small eccentricity caused by either placement or by you know stability the whole thing can be turned In many places if you notice pile load test failed because of the cantalage tilted or cantalage failed which will cause quite a bit of problem,

Whereas using concrete blocks is quite useful because it is very stable sometimes these concrete blocks will come with a sheer case so you can have an opening at the bottom and you can when you place it it will not go anywhere and horizontal stability is well-established,

We can have precast blocks specially for testing not just for any other purpose So the ultimate load test is basically done to the load which is taken to the maximum failure capacity of the pile which will be 2 times or 3 times depending on what the factor of safety used in the particular project of particular core of design,

It is most of the time for IS codes we design for factor of safety for 3 which is for concrete piles which actually says 2 to 3 but then mostly we use factor of safety of 3 that means you find out what is the load that is designed for for working conditions take it to factor of safety of 3 and then find out So typically,

If you look at 300 tonnes is a working load most of the 1 meter-1 and half meter diameter piles then you multiply by 3 you will take to nearly thousand tonnes so imagine thousand tonnes what could be the requirement for dead weights Working load test is typically one and a half times safe working load so we want to go for slight overloading,

But not to the ultimate stage As long as you want to see passing of the working load and also have little bit of budget get depends on how much design margin is available at sometimes be reduced to 25 percent we normally call it overload test Even mechanical devices nowadays everyone of them the working load test is not acceptable,

You have to go for slightly overload because if the load exceeds the working load even by slight amount it should not fail so that is why overload test is about 25 to 50 percent So the 2 methods of testing that we were discussing the other day is constant rate of penetration or maintained load constant rate of penetration is just you can see here 0.75 mm per minute,

So it is a quite slow process and that eventually required by the British code 800 is for design of foundations And maintained load test typically used in most part of this construction site in India is very easy to carry out you do need a sophisticated loop back system simply put the weight and get the whereas the constant rate of penetration,

You need a good amount of instrumentation to read the the penetration backward and adjust the pressure accordingly and it can only be done by hydraulic system not by dead weight and cantalage method it is just not feasible,

Whereas the maintained load test even in a very simple method which you need a dead weight and a jack And the load shall be maintained constant until settlement rate is decreased to 0.25 mm per hour so what we normally do is use you set up your cantalage put the weights safer example 900 tonnes divided into say 5 steps or 6 steps,

So the step 1 of the load and this activates hydraulic jack to transfer the load to the test pile relieving the Anchorage piles or support system and then monitor the displacement Initially displacement of the pile may be larger slowly  reducing indicating that the soil has achieved its failure state at that load and then it will go constant or may slightly increase in a very low implement,

So once you see that it becomes flat the displacement graph is flat that means you are not expecting any more images settlements you may actually expect long-term settlement which may be several years which is we are not interested in that So basically then how do you decide when to stop the or when to restart,

The unloading process because every time you are going to unload it bring to 0 then stack up to the next increment So 1st time say you arriving 200 tonnes and bring to 0 that means you have to take out the load and load it again to 400 tonnes so that process when you want to start as soon as you see the displacement relationship is going flat,

That will be better but if the rate is still within this then you can go that means when the displacement is happening you cannot do unloading process So maintained load test is quite simple we will see the procedure later on something like this so you see here you put the 200 tonnes and then that the displacement is increasing,

So what you will see is when you are doing unloading process if there is elastic part it will come back There is permanent deformation of the soil that will not come back that will be residual so it will keep on stacking up so that is what we are interested in Similarly we go to the 2nd 2nd step so when the 200 ton weight is placed on the cantalage,

When you relieved the hydraulic jack the load will go back to the support stock then put another 200-300 tonnes on top of it It will become 400 ton take the hydraulic jack and load it on to the pile and just repeat the procedure until you reach the total test load it could be ultimate test load or it could be working test load,

And every time you do this you will see a loading-unloading curve you can see so basically you will be taking this as a displacement 9 mm 8.5 mm for 200 tonnes so you can go and plot here load displacement in a different relationship,

And typically we will take several hours because get this flat curve sometimes you may have to wait longer time depending on type of soil if it is a sandy material you will get the displacement quickly after that it will just become flat If it is a clay it might take little bit longer time but then instead of setting this criteria IS codes actually gives the time to wait for one hour depending depending on  type of soil,

You may only vary little bit So if you look at the procedure given in IS codes it will give you the timing every time step how much time you need to wait and then start the process of loading-unloading In fact this this particular procedure is taken from pile testing manual which I was talking about day 1,

So the design specifications load all it is basically the test load if it is ultimate test design verification load will be your total load multiplied by the fact of safety 25 percent 50 percent 75 percent so this procedure is just segmented into 4 subdivisions 30 minutes so once you load 25 percent load wait for 30 minutes and 100 percent load wait for little longer time,

And then during the unloading process only because relieving of elastic compression will take just like this it is not going to take time so unloading time they are just allowing you to only little time 10 minutes And then again we start the process  100 percent and you are going to do a overloading test,

There you are going to wait for little longer time beyond the design verification load if it is a working load test and then repeat the procedure So basically this is just typical time versus increment of load,

I have just taken from the you know the manual of pile load testing from the Association of civil engineering contractors every everywhere they used this but if you look at the IS codes they may actually gives slightly different numbers and different timings,

You know so depending on which jurisdiction you want to use So if you look at this graph load displacement curve for ultimate load test up to failure So you can see depending on type of foundation material you will see 3 types of so if you look at the blue one N bearing and V crock basically it increases and then suddenly fails,

So you will see a certain capacity reaching the rock is trying to fail so almost like elastic and perfectly plastic so something similar like this And if you look at the black one friction pile in soft clay or sand you will see that highly nonlinear it keeps increasing and then the failure rate will be slow down achieving certain capacity,

Or else if you have a fiction pile in stiff clay also will be very similar but then there will be a downgrade effect because the stiff clay broke down when it is achieving the so typically you will see something similar when you plot the when you extract the displacement from  such plots,

Nowadays you can automate these kinds of things so automatically we will get a time bound graph then you can later take the displacement come up with the displacement versus the applied load graph is something like this and basically you need to decide,

Now what capacity is to be taken as ultimate or working load So depending on what the allowable all ultimate reflection that you want to permit remember when we were doing the TZ curve for clay and sand we were talking about 0.1 inch for sand and then 1 percent for clay something like this,

So that corresponds to the ultimate failure whether you want to consider here for steel piles has to be decided by what is your ultimate failure to state you want to define So once you define that limiting load or limiting displacement then you can go onto the graph you can take this is my ultimate failure load of the pile beyond which we will not be able to take it Saturday is the idea behind construction of this diagram is just to make sure that your TZ graph you have made is going to be reflected here,

And if you get a representative from here and that will be realistic because this is based on test where as the other one is based on historical data and empirical methods So you see here in this particular one the ultimate capacity at 25 mm settlement is taken as 425 tonnes,

So though it is highly nonlinear some amount of plastic deformation have happened compared to when you go to the blue if you look at it this is completely elastic and after that only becomes the plateau so you can see the difference So that is the way we want to determine,

When you do a testing I want to determine what is the ultimate capacity The thing is you have to sum up what is the displacement at which you would like to take for example when you are designing a structure you will always have a limiting deflection in both horizontal and vertical working load conditions,

So then if you are allowable capacity you want to find from this then suppose your fix rate 10mm is the allowable displacement during service life of the structure then 10 you just go to 10mm the pile has achieved a 350 tonnes,

Pile Load test

Now if you take the ultimate capacity apply a factor of safety of 3 or 2 you will only get something like 120 tons so that is what will be revealed here If you do not know about this graph is going what you are trying to do is if you take 420 tons join from here straight away to 0 make a straight line that is what you are doing by means of factor of safety 420 divided by factor of safety of 3 on load,

Whereas if you have this this graph you know very well that you can allow maximum of 10 mm during its service life with the factor or on factor load then you can decide how much margin you have almost large margin is available,

When you take 10 mm and restrict to 10 MM is the displacement 420 decided by factor of safety of 3 you will get around 130 tons that is what you are going to permit But actually the pile has got deserved capacity up to 350 at the same 10 MM displacement,

So that will be the difference when you have nonlinear load deflection curve especially after testing So this will give you a picture how much extra margin you have because of the soil behavior and if you take this one you will not get anything better is not it Because you are grabbing almost linear relationship,

If you take that will be the capacity of say 550 tonnes divided by straight away factor of safety of 3 you will get somewhere around 180 tonnes Whether it is 10 MM or 5 MM you are going to just linearly prorate so does not matter So that is the idea of constructing or establishing load displacement characteristics up to failure,

If we have only established up to for example some lower displacement because you are not going to do a failure test you are going to do a working load test just up to the linear portion then you may not actually reveal how the behavior after this this is why at least one or 2 piles at the site you have to do up to failure to see how much margin,

You have It can behave this way which we do not know unless you do the testing Then we also move onto horizontal load test basically similarly you can do horizontal load test One of the biggest problems is doing reaction she just now we have learned about vertical load test with support arrangement,

Somehow we can make it because it is similar piles can be driven but when you do horizontal load test you need to have some ground or firm support condition just to measure the horizontal displacement of the pile and also to transfer the reaction from the jacks which is going to be a big challenge So doing it onshore itself is a challenge,

Then when you are doing it in coastal or offshore conditions it is even a challenge because you have to design a system stronger than the test pile itself and install it And also you can carry out cycling load test in cases of coastal structures where cyclic behavior is required for degradation effects So typically you see here some working platform is required,

And I would have just straightaway gone to the coastal areas where some of the berthing structures we still do this lateral load test to establish the capacity in horizontal direction but most of the structure on land normally we do not do you know horizontal load test not really required,

Because predominantly it is not so much problem so far for buildings and bridges predominantly gravity load So you see here we have a test pile which is in yellow colour and we have a reaction pile and just the jack,

Now you see here the jack is placed in between attached to both the pile heads and the jack is trying to expand by giving horizontal load through the test pile the reaction is transferred to the reaction pile Noise they reaction pile stable the reaction pile displacement is smaller or ignoble then what you are measuring is the pile head displacement otherwise he will be measuring the relative displacement,

Because this pile is also moving the other pile also moving and how much we have to find out So you need a chili credit system to find out what will be the displacement which will be quite tough,

Because you can theoretically calculate but then it may not be correct A reference will be used another few numbers of piles is required or system is required to support all this as well as access to these places,

So you will see that horizontal load test becomes reasonably expensive because you have reaction frame and you also have a reference frame the reference frame the green colour what you see is a reference frame against which you will do the measurement of displacements,

And they are need to be placed sufficiently you know wider spacing otherwise what happens when you are doing when you are doing reaction here when the pile is trying to bend it puts undue pressure on the soil and that soil gets affected by this particular location and behavior of the lateral capacity is going to be affected to some extent and that is why you have to have minimum of 3 diameter or 4 diameter or 5 diameter,

Once it become wider spacing mounting of the jack becomes a problem you need to design a frame and that is going to put you onto support system together it has to be mounted onto the 2 piles which needs to be free to move so that is one of the challenge A typical cyclic load test results or plot how you carry out loading and unloading process basically horizontal load versus lateral load displacement,

You take it one cycle at particular load level bring it to 0 repeat it few times just to get the repeatability and again increase the higher load repeat it again load and unload since there is no dead weights are involved it is only hydraulic jack doing such load test is very easy then you repeat it again and again for various loads and stop,

When you actually reach the expected displacement for example ultimate load test you are trying to do for 100 mm maximum If you are doing a ultimate horizontal failure load test then you can go up to failure of the pile and stop otherwise you have a predetermined load by which it will not be a larger capacity,

Most of the pile if you look at 50 tonnes or maybe maximum 70-80 tons unlike the vertical capacity where you have thousands of tons or sometimes very large number Here it all be you know restricted by the pile horizontal shear because if the soil does not fail what will happen the pile will fail,

So if you look at the Shell capacity of the pile that will give you the maximum magnitude by which you can test in fact will apply factor of safety on it What you do not want you do not want the system to fail before the soil fails system means the pile itself or the anchor pile itself,

So you will find out what is the bending capacity of the pile or structural capacity and shear capacity Make sure that you have got sufficient factor of safety available on the structural system prior to go to ultimate load test,

Because you do not want the system to fail when there will be a catastrophe And in some cases in the coastal structures like berthing structures we may require pullout test because some of the piles are actually going to have tension capacity requirement especially when you build a berthing structure the front pile will be in tension the back pile will be in compression,

When you are having shift or berthing against the berthing structure So such you may require a pullout test instead of a compression test it is exactly opposite of it only the cantalage placement and the hydraulic jack placement is in the reverse condition,

If we just go back to our the this test somewhere here I think something like this so this this one is anchor pile method you are doing a compression test just reverse the process and placement of the hydraulic jack you will get the So basically the cantalage arrangement is attached to the reaction pile,

And there will be stress blocks and you have hydraulic jacks and then you attach your brackets welded to the test pile itself So what you are trying to do is you are compressing the reaction pile and pulling up the test pile so basically you are just reversing the reaction just to get what tension capacity is available Many times you will require this for coastal structures but magnitude will be not very big,

Few hundred tons So what are the things that we need to note down when you are doing a compression load test the support frame needs to be designed appropriately because you you have such a large weight to be placed Support piles needs to be placed away by 3 diameter that makes the so if you have 2 meter diameter pile you need to go for either side 3 meters 3 times 2 meters 6 meters so the frame becomes 12 by 12 or 15 by 15 Structural capacities of test pile,

As well as the support piles leads to be made sure that it has good adequate capacity Special care must be given to the test pile because it is a cantilever whereas actually the same pile when it is working in the actual structural system it may not be a cantilever it may be combined pile heads with the other structures,

Whereas when you are doing testing it is a pure cantilever you must remember what is the difference between pile in a temporary condition which is a cantilever to a supported pile in the permanent condition because of high level buckling The load capacity will come down drastically,

So you cannot think about always you have pile 1 meter diameter in a permanent system which is connected to a bigger structure which may not behave as a pure cantilever so the effective length and the conditions are different you are 1 meter diameter pile may work there whereas the same 1 meter diameter pile,

When you bring to the test category it becomes a pure cantilever number 1 high-level buckling load will be definitely half or less than the actual buckling capacity When you are doing the same ultimate load test here you do not want the pile to fail So what we really need to do is keep the diameter same because you need you do not want to change the pile-soil interface is not it Because we want to test the 1 meter diameter,

But what you can do is you can increase the wall thickness to increase the bending stiffness buckling capacity shear capacity in such a way that structure does not fail but the soil pile interface is being tested,

You understand the idea know so you need to make sure this otherwise if you bring the same pile and testing before the soil fails the pile collapses and then it puts the whole system into problem that is what you have to make sure So what IS codes are suggesting instead of what we saw was 25, 50, 75 they have divided into 5 sub-segments of loading 20, 40,60.80 to 100 so it is just a little difference,

And basically loading-unloading cycles almost similar I am not very sure whether I have copied the time cycle You can look at the code the time is also given 30 minutes up to 6 hours so you can refer to the code but what the criteria,

I wanted to look at it is basically when do we decide it has achieved its ultimate capacity and it is applicable only for concrete piles you cannot apply this one to steel tubular piles uhh it is not under that particular code So if you look at this graph,

I have just plotted one of the recent last year test two thirds of final load at which the total displacement attains value of 12 MM So you just look at the graph and just go around apply the criterion number 1 the safe load on a single pile for initial test should be least of the following,

So the criteria is given Do the testing comeback here plot the graph and look at these criteria whichever is lower that is your safe working load so that is the criteria that you are going to apply And of course this is written on the basis of onshore structures you know 2911 is a code for both the concrete piles for onshore applications not even for coastal applications that is why you cannot blindly apply this principle to a coastal structure on or offshore structure where displacement get area are different from dawn show structures,

You will see that they are very strict in terms of displacement because these are applicable to buildings and bridges or to some extent industrial structures on land where they are controlled by deflection Whereas if you go to coastal structures and offshore structures the displacement are definitely going to be larger,

You cannot even think of the criteria here because here they are talking about 25 MM When you think about coastal or offshore structure you are going to have several hundred millimetres of displacement because of the the magnitude of horizontal load you have to be a bit cautious and apply the principle differently 50 percent of final load at which the total displacement equal to 10 percent of the pile diameter,

So these are the 2 criteria so if you see there the criteria 1 and criteria 2 you can find out whichever is giving you the capacity I think even the lateral load also similar crater is given 50 percent of the final load at which the total displacement increases to 12 MM final load at which the total displacement corresponds to 5 MM and then any load corresponds to any specified displacement this is some at least some option is given for horizontal load,

So according to your project specific requirement so you specify I can go out to 50mm then I can look at so that if that is the thing that we need to have a decision-making process just doing load test alone will not be good enough you do not know what to do with that what you need is the demarcation what will be the acceptable displacement for that particular type of structure and applicable code in force,

What the API says we do not have a procedure to restrict the displacement unfortunately there is no requirement because we do not need because offshore structures are subjected to so much higher loading that if you restrict 25 mm displacement for example your structure will be so much bigger and may not be practical,

So that is why the the adapted method by API is to design by the factor of safety which gives you an adequate safety against pile failure or premature failure and at the same time you have a ductile material which is steel,

And you are not worried about failure by other means of fracture because the worry in concrete structure is larger displacement either in vertical direction or in horizontal direction can cause superstructure failure by fracture because the concrete cannot fail by the tail,

So that is one of the reasons why most of these concrete cores they restrict the displacement to smaller where as the offshore structures we never build using it except the concrete gravity platforms all the fixture types of structures are built by steel material has higher tensile capacity and also have a ductile characteristics In that reason we go by the method of engineering-based design based on soil properties with adequate factor of safety and we leave that we do not want to apply the restricting displacement,

The reason why we developed TZ all that is to make sure that pile is actually subjected to the actual load load displacement behavior and the bending stresses are calculated So if we have a larger displacement what happens is the pile is subjected to larger bending and larger bending means the requirement of section and the diameter and the thicknesses are going to increase,

So you design for it rather than trying to limit the displacement of the pile to lower value and increase the larger diameter so that is exactly the the design method adapted by API so so far I do not think any problem with that idea One of the issues with concrete pile supporting concrete structure is the architecture and finishers,

And serviceability requirement that is why it restricts the displacement to a very small value in fact the reason why we restrict to 1 inch is because of that You know if you have the structural system capable of taking the architectural finishes and service functions will be seriously disturbed that is why buildings are designed for smaller displacement,

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STANDARD PROCTOR COMPACTION TEST

STANDARD PROCTOR COMPACTION TEST

STANDARD PROCTOR COMPACTION TEST
PROCTOR COMPACTION TEST


STANDARD PROCTOR COMPACTION TEST

hello, In this post we will be going over The Laboratory procedure is used for a standard Proctor compaction test this Post will demonstrate how to conduct a standard Proctor compaction test in accordance with ASTM (American Society for Testing and materials) specifications.


This test was developed to evaluate the level of compaction on field of compacted soils In the proctor compaction test the soil is compacted into a mould as specific energy ➵➵➟comparable to the energy used in the field the laboratory practice is performed at varying moisture contents to establish a dry density versus moisture content plot.


From this plot the maximum value not weight and optimum moisture content can be determined the practical application of this test in geotechnical engineering is for compacted specification of soils the maximum dry unit weight obtained from this test can be used to determine the relative compaction of soils in the field.

EQUIPMENT’S FOR PROCTOR COMPACTION TEST



The equipment required for the standard Proctor compaction test is➯


➱4-inch mould having
➱volume of one thirtieth of a cubic foot
➱collar,
➱standard Proctor compaction hammer measured weighing five-and-a-half pounds and dropping 12 inches to moisture content cans,
➱steel straight edge,
➱large mixing pan,
➱graduated cylinder capable of holding up to 250 millilitres
➱spray bottle,
➱metal spoon
➱knife we’ll also be needing
➱digital balance
➱oven for moisture content determination


In a sample extractor the soil that we will be performing the standard proctor compaction test on as a low clay silt obtained from the Mississippi River Valley the soil has been mechanically pulverized than air dried the lab documents pertaining to today’s lab can be found on blackboard the handout is posted there and is titled C 215 laboratory number five Proctor compaction testing in addition an ASTM standard pertaining to this lab is also posted ASTM the 46 98 pertains to practicum passion testing also available is today’s datasheet

PROCEDURE OF PROCTOR COMPACTION TEST



The proctor compaction test consists of mixing soil with water to a predetermined moisture content the soil water mixture is then compacted into a mold of a specific volume with a standardized energy at low moisture contents.inter-particle friction will hinder compaction resulting in a low unit weight as moisture increases the friction in between the particle reduces and the particles will compact into a more dense pattern.

STANDARD PROCTOR COMPACTION TEST
PROCTOR COMPACTION TEST





At past a certain moisture content notice the optimum moisture content water will start to take the place of dry soil particles and the dry unit weight will again go down by conducting several standard Proctor tests at varying moisture contents.


 This curve can be established in the maximum dry unit weight and corresponding moisture content can be determined to perform the proctor compaction test.


Start by weighing the empty Proctor mould without the collar, record the empty weight on your data sheet also weigh the two moisture content cups and record their weights as well, with a caliper record the dimensions of the mould so the volume can be calculated average three equally spaced diameter dimensions in three equally spaced Heights dimensions so that an accurate measurement of volume can be established way out approximately 2,000 grams of the provided air dried soil,


Now that we have our soil weighed out the desired amount of water to add to the soil must be determined the weight of the water that needs to be added to our soil can be determined from this equation,


The weight of the water equals the weight of the soil 2,000 grams in this case times the final moisture content minus the initial moisture content the final moisture content is the target moisture content which I have selected to be 15% the initial moisture content is all the water that is trapped inside the air dried soil,


This has been predetermined to be 2.5% with 2,000 grams of soil and initial moisture content of 2.5% in a target moisture content of 15% it can be determined that I need to add 250 grams of water to my soil or 250 millilitres obtain the correct amount of water from the tap and pour the water into the spray bottle using the spray bottle,


Add the water to the soil and start mixing it till it becomes a uniform color and consistency when all the water is gone and the soil soil has been mixed to an even and uniform consistency it is time to place the soil in the proctor compaction mold,


Start by placing the collar back on the proctor mould spoon enough soil into the mould that when compacted the soil mould will be filled approximately one-third of the height of the mould,


Now you want to place the mould on a hard surface such as a concrete floor and compact with the Proctor hammer compact the soil using the standard Proctor hammer use 25 blows spaced evenly throughout the layer for proper compaction,


After 25 blows take the mould back to the table scarify the surface and add more soil for the next lift scarify the surface of the first compacted layer with a spoon this will ensure that the second layer will bind to the first layer,


Well spoon enough soil into the mould so that when compacted approximately 2/3 of the height of the mould will be filled again take the mould to the concrete floor and compact it with the standard Proctor hammer,


The soil should fill the mould and extend past the top of the mould an eighth inch using the straight edge trim smooth the top of the soil mould using the leftover material fill any voids that might appear in the surface of the soil,


Remove all this loose soil around the mould and way the mould without the collar loosen the soil mould from the base with two hands carry the soil in the mould into the extractor and extract the soil from the mould,


Insert the soil and mold into the extruder with two hands carefully pick up the soil specimen and carried it into the other room,


After the sample has been extruded split the sample with your knife take samples from the top and the bottom and place them in the moisture cans,


For moisture content determination weigh the cans on the scale and record the weights place the cans in the oven in 24 hours ,remove the cans and record the dry weights the dry unit weight of the compacted soil specimen,


And the moisture content can be calculated from several iterations of this test a plot of the dry unit weight vs. moisture content can be determined from this plot the maximum dry unit weight and corresponding optimum moisture content can be determined .


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High Performance Concrete (HPC)

High Performance Concrete (HPC)

High Performance Concrete (HPC)
 

High-Performance Concrete (HPC)

➤ The Performance Requirements of Hardened concrete or high-performance concrete are more or less well defined With respect to Shape, finish, strength, durability, shrinkage, and creep,
➤To achieve these objectives economically, the fresh concrete in addition to having a suitable composition in terms of quality and quantity of the materials should satisfy a number of requirements from the mixing stage till it is transported, placed in a framework and compacted,
 

Definition of high performance concrete➤

➤ High-performance concrete (HPC) can be defined as concrete that possesses high strength, work-ability, density, low permeability and resistance to chemical attack,
HPC is concrete that has been designed to be more durable and if necessary stronger than conventional concrete,
 

Introduction of high performance concrete➤

➤Deterioration, long term poor performance, and inadequate resistance to hostile environment led to the accelerated research into microstructure of concrete and hence the evaluation of high-performance concrete,
➤ Long-term performance of structures has become vital to the economics of a nation,
➤As a result, new materials and composites have been developed,
➤Today concrete structures with high compressive strength of 140 MPa are being built in United States and Europe,
 

Benefits for the designer➤

➤ The benefits of high-performance concrete to the designers are much more than those of high-strength concrete,
➤Designers can design smaller cross-sections,
➤Slender members,
➤High Elastic modulus,
➤Initial high early strength,
➤Rapid attainment of final creep level,
 

Benefits for the producer of high-performance concrete➤

 
➤In the Production of high-performance concrete Quality control in terms of raw materials and finished products is imperative,
➤Increased quality control leads to increased profitability and productivity of usual concrete,
How is high-performance concrete made?

Mechanism of high performance concrete➤

Under compressive loads, failure in normal concrete occurs either➯
 
➱Within the hydrated cement paste,
➱Along the interface between the cement paste and aggregate particle,
➱Aggregate,
 
To improve the strength and other properties it is necessary to strengthen these weak areas,
 

Improving the strength of hydrated cement paste can be done by➮ 

➤Reducing the water binder ratio and hence the usage of super plasticizing admixtures having high range water reduction capacity,
➤Using supplementary Cementitious materials,
 

Increasing the strength of the transition zone➮

➤Reducing water and cement ratio.
➤Using supplementary cementitious materials.
➤Ensuring proper coating of aggregates with cement paste.
➤Use of smaller-sized aggregates leads to homogeneous distribution of water.
 

 Aggregate Failure➱

➤Due to Aggregates failure Cement paste material remains intact.
➤Failure plane propagates through the Coarse aggregate particles.
 
What are the two typical ingredients used in high performance concrete?

Ingredients of High performance concrete➤

➤Cement (O.P.C, blended Cements etc.)
➤Water,
➤Aggregates
➮Fine Aggregates
➮Coarse Aggregates
➤Admixtures
➤Supplementary Cementitious materials(Fly Ash, Silica fume, GGBS, etc.)
 

Cement➱

Cement Selection is critical to rheology and compressive strength.
 
➤Fineness of Cement
 
➮ From the Strength point of view, the finer the cement the better the concrete,
➮ From the Rheological point of view, The finer the cement the more reactive concrete,
 

Water➱

➱Chilled water is added to reduce the concrete temperature,
➱ice flakes are added as a part of mixing water,
 

Aggregate➱ 

Strength of aggregate depends on the nature of the parent rock Prepared from.
 
➱Avoid rocks with weak cleavage planes of severely weathered.
➱Fine aggregates should be rounded and uniformly graded.
 

Admixtures➱

Super plasticiser➮ 
 
➱Disperses Cement Particles within the mix.
➱Reduces the Amount of mixed water.
➱Controls the rheology of very low water/binder ratio mixtures.
➱solve slump loss problems.

Supplementary Cementitious materials➱

➱Ground Granulated blast-furnace slag.
➱Fly ash (low Calcium, high calcium).
➱Silica flume or micro silica.
➱ Natural pozzolana (meta kaolin, rice husk ash).
 

Aspects of High-performance concrete in fresh state➱

➱Batching and mixing.
➱Tests in fresh HPC concrete.
➱Placement and Compaction.
 

Batching and Mixing➱

➱Batching of individual materials must be accurate.
➱Longer mixing time is required to ensure homogeneity as the mix is usually sticky.
➱Mixing time of 90 seconds is recommended.
 

Tests on Fresh HPC Concrete➱

Following tests on fresh high-performance concrete is carried out.
 
➱Slump / Flow table 
➱Air content 
➱Temperature
➱Unit weight
➱Setting time of mix
➱Bleeding
➱Slump retention and Pump-ability 
 

Placement and compaction of High performance concrete➱

➱Concrete mix is carried from the batching plant with the help of transit mixtures.
➱Method of placing is mostly by pumping.
➱Compaction is by both External as well as internal means.
 

Test on Hardened high performance concrete➱

The following tests are carried out on hardened high-performance concrete.
 
➱Compressive strength (Cube and Cylinder)
➱Split Tensile strength.
➱Modulus of elasticity.
➱Water permeability.
➱Rapid Chloride penetration test(RCPT)
 

Durability of HPC➱

➱Durability of Concrete can be defined as the resistance of concrete to deteriorating influences which may be inside the concrete itself or which may be present in the environment to which it is exposed.
➱ The durability of Concrete Largely depends on the ease with which fluids, both liquids and gases, can enter into and move through the concrete. This property is known as the permeability of concrete.
High Performance Concrete (HPC)

The durability of HPC: Carbonation➱                                          ͏͏͏

➱ In Presence of Moisture CO2 Present in Air reacts with Ca(OH)2  to form CaCO3.
➱ Carbonation causes the reduction in pH of pore water from between 12.6 to 13.5 to about 9.
➱ Steel embedded in concrete forms a thin passivity layer of oxide which remains only with high pH.
➱ As The pH reduces the oxide layer is removed and the corrosion of steel starts, its volume increases and creates tensile stresses in concrete.

Durability of HPC: Chloride attack➱

➱ The primary action in chloride attack is the corrosion of steel and consequently damage to surrounding concrete.
➱ As long as the oxide film on steel is present, The steel remains intact.
➱ Chloride ions destroy the film and in the presence of water and oxygen corrosion occurs.
➱ Corrosion does not occur in dry or fully submerged concrete but occurs in alternate wetting and drying and relative humidity of 70-80 %.
➱ Chlorides can be present in concrete through the use of contaminated aggregates, seawater or chlorides in admixture.
➱ According to I.S.  total chloride content in cement should not exceed 0.05% by mass of cement.
➱ I.S. 456-2000 states that total Chloride content in concrete should not exceed .4 and .6 kg/cum for pre-stressed and reinforced/plain concrete containing embedded metal respectively.
High Performance Concrete (HPC)

Durability of HPC: Sulphate attack➱ 

➱ Common sulphates present in soil and groundwater are sodium, potassium, magnesium, and calcium.
➱ Sulphates present in solution react with hydrated cement paste.
➱ Sodium sulphate attacks Ca(OH)2 and gypsum is deposited, Ca(OH)2 Can Also be completely leached out.
➱ Magnesium sulphate attacks calcium silicate, calcium aluminate hydrates and also Ca(OH)2.
➱ Calcium sulphate attacks calcium aluminate hydrate (C3A) forming ettringite.
➱ Ettringnite formed has a higher volume and causes expansion in concrete.

Durability of HPC: Alkali Aggregate Reactivity➱

➱ Reaction between active silica constituents of aggregates and alkali in cement forms alkali-silicate gels in planes of weakness or either in pores or surface of aggregates.
➱ The reaction starts with an attack on siliceous minerals in aggregates by alkaline hydroxide in pore water derived from the alkalies(Na2O or K2O) in cement.
➱This gel is of unlimited swelling type, absorbs water and causes an increase in volume.
High Performance Concrete (HPC)

Development Of HPC Mixes➱ 

➱ Computing the Target strength.
➱ Estimating mixing water content.
➱ Calculation of water to cementitious material ratio.
➱ Selection of percentage of SCM.
➱ Selection of fine to total aggregate ratio.
➱ Calculation of aggregate contents.
➱ Selection of Superplasticiser dosage.
➱ Trial mix and testing.

Development Of HPC Mixes with Fly Ash➱

Approx mixing water for 20 mm aggregate and 100 mm slump

Fly Ash Content  Water kg/Cum
30 155+5 or 155-5
40 150+5 or 150-5
50 145+5 or 145-5
 
➱ Selection of fine to total aggregate – Normally 25-40 % is used depending upon the grade of concrete, nominal size of aggregate and workability required.
➱ Calculate aggregate content based on the absolute volume method.
High Performance Concrete (HPC)
 
High Performance Concrete (HPC)
 

Where is high performance concrete used?
What is high performance concrete used for?

All Necessary Factors➱

 
Specifications for Bandra – Warli Sea Link Project➱
 
 ➱ Selection of water/binder ratio sufficient enough to achieve the target strength with special consideration from a durability point of view.
➱ Use of Supplementary Cementitious material together with a low water to binder ratio to make concrete structure more dense with a minimum volume of capillary pores, hence making it more durable.
➱ Water content in the mix is required to be kept at the lowest practical so as to minimize drying Shrinkage.
➱ Limiting the heat generation (especially in mass concrete) by keeping the total OPC content in the mix to the minimum required.
➱ Use of high-range water reduction admixtures to achieve the required workability.
High Performance Concrete (HPC)
Bandra-Warli Sea link under construction
High Performance Concrete (HPC)
bandra-Warli Sea link

Project Specification➯

Grade of Concrete- M60
Target Strength – 74 MPa
Max.Water / Binder ratio – < .35
Permeability – Less than 25 mm as per DIN 1048

Ingredients (Kg/cum) Earlier Mix Modified mix
Cement  320 300
Fly ash  110 (25 %) 196 (40 %)
Micro silica 43 40
Total cementitious material  473 536
total water  127 136
W/C ratio  .27 .25
Coarse aggregate  947 1077
fine aggregate 947 750
Admixture 15.1 10.9
 
Properties  Earlier Mix Modified Mix % (Modified/Earlier)
Compressive Strength (MPa)
3 days 39.8 39.3 98.7 %
7 days 56.9 54.8 96.3 %
28 days 78.1 74.7 95.6 %
56 days 79.4 80.9 101.9 %
91 days 80.9 92.2 113.9 %
 
Durability properties  Field results
Water Permeability @ 28 days NIL
RCPT @ 28 days 657 Coulombs
RCPT @ 91 days 432 Coulombs
 
High Performance Concrete (HPC)
 
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