Handbook Foundation Form Work Rebar Concrete

7/18/2019 Handbook Foundation Form Work Rebar Concrete

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Hand Book on Foundation,Formwork, Rebar &Concrete

Building Structure

Competency Center


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PREFACE

Construction industry in India is growing at faster pace

and the Buildings & Factories Operating Company (B&F

OC) is no exception in terms of number, size and volume

of projects. This growth throws challenges in terms of

delivery without compromising on Quality, Safety and

Sustainability. To meet this challenge, human resource is

the prime mover and it is essential to upgrade the skill and

knowledge level of engineers and front line supervisors to

the latest technology that our company adopts to sustain our leadership in the

market.B&F OCs entire business is grouped into three disciplines namely Structure,

Finishes and MEP. Building Structure Competency Cell (BSCC) of B&F OC

is created to provide total solutions to structure discipline in the areas of

Foundation, Formwork, reinforcement, Concrete and Pre-stressing.

BSCC has come out with a reference hand book on the methods and processes

adopted in construction of structure. I have gone through the book and found

it very useful for site engineers especially inUnderstanding the basics

Application in respective field

DOs & DONTs

Specifications & Standards

With this handbook they will be able to largely address the day to day issues

that they face and thereby become self-sufficient.

I am sure that the BSCC site engineers and Supervisors will make use of this

hand book to improve the operational efficiency which should translate into

improved quality at optimum cost.

I appreciate the entire BSCC teams who have put inefforts to make this book

a comprehensive tool.

(A.L.Sekar)

Vice President & Head RBBU.


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INDEXCONTENTS Page No.

ALUMINIUM FORM WORK

Introduction ...........................................................................................6Worksite Management ...........................................................................6

Assembly & Dismantling Process .............................................................9

Flowchart for Aluform ..........................................................................32

SLIP FORM

Introduction .........................................................................................34

Type of Slipform ...................................................................................36Assembly procedures ...........................................................................36

Tapering Slipform ................................................................................38

Assembly of stair tower .........................................................................39

Dismantling procedure .........................................................................40

Summary of Labour Productivity Norms .................................................43

Slipform Planning ................................................................................44

TUNNEL FORM

Aluminium Formwork Refurbishment .....................................................47

Plywood ..............................................................................................71

Form Release agent .............................................................................73

Formwork lift .......................................................................................74

Automatic Climbing System ..................................................................75

Hand tools required .............................................................................76

Guidelines for Formwork Engineer .......................................................33

Guidelines for Foreman/Charge hand ..................................................78

System Formwork Functions, applications& Safety. .................................79

REINFORCEMENT WORKS

Category of Reinforcements ..................................................................91Reference Indian standards ..................................................................91

Reference International Standards .........................................................91


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Hook & Bend Allowance .......................................................................92

Bar bending Schedule Format ...............................................................93

Minimum diameter required for Bending Former ...................................98

Cross-sectional area & Mass of Rebar ...................................................99

Checks ..............................................................................................100

Testing of Rebar .................................................................................101

Nominal cover ...................................................................................104

Tips on Cover ....................................................................................104

Tolerance of cover ..............................................................................104

Material for cover ..............................................................................105

Photographs (Rebar) ..........................................................................106Prefabricated cage photos ..................................................................109

Rebar tying machine ..........................................................................109

Splicing methods ...............................................................................110

Precautions ........................................................................................110

Splicing strengths ...............................................................................110

Reinforcement couplers ......................................................................110

Coupler photographs .........................................................................111Classification of test for Reinforcement couplers ...................................112

Reinforcement Binding .......................................................................113

Welding of Reinforcements .................................................................115

Precautions in Rebar activity ................................................................117

PILNG WORKS

Pile ...................................................................................................119

Classification .....................................................................................120

Factor governing Pile selection ............................................................112

List of Reference Codes ......................................................................125

Installation sequence

Driven cast in-situ piles ..................................................................126

Bore cast in-situ piles .....................................................................127

Characteristics of Bentonite suspension for BCIS piles ..........................128

Important things to be followed ..........................................................130


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Driven cast in-situ piles ..................................................................130

Bore cast in-situ piles .....................................................................131

Driven precast...............................................................................132

Load test on Piles ...............................................................................134

Types of Arrangements .......................................................................134

Vertical load test Arrangements ......................................................135

Lateral load test Arrangements ......................................................137

Pullout test arrangements ..............................................................138

Pile Integrity test .................................................................................140

PDA Test ............................................................................................140

O Cell Test. ......................................................................................142

CONCRETE WORKS

Cement .............................................................................................145

Physical requirement of Cement ..........................................................149

Mineral Admixtures ............................................................................150

Fly ash .........................................................................................150

GGBFS .........................................................................................154Micro silica& Metakoline ................................................................154

Aggregates ........................................................................................155

Mechanical Properties ...................................................................158

Grading Requirements ..................................................................159

Mixing of water ..................................................................................161

Admixture ..........................................................................................162

Concrete ...........................................................................................163

Grades of concrete .......................................................................164

Exposure conditions ......................................................................165

Batching ............................................................................................168

Mixing Time .......................................................................................170

Transporting Concrete ........................................................................171

Planning ............................................................................................172

Compaction ......................................................................................173

Vibration ...........................................................................................173


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Points to remembered in Compaction .................................................174

Finishing ...........................................................................................175

Curing ..............................................................................................177

Common defects in Concrete .............................................................179

Types of Surface defects ......................................................................180

Special concrete .................................................................................186

PRESTRESSING

Introduction .......................................................................................187

Definition ..........................................................................................187

Advantages of Prestressing .................................................................188Application ........................................................................................188

Materials management ......................................................................189

Reference Standard & codes ...............................................................191

Elongation & Modified Elongation Calculations ...................................192

Jack Pressure calculations ...................................................................192

Losses in Prestressing .........................................................................193

Properties of HT strand (IS: 14268-1995) ............................................193Methodology of Post Tensioning works ................................................194

Prestressing Equipments. ....................................................................197

Tendon Profile ....................................................................................198

Case study ........................................................................................199

Photos. ..............................................................................................201


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Introduction

Formwork Drawings

Site will be provided with a set of formwork drawings which entailed the

followings: -

Shell Plan Layout

Formwork layout drawings,

Wall panel Layout,

Slab Panel Layout,

Starter Block Layout,

Corner Layouts,

Beam Panel Layout,

Soffit Layout,

Staircase Layout,

Bracket and Soldier layout,

Miscellaneous Layout which includes sunken portion, upstand portion

etc,

Elevations and sections drawings indicating the location of formwork

panels and component,

Typical Fixing Detail drawings,

Location of Box outs and Transfer Box out drawings for transfer of

Formwork, etc.

Worksite Management

Logistic

Prior to the arrival of the containers from the disembarking point to the

project work site; a Stock Yard is to be properly allocated and set up for

the unloading of the formwork material and accessories.

This Stock Yard should preferably be located at close proximity or within

the compound of the project work site, properly fenced up and security

Aluminium Formwork


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shall be of up most priority due to the high residue value in the secondary

market for aluminum formwork material.

A Workshop area for maintenance of formwork material is recommended

to be set up at the project site to minimize the downtime in requisition of

replacement panels.

The proposed Stock Yard and Workshop area shall be flexible and re-

adjustable to suit the working environment and project work site. As a

result of the far away Stock Yard or Workshop area the project progress

will affect the targeted construction cycle time. (Ref Layout Drg No.: )

Upon arrival of formwork panels at Project Site, Site personnel shall ensure

that the panels are stacked and stored according to sizes and marking using

proper separator such as pallets for easy identification and allocation for

subsequent distribution. (Dry Mockup will be assembled as per schemes

at factory; this will eliminate the usual problematic discrepancies of odd

size panels which need to be fabricated at project site).

Manpower

BSCC - HQ shall provide the estimated manpower requirement for the

Project based on the quantity of formwork panels to be supplied to achieve

the required cycle time. This manpower requirement shall vary according

to the size of formwork use on the building.

However, the manpower requirement for other supplementary trades which

complement the formwork installation such as Mechanical & Electrical

(M&E) services and rebar works need to be taken into consideration also.

A joint effort of all operations from formwork installer, rebar, plumbing,

electrical and concreting workers need to be synchronized to achieve therequired cycle time.

Segregation and systematically allocation of duties for each formwork team

are required in ensuring optimization of productivity. Hence, each team

shall be delegated or assigned to do specific job tasks on a daily basis to

resemble a manufacturing production line. However, due consideration

should be used in determining the level of experience and compatibility of

persons when allocating tasks to minimize the risks.


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Safety

Control measures should be taken to identify and minimize the hazards

associated with work involving the assembly and dismantling of formwork

equipment such as falls from height, slips, falling objects, noise, dust and

manual tasks.

The external working brackets/platforms or scaffoldings should not be

used to stack materials or equipment. This will lead to the persons working

on it expose to additional hazards in relation to trips and slips or collapse

of the external working brackets / platforms or scaffolding.

Minimize the working heights for persons performing the assembly and

dismantling formwork.

Mixing of formwork components should be avoided to prevent unsafe

installation such as mixing pins and braces which may lead to collapse of

the formwork.

Do not allow drop stripping of formwork as it is an unsafe practice.

Partially assembled or dismantled formwork should be secured during

break time to prevent against overturning or collapsing due to strong wind

or accidentally / unintentionally knock over by workers.

Electrical safety should be implemented for the safe use of electrical

equipment.

Protruding flat ties or projecting nails should be removed immediately

with appropriate tools at dismantling stage.

Use of personal protective equipment by all persons working at work

areas (such as safety hardness, safety helmets, eye protection etc) should

be strictly implemented.

Accessories & Tools

Accessories (10%) extra will be supplied for the assembly and dismantling

of the formwork panels.

Sufficient tools required for assembling and dismantling will also be

supplied as per the attached list.


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Setting Up Level & Marking Of PositionThe project surveyor shall mark based on the approved construction drawings

to ensure that the gridline and level of the foundation level is properly set up,

marked for walls, column etc. Leveling must be checked prior to commencement

of formwork installation to ensure accurate positioning.

Formwork Panels

Cleaning of the surface and side panel of the formwork after each usage

shall be done immediately using proper tools.

Ensure that all front and side panel of formwork is properly coated with

recommended Form release agent that prevents from sticking and concrete

buildup aluminium form surfaces. It protects and prolongs the useful lives

of the aluminium formwork.

The following precautions shall be taken when applying the Formoil on

the aluminium panels.

The best results are obtained when a uniform application of Formoil is

applied immediately following stripping and subsequent cleaning of

the panels. Always ensure that the coated form surfaces are allowed

to dry prior to placing concrete.

Do not over apply. Excess Formoil can adversely affect performance

and should be picked up promptly with rags.

Prevent Formoil overspray from contacting reinforcing steel bars and/

or tensioning cables.

Installation Works of Rebar, M&E & Plumbing

The support works such as rebar, Mechanical & Electrical (M&E) and

plumbing are to commence immediately once the set up is done. The

same is to be ensured before installing the Aluminium formwork.

The support works for the slab section commence after the slab formwork

panels are assembled.

Cover Blocks should be fixed on both sides of the rebar section for

positioning and eliminate the rebar from resting on the surface of the

formwork panels.

Assembly Process


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Positioning of outlets for electrical switch boxes to its correct alignment can

be done by riveting the appropriate fit size mould to the formwork panels.

The electrical switch boxes are then securely cap to the fit size mould and

fasten by way of wiring to the formwork panels. Ensure that it is properly

secured to prevent grouting from building up in the switch boxes.

Assembly of Wall Formworks

Always commence wall erection from the external corner of the wall

section to ensure both joint external corner wall panels will support each

other for standing position. Pin and wedges are to be used to secure the

panels together. Always insert the pin from the inside out for easy removal

of pin after concreting.

The formwork panels wall positioning is securely placed on the marked

gridlines and level by way of fixing timber stoppers at the base of the

outer side of the formwork panels at interval of one (1) meter. This would

ensure that the formwork panels are not disposition during the concreting

process.

Once the initial wall corner panels are assembled, place the wall corner

panels on the allotted set up position.

Commence to erect simultaneously the balance of the wall panels from

either side of the external wall panel.

Proceed to assemble the internal wall corner. Place these panels into the

correct position on the lines which were set up by the surveyor. Proceed to

assemble the balance of the internal wall at both sides.

The internal and external walls are to be held together by flat wall tie with

wall tie sleeve and PVC cover. These wall tie sleeve and PVC cover are

to be cut for the exact length of the wall thickness. Flat wall tie are to be

coated with the Form Oil before each usage.

To determine and achieve the vertical accuracy of the formwork panels

assembled before concreting process, several methods such as plumb

bob, spirit level, theodolite equipment etc can be used. The simplified

method of using a plumb bob with a string attached to it which is then

suspended from the upper part of the formwork panels is used as a guide

to determine the deviation from the vertical alignment of the panels.

Additional wall panels or starter blocks (kickers) are fixed on the external

wall panels in accordance to the required height for the formation of the


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slab concrete. Check to ensure that the verticality of the Starter Blocks

(kickers) is correctly aligned.

The Starter Blocks (kickers) shall remain at its position for the subsequent

forming of next level wall.

Assembly of Beam & Slab Formworks

Fix the slab corner on top of the wall panels with round pins and wedges.

The position of the pins should be from top down to ease the dislodging

process.

The prop length and prop head is to be connected together for beam and

slab support.

Alu span mid beam and Alu span cantilever end beam are connected to

the Slab prop head using Beam Splice Bars. They are connected together

by long pins and wedges at bottom section.

The Aluspan mid beam sections are accurately position to enable the slab

panels to be connected systematically.

Commence to assemble the slab panels from the corner section of the

slab. Subsequently, fixed the whole slab area by pinning the slab panels

together with the Aluspan mid beam.

Assembly of External Working Brackets

External working platform brackets are used to provide a work area at the

external wall section.

Once the first level is completed and external formwork panels are

removed, fix the external working brackets to the first floor level at position

slightly below the kickers which are fixed on first floor external slab.The external working brackets are secured to the external wall section

from the inside using tie rods, nuts and bolts.

Once all the external working brackets are put in place, timber planks

and strips are placed on the floors and railings respectively to create an

external working platform for the assembly of the subsequent level of the

external formwork panels and kickers.

Another set of external working brackets are later fixed on the subsequentlevel using the method as prescribed above.

Once the subsequent level of external formwork panels are fixed, the


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external working brackets at one level below are removed and moved to

the subsequent level. This process is repeated until the completion of the

subsequent floors.

Identification of Formwork Assembled

A numbering sequence / stenciling shall be given for each panel and is

identified in accordance to unit area such as living rooms, Kitchens, Bed

rooms, bathrooms, common areas etc.

Color identification scheme while numbering on each section or area will

also eliminate the confusion that may arise due to the size. It can be

identified such that Blue is for Room 1, Red is for Room 2, Green is for

Living area etc.,

By practicing the use of numbering system in combination with the color

identification scheme, it have been proven to avoid confusion and assist

in the process of identification of panels position once they are transferred

to the next level/floor.

CONCRETING PROCESS

Pre-Check Before Concreting

Ensure that the position of the walls and column formwork are in

accordance with the set up marking.

Check to ensure correct spacing of props for slab formwork.

Check the verticality and horizontality level of the wall and slab panels

respectively.

Ensure that all pins, wedges and ties are properly secured and tightened.

Re-check the opening such as door and window panels are correct.

Re-check all propping stands to ensure its height are in accordance to

drawings.

Adequate bracing (if necessary) to ensure stability.

Ensure cover blocks are placed correctly.

Monitoring During Concreting Process

Ensure site coordinators are available and on stand-by during the

concreting process.

Always ensure that concrete pouring is distributed evenly throughout the


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wall sections before commencing to cast the slab level areas. This is to

prevent loading pressure on the formwork panels due to uneven casting.

Recheck the areas whenever cement slurry leakage is noted to determine

the cause of it. Remedy work should be done immediately to ensure the

concreting process is not affected.

During concreting, always ensure that immediate step is taken to remove

/ clean all the excess concrete that is stuck on the back of the formwork

panels. Non removal will result in the formwork panels getting too heavy

and also the scrapping task after the concrete has dried up becomes more

tedious.


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Dismantling of Wall, Column & Beam Formwork

Formwork panels shall be removed without damaging the concrete.

Reinforcement Bars or other tools shall not be used as a lever against the

concrete in removing the formwork panels. Only panel puller shall be

used for removing the wall panels.

The appropriate time for the stripping of formwork panels will vary

according to the environment and type of concrete used. The formwork

panels of the wall, column and beam section can be usually dismantled

after 12 hours. However, this process shall subject to approval of theproject structural engineer after taking into consideration the grade of

concrete used, additional props stand ordered, etc.

Always ensure that the wall section panels are removed first follow by the

column and beam sections.

For precautionary step, ensure that formwork panels are removed

systematically and due care is to be taken to prevent any damages to the

formwork panels and also finish surface of the concrete whenever possible.

For safety reason, ensure that no workers are facing the pin and wedges

when removing using hammer. Pin and wedges removed are to be

collected and placed in containers to minimize lost and replacement.

The dismantle formwork panels shall be transferred to the next level/floor

for subsequent assembly process via the slab opening or staircase areas

in an orderly manner and to the appropriate section/area immediately.

This will eliminate the confusion and congestion in the dismantling area

or level as a result of too many dismantled formwork panels lying on the

floor area.

As the formwork panels are pre-numbered and if color identification

scheme is implemented, the transfer of panels can be determined and

planned ahead according to the various sections / areas of one level/floor

to the subsequent level/floor.

Always ensure that all the formwork panels are to be properly cleaned

and applied with the Form release agent to protect the surface of the

formworks before re-used.

Dismantling Process


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For the external wall section, the Starter Blocks (kickers) on the upper

portion of the floor level shall remain intact to support and align the

next level/floor of formwork panels that are going to be assembled.

The assembly of the external formwork panels can be done by using the

external working platforms that are fixed to the wall areas.

Dismantling of Slab Formwork

The appropriate time for the stripping of formwork panels will vary

according to the environment and type of concrete used. The formwork

panels of the slabs section are usually dismantled after 36 hours. However,

this process shall subject to approval of the project structural engineer

after taking into consideration the grade of concrete used, additionalprops stand ordered, etc.

The Aluspans mid beams / end beams have to be removed first after

dismantling the wall panels. Proceed by removing the long pins and

wedges on the joint bars for the end and middle beams. However, the

prop lengths are to remain undisturbed during this process to lend support

for the weight of the concrete slab.

There shall be 2 sets of prop lengths to support the concrete slab. The firstset of the prop stands will only be removed when the assembly of the third

level/floor commences and also upon approval and consultation with the

project structural engineer.

Proceed t o dismantle the slab panels by commencing from the end of the

slab area. Once the slab panels are dismantled, continue to remove the

slab corners.

Removal of Flat Wall Tie & Wall Tie Sleeve

Flat wall Ties are used for the purpose of ensuring the thickness of the walls

and column are consistent. Flat wall ties are to be removed by using special

called Wall tie remover / extractor.

Subsequently, proceed to remove the wall tie sleeve which is embedded in the

walls and columns section by using nose player.


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Sequence No. 1

Form Release agent (Solvent based) to be applied on the surface of all thepanels before the assembly process.

Assembly Process


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Sequence No. 2

Outer Corner is fixed to External Wall Corner panel by round pin andwedge.

Assembly Process


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Sequence No. 3

Inner Corner is fixed to the Internal Wall panels by round pin & wedge. TheInternal and External Wall Panels are hold by Flat Tie with Tie Bar Shield in

between the panels.

Assembly Process

VERTICAL CORNER INTERNAL


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Sequence No. 4

Repeat Sequence No. 3 to complete the assembly of both the Internal andExternal Wall Panels.

Assembly Process


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Sequence No. 5

Install Slab Corner on the top portion of the Wall Panels with round pin &wedge.

Assembly Process

Slab Corner Internal


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Sequence No. 6

Aluspans mid beams / end beams and Prop head are combined by Beamsplice bar with long pin and wedge at the bottom section.

Assembly Process

BEAM SPLICE BAR

BEAM SPLICE BAR

Aluspan

Aluspan cantilever


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Sequence No. 7

Start the assembly of the Slab Panels from the Slab corner Internal.Subsequently, fill out the whole slab area by pinning the slab panels together

with the Aluspans (Comprises of Aluspans and cantilevers). Mid Beams / End

Beams

Assembly Process

Slab corner Internal


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Sequence No. 8

Additional Wall Panels (or Kickers) are fixed to the external Wall Panels to raiseto the appropriate height to contain the slab concrete when it is poured.

Assembly Process

ADDITIONAL WALL

PANEL / STARTER

BLOCK


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Sequence No. 9

Upon completion of the installation and fixing of the Wall and Slab Panels,a numbering sequence will be made for each of these panels with colour

identification scheme to differentiate each of the unit area such as bedrooms,

living room, bathroom etc. This numbering and colour identification scheme

will ensure that each panels can be determined as to their exact location once

they are tansferred to the next level for installation.

Sequence No. 10

Always ensure that wall ties, pins and wedges are properly installed and

secured before pouring concrete into the forms. Ensure that concrete pouring

is distribute evenly throughout the Wall Panels section before commencing tocast the slabs level area.

Assembly Process


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Sequence No. 1

After 12 hours, remove the Internal Wall panels by knocking out the wedgesand pins. The Wall Panels are to be moved to upper floor through the slab

opening as shown. The transferring of the panels should be done in a

systematically and orderly manner to ensure that the next cycle or level is not

affected. Since all the panels are numbered with different colour identification

scheme, these transfer process can be determined and planned in advance

according to section of the building such as Room 1, Room 2, Bathroom are

etc.

Dismantling Process


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Sequence No. 2

After removing the External Wall Forms (the starter Block (kicker) shouldremain undisturbed), the dismantled wall forms are moved to upper floor.

Access Scaffolding is use for transferring of external wall panels from the

ground floor level. For level 1 and above, an external working platform is

fixed to the external wall. The external wall forms from level 1onward shall

be supported by the kickers. (These steps are to be repeated from one floor

to another floor.)

Dismantling Process

Starter Block

Super plate


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Sequence No. 3

After removing the Wall Panels, proceed to the Slab Panels after 36 hoursby removing the long pins and wedges on the joint bars the end and middle

beam section.

Dismantling Process


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Sequence No. 4

Upon removing the Aluspans Mid Beams and Aluspan cantilevers End Beams,the prop shall remained undisturbed during this process to support the

concrete slab.

Dismantling Process


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Sequence No. 5

Proceed to strip the Slab Panels and transfer to the next level according to thedesignated area and installation sequence.

Dismantling Process


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Sequence No. 6

Strip the Slab Corner.

Dismantling Process


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Sequence No. 7

Pull out Wall flat Tie using Wall Tie puller and remove the Wall tie sleeve usingNose player.

Sequence No. 8

When the cube tests show that the slab concrete is sufficiently strong, the prop

together with the prop heads are removed and transferred to the next level.

Dismantling Process


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Flow Chart forAluform Work at Site

If not suitable

If suitable If not suitable

`

If work front is not ready

If work front is ready

1

2 3

4 4a

2a, 2b

5

6

7

8

7a

9

13

11

15 15a

16a

1a, 1b, 1c

3a

12

14

10

16

1919a, 19b, 19c, 19d

20212223

17 18


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Activity for the FlowChart Numbers

1. Receive Aluform materials.1a. Packing list, BOQ, and Formwork layout.1b. Tools.1c. Additional accessories.

2. Visual inspection.2a. Packing list & schemes.2b. Acceptance criteria.

3. Inform concern for any defects3a. Details of report.

4. Collect modification details.

4a. Fabrication drawings.5. Stock the material as per packing list.

6. Room wise segregation.

7. Dry mock-up.7a. Schemes.

8. Room wise numbering for identification.

9. Dismantling of mock-up.

10. Setting out.

11. Shift to work location.12. Shift to stock yard.

13. Actual assembly at work location.

14. Slab rebars & M&E works.

15. Final checking (Pre pour check)15a. Check list.

16. Concreting.16a. Pour card.

17. Post pour check.

18. Leveling and finishing.

19. De-shuttering19a. Removing pins and wedges.19b. Removing wall ties.19c. Removal of wall panels.19d. Removal of deck panels.

20. Cleaning of panels.

21. Fixing of working platforms with brackets.22. Erection of Safety posts / rails.

23. Applying Form release agent.


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Introduction

Slipform has been accepted as a precise construction technique within acomparatively short period of time an indication of its considerable popularity.

This popularity has in turn encouraged further research ensuring the adoption

of new methods and modern materials, which have firmly established

slipforming as an economical, rapid and accurate form of construction.

Now that it is properly developed, the technique can be applied to many

different forms of structure, including tapering formations with straight

or parabolic profiles incorporating constant reductions in wall thickness.

Traditional applications for slipforming are silos, chimneys, bridge piers,

water towers, special application like construction of pylons, lift core wall of

building, lining for tunnel shaft, framed structures etc.,

Principles of Slipform

Slipform construction, also referred to as sliding form construction, is similar

to an extrusion process. Plastic concrete is placed in the forms, and the forms

act as moving die to shape the concrete. Once the form has been filled with

fresh concrete and hardening has started the form is gradually raised by the

lifting devices on which it is suspended. The rate of movement of the form

is regulated, so that the forms leave the concrete after it is strong enough to

retain its shape while supporting its own weight. Pouring of concrete, tying of

reinforcement, fixing of openings/inserts etc are performed gradually from a

working platform.

An average sliding speed of 200mm an hour is common, rising to 300mm

an hour under the best conditions and 100 to 150mm an hour when large orcomplicated structures are being slipformed.

Design Considerations:

The slipform should be designed so that the loads to which its various

component parts are subjected are uniformly distributed, and the yokes are

loaded as uniformly and axially as possible to avoid their overturning. The

jacks should not be located in wall openings as for as possible. The loading

should not exceed the lifting capacity of the jacks. The loads acting on slipform

can be classified as follows,

Slipform


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BASIC LOADS

Dead load due to the components

Live loads due to Concrete

Friction between form and concrete

Workmen

Materials

Machinery

Other installations

Auxiliary load due to the way of application of live loads,

Crowds of workmen

Piles of materials

Shocks produced by material unloading

Accidental Loads

Wind pressure

Adhesion between concrete and form due to long interruption.

Friction due to incorrect position of form

Failure of one jack

Extraordinary Loads

Breaking of certain members of the slipform

Failure of two adjacent jacks

Minimum concrete strength required for slipform application,

2 Kgf / cm 2 - when releasing the form.

4 Kgf / cm 2 - when coming out from the form.

20 Kg / cm 2 - after 24 hours since pouring.

200 Kg / cm2 - after 28 days.


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Type of Slipform

The slipform can be broadly classified into,

Straight slipform.

Tapering slipform.

Slipform for special applications

Typical structures that are constructed using straight slipform technique are,

Silos

Cylindrical chimneys

Water tank shafts

Columns

Typical structures that are constructed using Tapering slipform are,

Conical chimneys

Ventilation stack

Tapered bridge piers

Typical structures that are constructed using Special slipform are,

Lift cores

Framed structures

Preheater building

RCC Pylons

Construction of block of flats, lifts and stair- well, bridge piers, preheater andRCC pylons for boiler supporting structure using slipform techniques comes

under special applications because of their complex sizes, shapes and loads

to be lifted along with slipform, like walkway trusses, etc. which is essential

for construction.

Assembly Procedures

Stright SlipformPosition the vertical and horizontal reinforcement with correct cover.

Casting of the starter. (min: 150 - 200mm)


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Check starter for the correctness in level and diameter.

Fix the inside and outside staging brackets/erect scaffold pipes, if

required.

Fix timber runners connecting the walkway brackets. / Level the surface

using cement mortar.

Check the level.

Tie the vertical and horizontal reinforcement upto shutter top height.

Mark the position of inside and outside yokes in the starter, starting from

the tower location.

Ensure that three sets of yokes are located in between two tower

verticals.

Align the panels and introduce steel washers at regular intervals to

maintain

4mm slope both inner & outer faces.

Fix top and bottom waler pipe. Fix external supports, both horizontal and

inclined to align the shutter.

Fix filler panels.

Repeat the operation 10 to 12 for outside and make sure that washers are

introduced at the bottom of shutters to achieve 4mm slope towards inside.

Fix the waler shoes, inside and outside yoke legs. Adjust waler shoe and

check the verticality on both faces

Keep timber supports between top & bottom walers at yoke location.

Align the form panel by external supports.

Fix the yoke beam generally two numbers at the bottom and one number

at top.

Check the level of yoke beams with spirit levels.

Fix the inside and outside walkway brackets.

Finish the final alignment by suitably adjusting the waler shoe bolts. Ensure

that all walers are touching the form panels. Provide packing wherever

required.Fix the flying tie rod assembly and support the center rings. Ensure uniform

tightness is maintained in all the spokes.


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Tapering SlipformPosition the vertical and horizontal reinforcement with correct cover.

Casting the starter. (Provide pocket or pipe sleeve in yoke locations to

accommodate tapered sleeves )

Check starter for the correctness in inclination level and diameter. Chip

and finish the same, if required.

Erect central tower using L&T HDT system and fix planks on the top after

aligning the top construction accurately.

Fix the centre frames with the help of scaffold pipes, if required.

Pre assemble the trusses and spiders after marking the location of inside

yoke leg, assemble with yoke legs, yoke beams, adjusting screws as per

initial setting diagram , erect them and provide support.

Check the level of truss.

Mark the position of inside and outside yokes in the starter starting from

the tower location.

Assemble the panels along with form supports with pre assembled

condition.

Fix top and bottom waler. Fix external supports both horizontal and inclined

to align the shutter.

Fix inside and outside consoles and upper outside console and fix

planks.

Fix the yoke beams at top & bottom.

Check the level of yoke beams with spirit levels.

Fix the top platform pipes with guard railings.Fix the jacks & turnbuckle jacks and finish the hydraulic connections.

Test for leakage in the line and jacks and replace, if required.

Fix water level tubes & check the platform level. Adjust if required.

Check the the final adjustment as per the initial setting diagram.

Fix the handrails.

Fix the tapered sleeves & jack rods.

Energise the slipform before filling the form and removing temporary

supports.


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Start the concreting after completion of all activities and checking the

availability of all materials as given in the planning for slipform.

Fix the inside and outside hanging scaffold and do the decking.

Tie the safety net.

Assembly of Stair Tower:

The verticality of the stair tower shall be checked only with plumb bob.

Stair tower shall be checked for verticality at every support location. If any

deviation is found it shall be corrected then and there, by adjusting support

length. The deviation in verticality shall not be more than 10mm for every

10M of height and maximum 50mm for the overall height.

CARE DURING SLIPFORM OPERATIONS:

1. Uniform layer of concreting.

2. Regular cleaning of shutters.

3. Penetration testing of concrete, for setting time.

4. Freeness of tapered sleeves.5. Periodical plumb readings.

6. Adjustment for tilt & twists.

7. Prevent overflowing of concrete.

8. Maintain a free board of 100 mm.

9. Uniform distribution of load on the platform.

10. Lowering of unwanted materials periodically.

11. Proper handling of lasers.

12. Cooling of jacks where the temperature is very high.

13. Protection of high pressure hose.

14. Protection of turnbuckle spindles.

15. Greasing of all moving parts / outside the shutters.

16. Ensure free movement of shutters, walers, intermediate form supports,

planks and handrails.


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17. Consistent quality of concrete.

18. Periodical checking of concrete slump.

19. Fixing of required setting time for concrete based on slipping speed.

Dismantling Procedure

Stright Slipform:

1. Provide coil nuts in the final layer of concrete approximately 300 mm

from top of concrete.

2. Fix dismantling brackets, handrails, finish planking and transfer the load

of slipform assembly to the brackets.

3. Remove the flying tie rod assembly and lower the same.

4. Remove the inside and outside hanging scaffold and shift the planks to

the staging brackets.

5. Remove the jacks and sleeves.

6. Remove the yoke assembly, which consists of yoke legs, yoke beams

and waler shoes.

7. Remove inside & outside walers.

8. Remove the wall forms, while removing the waler.

9. Extract the jack rods and grout the holes.

10. Remove dismantling brackets after completing other works.

Tapering Slipform:

1. Provide coil nuts in the final layer of concrete.

2. Fix dismantling brackets, handrails, and fix the planks.

3. Remove and re-locate the R.G.Hoist to the required location(if it is

there).

4. Transfer the load of slipform assembly and main truss to the wall.

5. Remove & re-fix the safety net with the temporary platform.

6. Remove the inside & outside hanging scaffolding.


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7. Remove all the hydraulic hoses, manifolds and the jacks.

8. Remove the intermediate form supports, spindles, turnbuckle, shutters,

form supports, wall thickness screws, radius screws and yoke beams.

9. Remove inside & outside yoke legs.

10. Dismantle the truss assembly.

11. Extract the jack rods and grout the hole

12. Lower the materials then and there.

13. Remove the dismantling platform.

Slipform Reinforcement:

The progress of slipform is mainly determined based on the time consuming

for concrete pouring speed and reinforcement tying. if any delay in these

two the progress will affect drastically. As the space available for tying the

horizontal is restricted in slipform, it is very essential to plan all the activities

well in advance and to be prepared before starting of slipform.

The following points have to be considered while making the schedule.

The length of vertical/horizontal bars should be restricted to 5 mtr. due to

the constraints in lifting and handing at heights.

The diagonal bars around openings should be avoided.

Wherever stirrups are used it should be in 2 pieces only.

It is not possible to have verticals in yoke locations and hence alternate

bars should be placed nearby.

Wherever concrete is taken through a chute the verticals below the chuteshave to be lapped with smaller lengths by means of welding.

The total requirement of reinforcement should be cut / bent and kept near

the slipform structure before starting slipform. The stocks should be kept with

proper tag for easy identification.

Refernce Standards And Codes

1. ACI 318- Building code requirements for reinforcement concrete.

2. ACI 304- Recommended practice for measuring, mixing, transporting

and placing concrete.


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3. ACI 313-77 R83 - Recommended practice for design and construction

of concrete bins, silos and bunkers for storage of granular materials.

4. ACI 347-78 - Recommended practice for concrete formwork.

5. ACI 313-77 - Allowable tolerance.

6. ASTM C 403-70 - Penetration resistance method of concrete setting.


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Summary of LabourProductivity Norms

Sl.

No.

Type of Work UnitNorms

In M.Hrs1 Erection of Access Tower (2.5 X 2.5 M) RM 32

2 Dismantling of Access Tower (2.5 X 2.5 M) RM 15

3 Erection of Stair Tower (2.5 X 2.5 M) RM 16

4 Dismantling of Stair Tower (2.5 X 2.5 M) RM 8

5 Straight Slipform Assembly YOKE SET 75

6 Straight Slipform Dismantling YOKE SET 55

7 Slipform Operation - Straight Slipform M2 1.22

8 Assembly of Pre-Stressed Silo YOKE SET 92

9 Slipform Concrete - Manual M3 22

10 Slipform Concrete - Rmc With Pump M3 15

11 Slipform Concrete - Rmc With Hoist M3 25

12 Slipform Reinforcement - Straight Slipform MT 65

13 Extraction of Climbing Rod RM 0.34

14 Taper Slipform Assembly - Upto 24 Yoke Set MT 56

15 Taper Slipform Assembly - 16 To 48 Yoke Set MT 49

16 Taper Slipform Dismantling - Upto 24 Yoke Set MT 49

17 Taper Slipform Dismantling - 16 to 48 Yoke Set MT 46

18 Re-Assembly of Slipform - Taper Slipform MT 78

19 Re-Assembly of Slipform - Straight Slipform YOKE SET 90

20 Slipform Operation - Taper Slipform M2 2.45

21 Slipform Reinforcement - Taper Slipform MT 90

22 Erection of R.G.Hoist NOS. 827

23 Re-Location of R.G.Hoist NOS. 1365

24 Dismantling of R.G.Hoist NOS. 675

25 Pre-Stressing Works in Silos MT 170

Note: The productivity norms will vary based on volume of work involved and numberof structures to be constructed in the project.


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The execution of slipform job requires a complete and detailed preparation

as many simultaneous and successive operations are involved. The method

of construction, preparation of scheme drgs., calculating the requirement ofslipform materials, equipment, tools & tackles, consumable, manpower etc

needs thorough planning.

It also involve mix design, admixtures to be added for the concrete,

reinforcement around openings and planning for other related works on the

slipformed structure.

Straight SlipformOn large site with several structures built with the same slipform, planning

includes

Work below slip form level

Detailed programme for the wall

Work involved in intermediate floors, if any.

Embedment/ pockets and other installations during slipform

Slipform Materials

The number of yokes for each silo is calculated based on the diameter of the

silo. The yoke to yoke distance is normally kept between 1.25 and 1.35 m.

Once the number of yokes required is calculated the list of materials can be

prepared from the master list. The requirement of jack rods depends on the

height of structure. Always keep 5% extra material as spare.

The length of yoke beams = Wall thickness + 1000 mm.

Normally 2Nos. Yoke beams at the bottom and 1 at the top are fixed.

Wherever yokes are used for supporting some lifting arrangements, there the

top yoke beams also shall be 2 no back to back.

Slipform Equipment:

The capacity of Jacks to be deployed is depends on the following loads:

Basic Loads:

Dead weight of yokes,

Slipform Planning


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Dead weight of Concrete lifting arrangements

Weight of Platform with 40thk plank

Weight of wooden Runners 125*75mm

Total Dead Load = X

Live Loads

Live load over platform @ 200kg/sqm

Weight of Concrete 0.5 cum

Weight of Steel (reinforcement, jack rod stacked on platform)

Weight of Equipment

Total Live load Y

Frictional forces @0.173kg/m (length along the wall sides) Z

Total Load on Slipform L = (X+Y+Z) * t

Required Jacking Capacity (W) should be with 1.4 factor

Note:- Jack shall not be loaded more than 80% of its capacity.

Concrete Equipment

The quantity of concrete required per meter height should be calculated

first. The slipping speed can be assumed based on the quantity of concrete ,reinforcement, pre-stressing and other related items. Rate of rise depends on

the above and setting time of concrete. Once the slipping speed is assumed

the concrete requirement per shift can be calculated.

Once the quantity per shift is known, with 25% spare capacity, the size and

number of mixing and lifting equipment shall be decided.

Consumable:The standard list of consumable is given along with master material list. The

quantity of electrodes, gas, grease, oil etc. can be given approximately. The


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wire rope required for hoisting to be calculated separately based on height of

the structure.

Timber Requirement

The requirement of timber is for the following areas.

1) Working platform 2) Masons platform 3) Runners for supports

4) Planks for the bracket platform if assembly is taken up from higher

elevation.

Working Platforms

Timber platform consisting of four parts

a) Supporting runners 5x 3x7 long & 6 long

b) Wooden planks 6 x 1 x 6 long.

c) Toe board size: 4 x 1 x 6 long

Manpower Requirement:

The requirement of labour for various activities can be calculated based on theproductivity norms, site conditions and type of structure.It is preferable to engage

one single agency for the entire slipform works in a project to have better control

over productivity and also optimum use of workmen with multi skill.


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Tunnel Form

Description of Half Tunnel Form


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Movement of Formwork


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Kickers


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Ties


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Protection Platforms


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Aluminium formworkRefurbishment

A) Process involved

a) Manual cleaning

A working table to be made and the Concrete lumps, dirt shall be cleaned by

the scrapper and wire brush.


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a.1) Tools Required

Ball Pein Hammer

Chisel

Scrapper

b) Machine Cleaning

b.1) Tools Required

GQ 4 Grinding Machine

4 circular buffing wheel

6 RUBBER BACK UP PAD

c) Dent Removal

Side rails are cleaned with GQ4

Grinding Machine, 4 circular

buffing wheel.

Remove the Dents if any in the

panel using a hammer and a

flat base plate. Make sure that

no point contact is there during

this process.


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d) Welding

After removing the dents,

inspect the panel for any

cracks in the welding joints.

If found it shall be welded.

Surface cleaning shall be

done with the sander disc,

ensure that smooth rendering

only is done.

d.1) Tools Required

TIG Welding machine

Welding coil spec :Aluminium filler wire 1.2 mm. Er 5356. Make: Indaco

e) Surface cleaning


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e.1) Tools Required

AG7 & AG4 GrindingMachine ( RPM 5000)

Sander Disc (80/120 Grade)

f) Lacquering and Stenciling

Safety items

Hand gloves

Nose mask

Ear plug / ear muff

Apron

Goggles white

Brushing viscosity of lacquer can be 30 sec. Surface to be touch dry with in 10min of application. Allow over night and use. Thinner- MCC 2507.


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Plywood

Plywood is an important commodity which plays a key role in the formwork

both in terms of quality and cost (10-13% of formwork cost). The finish of

the concrete surface where plywood is used as sheathing members is purelydependent on the quality of the plywood. Plywood is a manufactured wood

made up of thin sheets of woods and compressed together with a glue which

gives higher strength when compared to a normal wood.

Indian government has put stringent rules for cutting of wood which has

initiated the local ply manufactures to import the logs (poplar and birch wood)

from various foreign countries for the production of plywood. The performance

of the plywood (for formwork application) is mainly based on the glue whichthey use for binding (mostly wood species used by all the manufactures are

common).

Plywood shall be tested at site premises before accepting. The testing facilities

are established in all major projects. Incase if the same is not available

respective site representative can contact the Cluster BSCC in charge for

extending the support.

Plywood procurement is centralized in order to deliver a quality product to the

projects at a competitive rate.

Plywood request format shall be filled and sent to the respective cluster BSCC

in-charge for clearing the procurement. Cluster BSCC in-charge will in turn

take concurrence from Head BSCC.

Now about 60 to 70% of the plywood requirements for the projects are serviced

from china and the followingare the details pertaining to the

same

Item Code 765610020

Repetitions 8 to 10

Price approx 20% cheaper

than domestic ply

Delivery period 60 to 65 days


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Form Release Agent

Approved Form Release Agents

Its a management decision that apart from these solvet based form release

agent other products cannot be used until unless it is approved by Cluster /

HQ BSCC.


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Formwork Lift

A system which complements the ability of Table form to do faster construction.

It is turning out to be one of the most important equipments which will be

extremely useful in improving the functional aspect of L&Ts trademark Table

form System. Till now, our Table form System was totally dependent on Crane,

especially while shifting the Table vertically from one Floor to the next. RCS

would not only help in drastically reducing this dependability on Crane but

also have a positive impact on the Labour Productivity subsequently helping in

reduction of Cycle time. Though the system was procured from the formwork

supplier the self climbing equipment was indigenously developed by BSCC-

HQ which further eliminated the crane requirement for floor to floor shiftingof RCS.

A project site will be debited with a internal hire charges of ` / Month

Cycle time

Labour Productivity -


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ACS - Automatic Climbing System

Self Climbing System ACS - Fields of Application

Self Climbing System ACS - Hydraulic System

Self Climbing System ACS


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Hand tools required (work place)


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ROLES & RESPONSIBILITIESOF FORMWORKENGINEER AT SITE

1. Preparation of Formwork programme based on the overall construction

programme

2. Finalization and coordination of Shuttering Scheme

3. Ensuring effective and proper utilization of shuttering and staging

materials

4. Planning and allocation of materials / labour / Plant & machinery for

formwork activities in coordination with concerned persons at site

5. Educating sub-contractors on System formwork

6. Making mock-up of various System formwork

7. Periodical reconciliation of formwork materials

8. Preparing S-6 A schedule (requirement / release) and sending the same

to Cluster Office

9. Preparing stock statement of formwork materials both in Units and in

Nos., with area of shuttering done category-wise, Plywood / Timber

procured during the quarter / till date and Productivity report.

10. Maintain close interaction with stores and site people for proper

accounting of materials

11. Despatch and receipt notes to be sent to Cluster Office

12. Making of purchase requisition for Plywood and Timber after thoroughly

analyzing the number of repetitions

13. Receipts of plywood / formwork materials to be acknowledged after

quality checks to Cluster Office on monthly basis

14. 100% materials reconciliation at the end of the job

15. Looking after pre-despatch maintenance


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16. Ensuring that despatched materials are in usable condition.

17. Sending monthly reports to Cluster office.

ROLES & RESPONSIBILITIESOF SITE FOREMAN / CHARGEHANDS

1. Material Accountability right from the materials receipts at site to despatch

to other site after the completion of the job.

2. Small items have to be issued to the sub contractors from stores and

make them responsible for those items. For their sake, tool box can be

issued. These items have to reconcile after the completion of the job.

3. Proper usage of the formwork materials and avoid the misuse (usingbracing as leverage) of the same.

4. Ensure proper house keeping at site as well as the maintenance

(greasing / oiling after deshuttering etc.) of the formwork materials

5. Deshuttering right on time to achieve maximum number of repetitions of

formwork materials.

6. Optimum use of nails in H beam.

7. Quality in works carried out at site so that tolerance should within

tolerance limit.

8. Formwork labour productivity should be monitored closely to achieve the

management goal.

9. Training of Labour and Sub contractor workmen at site either by mock

up or classroom programme by drawing sketches.

10. Adoption of safety standards while working by fully equipped with

PPE and using the complete system at site (do not miss any bracing /

connecting pin / locking pin etc.).

11. Use of stocking pallets.

System formwork functions, applications& Safety


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1.Foundation formwork(All steel)

Functions/Salient features

1. All the components are made out of steel

2. No timber is used

3. Easy to assemble

4. Higher labour productivity

5. High quality concrete surface finish

6. Suitable for side formwork of sub structures .

7. Capable of withstanding the concrete pressure of 10KN/sq.m

Sequences of assembly

1. Materials stocking near to layout

2. Cleaning and oiling

3. Layout marking

4. Floor forms positioning

5. Accessories fixing

6. Line and verticality checking

7. Concreting

8. Deshuttering

Safety appliances required

1. Safety helmet

2. Manila rope 20 mm or 25 mm

Safety precautions

1. During transporting and stocking the materials proper care has to betaken


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2. While lowering the materials from ground level to down level additional

care has to be taken

2.Wall/Column formwork


1. System can be done by Crane and Manual

2. Using standard component wide range of plan configurations are

possible

3. High strength tie system bear large concrete pressure and avoid load

bearing struts

4. Provisions for fixing scaffolding platform and alignment units built-in

5. Offsetseliminated producing good concrete finish




3. Layout marking/starter casting and layout checking

4. Panel positioning

5. Accessories fixing and alignment

6. Line, level and verticality checking

7. Concreting

8. Deshuttering


1. Safety helmet

2. Safety belt

3. Safetynet for taller structures


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4. Manila rope 20 mm or 25 mm

Safety precautions

Crane operation

1. Sling capacity and quality of sling has to be checked

2. D Shackle capacity has to be checked

3. Experienced signal man has to be engaged for propersignaling to the

crane operator

4. Ensure that there is no loose material on the panels or platforms

5. Before lifting the panel, necessary pre checking has to be done on the

panels.

Manual operation

1. Use the necessary personal protection appliances such as helmet and

belt.

2. Use the proper tool for adjusting the panel height and line

3. Flex system


1. System can be used up to floor height of 4.40 mtr.

2. Removable folding tripods make selected individual props self

-standing

3. Flexibility in adjusting the individual prop height and spacing between

props

4. Components are easy to handle manually

5. Steel members can also be used for decking

7. Eliminating the skilled labour at site


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2. Prop layout marking

3. Main Prop positioning with tripod

4. Intermediate props positioning with supporting head

5. Placing of fourway head, primary layer beam and secondary layer

beam

6. Levelingof beams with the help of props

7. Placing of plywood.

8. Levelling of seathing and checking


10. Concreting

11. Dismantling

12. Cleaning

13. Transporting and stocking


1. Safety helmet

2. Safety belt

3. Safety net for taller structures whereever it is necessary

4. Manila rope 20 mm or 25 mm wherever it is necessary

Safety precautions

1. All the main props shall be fitted with folding tripod

2. All the indermediate shall be fitted with supporting head


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3. Do not use tor steel in place of locking pin

4. In ground level work , proper earth compaction and necessary bearing

below the prop shall be given

4.Heavy duty tower system -HDT


1. Higher loading capacity of 250 KN and needs bracing at every 6 m in

height both horizontal directions with permanent other towers

2. Can be assembled in plan dimensions of 1524x1524 mm and

2250x1524 mm, by choosing the type of bracing both configurationswith four legs of 62.5 KN capacity each.

3. Height adjustments up to a minimum of 800 mm is possible by utilising

both top and bottom tower spindles

4. Easy to obtain plumb using tower spindles

5. Tower as a whole can be shifted(rolled) manually by attaching transport

devices to the legs



2. Tower layout marking

3. Frame fixing with necessary accessories at bottom and fixing of bracings

between the frames

4. Placing of necessary accessories at top with U head and steel waler

5. Placing of beam span and H-Beams

6. Levelling of beams

7. Placing of bottom/sheathing

8. Leveling of bottm/sheathing

9. Checking of levels and verticality


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11. Concreting

12. Dismantling

13. Cleaning



1. Safety helmet

2. Safety belt



Safety precautions

1. Every 6 mtr interval bracing has to be fixed with permanent structure or

tower to tower

2. Ground level earth has to be compacted well for better loading

3. Materials conditions has to be checked and badly damaged frames and

bracings to be avoided

4. Do not use tor steel in place of locking pin

5. Stair towerFunctions/Salient features

1. Safe and convenient access up to 100 mtr height in the form of stair with

suitablebracing with bracing with permanent structures every 6 mtr

2. Structural skeleton of HDT with a few additional accessories.

3. Can be handled as a single unit with a crane


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3. Frame fixing with necessary accessories at bottom with foot plate , spring

locking pin and tower spindle

4. Placing of 1.20 m frame with necessary bracing for one level

5. Checking of level and verticality for one level

6. Fixing of stair brackets ,grid iron ,connection angle , idermediate railing

and inner hand railing7. Every 6 mtr height necessary bracing with permanent structure

8. Dismantling

9. Cleaning



1. Safety helmet

2. Safety belt



Safety precautions

1. Every 6 mtr interval bracing has to be fixed with permanent structure

2. Ground level earth has to be compacted well for safe loading

3. Materials conditions has to be checked and badly damaged frames and

bracings to be avoided

4. Do not use coir string or binding wire in place of M 10 bolt and nut with

grid iron

5. Do not omit any bracing


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6. Access scaffolding


1. Exclusively used for scaffolding purpose up to 40 mtr height braced atevery 6 mtr with structure

2. Frames are lighter in weight and 1.0 mtr in width

3. This provides free movement for workmen without any obstuction at all

levels

4. Bracing 2H-225 serves as an essential bracing for stability as well as

hand rail on the face away from the strutures




3. Frame fixing with necessary accessories at bottom with LD foot plate ,

spring locking pin and LD tower spindle

4. Placing of frame with necessary bracing for one level

5. Checking of level and verticality for one level

6. Fixing of platform hanger and walk way 225

7. Every 6 mtr height necessary bracing with permanent structure

8. Dismantling

9. Cleaning



1. Safety helmet

2. Safety belt


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Safety precautions

1. Every 6 mtr interval bracing has to be fixed with permanent structure

2. Ground level earth has to be compacted well for safe loading

3. Materials conditions has to be checked and badly damaged

frames,walkway 225 and bracings to be avoided

4. Do not use coir string or binding wire in place of Platform hanger

5. Do not omit any bracing

7. Lift shaft formwork


1. Provides a platform for shutter and workmen inside the closed area of

liftwell and a deshuttering mechanism for stripping of formwork without

dismantling the panels and seathing

2. Panels can be lifted integrally in deshuttered position along with platform

and erected for next pour

3. A few components are required in addition to all components of wall//

column formwork



2. Erect the platform in the pocket loations in the inside wall face with

climbing pawl arrangements

3. Level the platform with the help of bolt given in the climbing pawl

4. Erection of inner wall panels with the necessary accessories including tie

arrangements


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5. Erection of outer panels with necessary accessories

6. Checking of dimensions,levels and verticality

7. Concreting

8. Releasing of inner panels for minimum of 20 mm on all the four sides

9. Lifting of inner panels with platform for next level

10. Lifting of outer panels



1. Safety helmet

2. Safety belt

3. Safety net for taller structures where ever it is necessary

4. Manila rope 20 mm or 25 mm where ever it is necessary

Safety precautions

1. Sling capacity and quality of sling has to be checked

2. D Shackle capacity has to be checked

3. Experienced signal man has to be engaged for Proper signaling to the

crane operator

4. Ensure that there is no loose materials on the panels or platforms

5. Before lifting the panel , necessary pre checking has to be done on the

panels.

6. Ensure the gap before lifting the inner panel platform

8.Framed formwork Frami


1. Sturdy and torsion proof hollow sectioned steel frame


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2. Hot-dip galvanished for high Durabilty

3. High grade 15 mm thick film coated sheathing for high wear resistance

4. Easy to fasten accessories

5. Integrated handles for easier handling

6. Permissible concrete pressure on formwork 40 KN/sqm

7. Can be used for foundation , column and wall



2. Place the panels with all the necessary accessories as required

3. Check the dimension,level,line and verticality

4. Concreting

5. Releasing of inner panels for minimum of 20 mm on all the four sides

6. Lifting of inner panels with platform for next level

7. Lifting of outer panels



1. Safety helmet

2. Safety belt


Safety precautions

1. Provide the tierod only where the given the provision is given

2. Do not omit any components

3. Framiadj strut 260 is to be anchored properly


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9.Climbing formwork


1. Large area form work can be taken up

2. Any height is possible

3. High degree of safety as on the ground

4. Faster and economical

5. Can be used for inclined structures also

6. Formwork is safely anchored to concrete at all times

7. Simple system of working platforms


1. Safety helmet

2. Safety belt


Safety precautions

1. Platform timbers should be free from cracks ,fungus attack and dead

knots

2. Hand rails pipes are to be fixed properly

3. Stop anchor threaded length shall be 55 mm inside the anchor cone

4. Climbing cone threaded bore length shall be ------

5. Plat form shall be free from gap between timber joints


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REINFORCEMENT WORKS

Category of Reinforcements

Carbon steel bars (plain and deformed).Cold reduced plain and deformed steel wire fabric.

Stainless steel bars and fabric.

Galvanized carbon steel bars and fabric.

Epoxy coated carbon steel bars.

Fiber Reinforced Polymer (FRP) rebar- [Non steel reinforcement]

Reference Indian Standards:

IS 1786 - 2008 - Specification for High Strength Deformed bar and Wires

for Concrete Reinforcement.

IS 432 PART 1- 1982 - Specification for Mild steel and Medium tensile

steel bars and hard drawn steel wire for concrete reinforcement

IS 432 PART 2 -1982-Specification for Mild steel and Medium tensile steel

bars and hard drawn steel wire for concrete reinforcement.

IS 2502 -1963 - Code of practice for Bending and Fixing Bars for Concrete

Reinforcement.

SP 34 -1987 Hand book on Concrete Reinforcement and Detailing

Reference International Standards.

BS 4449 Carbon steel bars for concrete.

BS 7295 Fusion bonded epoxy coated steel

BS6744 Stainless steel

BS 4483 Steel fabric

BS 4482 Hard drawn wire

BS 8666 Scheduling dimensioning, bending and cutting of steel

reinforcement for concrete - Specification

ASTM A 615 for carbon steel rebar.

ASTM A 706 for seismic rebar.

ASTM A 955 for stainless steel rebar.ACI 440 for FRP bars

DIN 488 Reinforcing steels


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How to Calculate Hook & Bend Allowance

REBAR TYPE

Bar Diameter,

d 25mm

Bar Diameter,

d > 25mm

k

ValueHook Bend

k

ValueHook Bend

Mild Steel 2 9d 5d 3 11d 5.5d

Medium Tensile Steel 3 11d 5.5d 4 13d 6d

Cold Worked Steel 4 13d 6d 6 17d 7d

Note:

All the Value is to be rounded off to nearest 5mm.

If the calculated result is


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Calculated Hook & Bend Allowance:

Nom

inalSize

of

Bar

(D)

Hook Allowance (H) Bend Allowance (B)

Mild Steel

Medium

Tensile

Steel

Cold

Worked

Steel

Mild Steel

Medium

Tensile

Steel

Cold

Worked

Steel

Min

Rec

om

md.

Min

Rec

om

md.

Min

Rec

om

md.

Min

Rec

om

md.

Min

Rec

om

md.

Min

Rec

om

md.

5 75 - 75 - 75 - 75 - 75 - 75 -

6 75 - 75 - 75 - 75 - 75 - 75 -

8 75 - 90 - 105 - 75 - 75 - 75 -

10 90 - 110 - 130 - 75 - 75 - 75 -

12 110 - 130 - 155 - 75 - 75 - 75 -

16 145 - 175 - 210 - 80 - 90 - 95 -

20 180 - 220 - 260 - 100 - 110 - 120 -

22 200 - 240 - 285 - 110 - 120 - 130 -

25 225 - 275 - 325 - 125 - 140 - 150 -

28 250 310 310 365 365 475 146 155 155 170 170 195

32 290 350 350 415 415 545 160 175 175 190 190 225

36 325 395 395 470 470 610 180 200 200 215 215 250

40 360 440 440 520 520 680 200 220 220 240 240 280

45 405 495 495 585 585 765 225 250 250 270 270 315

50 450 550 550 650 650 850 250 275 275 300 300 350


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LARSEN & TOUBRO LIMITED -ECC DIVISION

QUALITY FORMAT

BAR BENDING SCHEDULE

PROJECT : DATE :

AREA/BUILDING :

DESCRIPTION OF WORK :

TIME

:

DRG.REF . :

MEMBER

BAR

NO.

DIA. OF

BAR

NO.PER

MEMBER

NO.OF

MEMBER

TOTAL

Handbook Foundation Form Work Rebar Concrete

Documents

Transcript of Handbook Foundation Form Work Rebar Concrete