CONSTRUCTION AND DESIGN OF MULTISTOREY BUILDING

ATUNITECH LTD

SUBMITTED BY: UNDER THE GUINDANCE OF

ABHIMANYU PARIDA RAJIV GUPTA

1040241 FACULTY COORDINATOR

Projects Undertaken

1. Construction of residential building (escape)1.1 Excavation, Layout and Foundation

1.2 Column layout, shuttering and casting

1.3 Slab, Beam shuttering and casting

1.4 Important Components

2. Introduction to bonded slab post tensioning2.1 Post tensioning

2.2 benefits

2.3 Tendons and stressing

Projects Undertaken

3. Design of building component

3.1 Formwork design

3.2 Staircase design

3.3 Deep Beams

3.4 Slabs

Excavation, Layout and Foundation

Excavation is a process of making trenches by digging up of earth for the construction of foundations and basements.

Excavation level at escape site is 219.825 mm Excavation is done by the JCB on the hourly basis After the excavation the surface is leveled called surface

dressing Layout is done on the PCC poured over leveled surface. Column and foundation (raft ) steel is then laid as per

drawings.

Points to take care:-

layout should be checked properly. Check any difference between architectural and structural

drawings regarding location of column. After excavation check the stability of temporary structures built

near the excavated ground. Before laying raft reinforcement, shuttering wall which is mainly

brick wall should be built and should be filled with soil on other side.

Check the direction of chair bars in the raft

EXCAVATION

LAYOUT

RAFT FOUNDATION

COULMN CASTING

On the raft the column layout is done. Layout for starter. The column ties and link bars are provided as per column

reinforcement drawings and general specifications. Displacement of main bars should be provided with L bar The plumb of formwork should be checked. Height of cast should be calculated accurately. Avoid caps as far as possible.

LAYOUT , PEDESTAL & STARTER

LINKS & TIES

PLUMB & FORMWORK, CASTING,CURING

SLAB, BEAM SHUTTERING & CASTING

beam bottom is first laid on the column and then slab formwork is laid

After the reinforcement, the slab is checked for steel as per drawings and level required.

A camber of 5 mm in provided in the center of slab.

Casting of slab should be discontinue at l/3 from the support.

SLAB STAGES

IMPORTANT COMPONENTS

Key in column

Water bar

Binding materials

Expansion joint

KEY IN COLUMN

since the height of column is very large, hence it is not possible to cast the column at one time, to cast the column later the key is made at the junction so that the proper bond between the old concrete and new concrete is formed.

KEY IN COLUMN

EXPANSION JOINT

Since concrete is subjected to volume change. Provision must be made to cater for the volume change by way of joint to relieve the stresses produced.

Expansion joint is function of length Buildings longer than 45 m are generally provided with one or

more expansion joints. Material used as expansion joint material is armour board

whose thickness is 25 mm.

EXPANSION JOINT

Expansion joint material, size is 25 mm

Expansion joint in building

WATER BAR

Water bar is provided in the retaining wall o that the moisture can’t move from the soil to the joint. Water bar is basically provided at the constructions joints of retaining wall of two different towers

WATER BAR

BINDING MATERIALS

Since the thermal expansion of concrete is different from that of masonry. The interface between the concrete and the masonry is liable to crack. To avoid this crack the chicken wire mesh is used to avoid the crack and also provides the better grip for Masonry with concrete.

Similarly when the drainage pipes are laid along with the outer wall then again the connection between the pipe and the wall has different coefficient of temperature change hence they are joint to the concrete by lead keys.

In the toilets and kitchen sunken portion the joints in any case are packed by water proof and non shrinkable material.

BINDING MATERIALS

Chicken wire mesh between brick masonry and concrete

Connection of pipes with concrete

Chicken wire mesh in conduits through concrete

WATER PROOFING

Water proofing has remained as an unsolved complex problem

Use of plasticizers, super plasticizers, air-entraining agents helps in reducing the permeability of concrete by reducing the requirement of mixing water, hence can be also be regarded as waterproof material.

Some of approved water-proofing compound by the company

are:- pidilite, cico, fosroe, baushimine, unitile.

Water-proofing cement paint:- super snoweem

WATER PROOFING

Water proofing in sunken portion of kitchen and bathroom

WP in sunken portion at ground level

WP in retaining wall

WATER PROOFING IN GARDEN AREA

For water proofing in garden area the soil is first leveled and then rammed to achieve the maximum density

The PCC is then laid down mixed with tape Crete (a water proofing compound)

After PCC the plaster of fibrous material is done. the bituminous sheets are laid by heating it with the welder. On

those sheets the drainage pipes are laid down with suitable slope and these pipes are covered with geo-fabric sheets.

Again the plaster is done. On the plaster the 40 mm aggregates are laid.

On the aggregate the geo-fabric sheets are laid down on which the sand is placed & on the sand the soil ,along with fertilizers, is placed on which the gardening is done for the non tower area.

WATER PROOFING IN GARDEN AREA

Sandy soil PCC mixed with tape

Crete (water proof compound)

Texas (bitumen) sheet Drainage pipe 40 mm aggregate Geo-fabric sheet Sand

INTRODUCTION/BENEFITS

Post-tensioning is a method of reinforcing (strengthening) concrete or other materials with high-strength steel strands or bars, typically referred to as tendons

allows longer clear spans, thinner slabs

lower overall building height for the same floor-to-floor height.

allows a high degree of flexibility in the column layout, span lengths and ramp configurations

POST TENSIONING

PLACEMENT OF TENDONS Positioning and fixing of casting and block-outs to the edge formwork

or construction joint formwork The support bars shall be prepared in advance. Lay tendons according to tendon layout in accordance with the

drawings. Fix tendons to correct profiles with support bars and chairs and the

tendons are made with provisions for grouting using grout using grout vents and grout hoses

Prepare installation report for every installation as per the enclosed format.

tolerance of tendon profiles is recommended as follows: **vertical: + 5 mm (at lowest and highest points) Horizontal: + 100 mm

LOADS ON FALSEWORK

Loads on Falsework are any combinations of the following:

Dead loads, Imposed loads, Environmental loads, Incidental loads during erection and

operation, and Lateral pressure.

DIFFERENT LOAD DATA Self load shall be determined by either actual measurement or in

accordance with IS 875 (Part I) the unit weight of wet concrete including reinforcement shall be taken as 26 kN/m². However, in absence of the data, load may be assumed as 500 N/M2 for the purpose of initial calculations .

Loads during constructional operation shall constitute the imposed loads [see IS 875 (Part 2 ) Where allowance has only to be made for access and inspection purposes, a loading of 750 N/m² should be adequate

The lateral pressure due to fresh concrete depends on the temperature of concrete as placed, the rate of placing of concrete and the concrete mix proportion

Wind loads should be taken for design in accordance with IS 875 (Part 3 ) subject to a minimum horizontal load equal to 3 percent of the vertical loads at critical level.

Snow loads should be assumed in accordance with IS 875(4) . The maximum density of ice may be assumed to be 900 kg/m³.

OUTPUT OF EXCEL SHEET(DOFW)