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M.E.

CONSTRUCTION ENGINEERING &

MANAGEMENT

“PREFABRICATED TECHNIQUE IN CONSTRUCTION INDUSTRY”

INTRODUCTION :

A Prefabricated structure is defined as a structure built through the

association and/or completion on site of several elements built in a

factory or assembled on site.

The concept of prefabricated construction includes those buildings,

where the majority of structural components are standardized and

produced in plants in a location away from the building, and then

transported to the site for assembly.

These components are manufactured by industrial methods based on

mass production in order to build a large number of buildings in a

short time at low cost.

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A multi storey building constructed with

Prefabricated Modular unitsA prefabricated modular unit being brought

to site for assembly

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FEATURES OF PREFABRICATED STRUCTURES

The division andspecialization ofthe humanworkforce.

The use of tools,machinery, andother equipment,usually automated,in the production ofstandard,interchangeableparts and products.

Compared to site-cast concrete,precast concreteerection is fasterand less affectedby adverseweather conditions.

Plant castingallowsincreasedefficiency, highquality controland greatercontrol onfinishes.

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FEATURES OF PFS (CONTD)

There is minimal work on site to complete the

buildings as the façade and interiors themselves

form part of units.

This type of construction requires arestructuring of entire conventionalconstruction process to enableinteraction between design phase andproduction planning in order toimprove and speed up construction.

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TYPES OF PREFABRICATION SYSTEMS

Large-panel

systems

Frame systems

Slab-column systems

with walls

Mixed systems

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LARGE PANEL SYSTEMS

The designation “large-panel system” refers to multistory structures

composed of large wall and floor concrete panels connected in the

vertical and horizontal directions so that the wall panels enclose

appropriate spaces for the rooms within a building.

These panels form a box-like structure. Both vertical and horizontal

panels resist gravity load.

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A large-panel concrete building under construction

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FRAME SYSTEMS

Precast frames can be constructed using either linear elements or

spatial beam-column sub-assemblages.

Precast beam-column sub-assemblages have the advantage that the

connecting faces between the sub-assemblages can be placed away

from the critical frame regions; however, linear elements are generally

preferred because of the difficulties associated with forming, handling,

and erecting spatial elements.

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FRAME SYSTEMS

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SLAB-COLUMN SYSTEMS WITH SHEAR WALLS

These systems rely on shear walls to sustain lateral load effects,

whereas the slab-column structure resists mainly gravity loads.

There are two main systems in this category:

Lift-slab system with

walls

Prestressedslab-

column system

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1. Lift-slab system with walls

In the Lift –slab system, the load-bearing structure consists of precast

reinforced concrete columns and slabs,. Precast columns are usually

two stories high.

All precast structural elements are assembled by means of special

joints.

Reinforced concrete slabs are poured on the ground in forms, one on

top of the other. Precast concrete floor slabs are lifted from the ground

up to the final height by lifting cranes.

The slab panels are lifted to the top of the column and then moved

downwards to the final position. Temporary supports are used to keep

the slabs in the position until the connection with the columns has

been achieved.

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A lift-slab building

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2. Prestressed slab-column system

The prestressed slab-column system uses horizontal prestressing in

two orthogonal directions to achieve continuity.

The precast concrete column elements are 1 to 3 stories high. The

reinforced concrete floor slabs fit the clear span between columns.

After erecting the slabs and columns of a story, the columns and floor

slabs are prestressed by means of prestressing tendons that pass

through ducts in the columns at the floor level and along the gaps

left between adjacent slabs.

After prestressing, the gaps between the slabs are filled with in situ

concrete and the tendons then become bonded with the spans.

Seismic loads are resisted mainly by the shear walls (precast or cast-

in-place) positioned between the columns at appropriate locations.

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PREFABRICATED CONCRETE STRUCTURAL ELEMENTS

Precast Slabs

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PREFABRICATED CONCRETE STRUCTURAL ELEMENTS

Precast Beam & Girders

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Precast Columns

PREFABRICATED CONCRETE STRUCTURAL ELEMENTS

Precast columns

Inverted Tee beams supported on precast columns

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Precast Walls

PREFABRICATED CONCRETE STRUCTURAL ELEMENTS18

Other Elements

PREFABRICATED CONCRETE STRUCTURAL ELEMENTS19

TYPICAL CONNECTION OF PFS

COLUMN TO COLUMN CONNECTION

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BEAM TO COLUMN CONNECTION

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SLAB TO BEAM CONNECTION

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PREFABRICATED STEEL STRUCTURE

Steel industry is growing rapidly in almost all the parts of the world.

The use of steel structures is not only economical but also

ecofriendly at the time when there is a threat of global warming.

Here, “economical” word is stated considering time and cost.

Time being the most important aspect, steel structures (Pre-

fabricated) is built in very short period and one such example is

Pre Engineered Buildings (PEB).

Pre-engineered buildings are nothing but steel buildings in which

excess steel is avoided by tapering the sections as per the

bending moment’s requirement. One may think about its

possibility, but it’s a fact many people are not aware about Pre

Engineered Buildings.

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A TYPICAL PRE-ENGINEERED METAL BUILDING

: Main Frame :

Primary Member

1. Column

2. Rafter

Secondary Members

1. Purlin

2. Girt

Sheeting

1. Roof

2. Wall

3. Fascias

Accessories

1. Ventilators

2. Sky Lights

3. Miscellaneous

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A Typical Pre-engineered Steel building

Advantage of Prefabricated Structures

The main advantages of prefabricated structures are assembly of

finished elements on site, self load bearing and quick execution.

Higher quality products for clients.

Improved productivity and profitability for contractors.

Environmental benefits associated with its use.

Quicker build times on site.

Better ability to build to optimum cost.

Higher quality end products due to closer factory control of part of

the process.

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Factory Building

Workshops

Showrooms

Schools

Industrial Sheds

Cold Storages

Office Buildings

Community Centers

Metro & Railway Station

Ware Houses

Distribution Centers

Aircraft Hangers

Sports Complex

Car Parking Sheds

Malls & SUPER Markets

Multistoried Buildings

Petrol Pumps

Application27

Industrial Building

Parking lots

Indoor Stadiums

Railway Station

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Aircraft Hangars Metro Station

Wear House High Rise Building

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Case Study30

Name of the Project : Anmol Spinex Pvt Ltd

Name of the Industry : Arvind Limited

Location of the Project : Satej, Ghandhinagar

Type of Project : Industrial Building

Area of Building : 18000 Sq.mt

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Anmol Spinex Pvt Ltd

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