2. 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.
2
3. A multi storey building constructed with
Prefabricated Modular units
A prefabricated modular unit being brought
to site for assembly
3
4. FEATURES OF PREFABRICATED STRUCTURES
The division and
specialization of
the human
workforce.
The use of tools,
machinery, and
other equipment,
usually automated,
in the production of
standard,
interchangeable
parts and products.
Compared to site-
cast concrete,
precast concrete
erection is faster
and less affected
by adverse
weather conditions.
Plant casting
allows
increased
efficiency, high
quality control
and greater
control on
finishes.
4
5. 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 a
restructuring of entire conventional
construction process to enable
interaction between design phase and
production planning in order to
improve and speed up construction.
5
6. TYPES OF PREFABRICATION SYSTEMS
Large-
panel
systems
Frame
systems
Slab-
column
systems
with walls
Mixed
systems
6
7. 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.
7
9. 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.
9
11. 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
Prestressed
slab-
column
system
11
12. 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.
12
14. 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.
14
23. 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.
23
24. 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
24
26. 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.
26
27. 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
Application
27
30. Case Study
30
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
