prefabrication

1. OPEN PREFAB CONSTRUCTION SYSTEM
SUBMITTED BY :
ANUJ SINGHAL
GITANSHU
AVNISH
HARSHIT PANT
DIVYANSH
HIMANSHU CH.

2. What Is Prefabrication?
 Prefabrication is the practice
of assembling components of
a structure in a factory or
other manufacturing site,
and transporting complete
assemblies or sub-assemblies
to the construction site where
the structure is to be located.

3. AIMS OF PREFABRICATION
1. To speed up the construction time.
2. To lower the labour cost .
3. To ensure precise conformity to building codes , standards and greater
quality assurance.
4. To allow less wastage of materials than in site- built construction.
5. To ensure higher worker safety and comfort level than in site- built
construction
THE LIMITATIONS OF PREFABRICATION ARE:
1.A small number of units required may prove to be uneconomical
2. Special connections, such as special bearings to transmit the vertical and horizontal
loads, can add cost to the system
3. Waterproofing at joints
4. Transportation difficulties
5. Need for cranes

4. ADVANTAGES OF PREFABRICATION
 High quality product
 Labour related savings
 Savings in time
 Overall efficiency is greatly increased
 Mass production is easier and quick
 Protected and controlled production in
environment
 Potential for lower production costs and other
cost savings
 Independent climate conditions
 The disruption of traffic is avoided
 Ensures high degree of safety

5. CHARACTERISTICS ARE TO BE
CONSIDERED
 Easy availability
 Light weight for easy handling and
transport, and to economieson sections
and sizes of foundations;
 Thermal insulation property;
 Easy workability;
 Durability in all weather workability;
 Durability in all weather conditions;
 Non combustibility
 Economy in cost, and
 Sound insulation

6. DISADVANTAGES
 Carefull handling of prefabricated
components such as concrete panels or steel
and glass panels os required.
 Attention has to be paid to the strength and
corrosion- resistance of the joining of the
prefabricated sections to be avoid failure of
the joint
 Similarly, leaks can form at joints in
prefabricated components.
 Transportation costs may be higher for
voluminous prefabricated sections then for
the materials of which they are made, which
can often be packed more compactly.
 Large prefabricated sections required heavy-
duty cranes and precision measurement and
handling to placing position.

7. MATERIALS TO BE USED IN PREFABRICATED
SYSTEM
• Concrete
• Steel
• Treated wood
• Aluminium
• Cellular concrete
• Light weight concrete
elements
• Ceremic products etc

8. COMPONENTS OF PREFAB
CONSTRUCTION
Flooring and roofing schemes
Beams
Columns
Walls
Staircase
Lintels
Sunshade/chajja projection

9. VARIOUS PREFABRICATED CONSTRUCTION SYSTEMS
In conceptual dimension, prefabrication can be categorized as:
1.OPEN PREFAB SYSTEM:
This system is based on the use of the basic structural elements to form whole or part of a
building. The standard prefab concrete components which can be used are:
1. Reinforced concrete channel units.
2. Hollow core slabs
3. Hollow blocks and battens
4. Precast planks and battens
5. Precast joist and tiles
6. Cellular concrete slabs
7. Prestressed/ Reinforced concrete slabs
8. Reinforced / Prestressed concrete beams
9. Reinforced / Prestressed concrete columns
10. Precast lintels and chajjas
11. Reinforced concrete waffle slabs/ shells
12. Room size reinforced/ prestressed concrete panels
13. Reinforced / Prestressed concrete walling elements
14. Reinforced / Prestressed concrete trusses

10. CATEGORIES OF OPEN PREFEB SYSTEMS
 There are two categories of open prefab systems depending on the extent of
prefabrication used in the construction as given below:
 1. Partial prefab open system
 2. Full prefab open system
 Partial prefab open system: This system basically emphasizes the use of precast
roofing and flooring components and other minor elements like lintels, chajjas, kitchen
sills in conventional building construction. The structural system could be in the form
of in-situ framework or load bearing walls.
 Full prefab open system: In this system almost all the structural components are
prefabricated. The filler walls may be of bricks or any other local material.

11. PREFABRICATED HOUSING

12. Bridgetown, Barbados
EXAMPLES OF BUILDINGS WITH
PREFABRICATED CONSTRUCTION SYSTEM
McDonalds, UK
T30A Hotel Tower, China

13. NAKAGIN CAPSULE TOWER

14.  LOCATION: TOKYO, JAPAN
BUILDING STATISTICS-
• SITE AREA: 442 SQUARE METRES BUILDING
AREA: 430 SQUARE METRES TOTAL FLOOR
AREA: 3,091 SQUARE METRES.
• STRUCTURE DETAILS: STRUCTURAL STEEL
FRAME PARTLY ENCASED IN CONCRETE MAX
OF 140 CAPSULE UNITS (PREFABRICATED) 11-
13 STORIES INCLUDING 1 BASEMENT
• MATERIAL DETAILS: CAPSULE EXTERIOR:
STEEL WITH SPRAYED PAINT FINISH
CAPSULE INTERIOR: STEEL CAPSULE WITH CLOTH
CEILING AND FLOOR CARPET
TOWERS:CORTEN STRUCTURAL STEEL FRAME
LOWER
LEVELS: FAIR-FACED REINFORCED CONCRETE

15. • Methodology: Japanese Metabolism,
physical objects are never eternal,
celebrates individualism, response to
long commutes.
• Units of Prefabrication: Capsules
arrive from factory completely
prefabricated, ready to be lifted by
crane and bolted onto the
superstructure.
• Structure: Steel frame with lightweight
concrete shaft which houses
vertical circulation, mechanical shafts.
• Delivery: Dense urban surroundings
meant that capsules were delivered
from factory to site on the same day it
was attached to the superstructure

16. THE CAPSULE :
THE STEEL FRAME CAPSULES (WHICH
HAVE BEEN DESIGNED TO BE
REPLACEABLE, REMOVABLE, AND
TRANSPORTABLE) WERE PREFABRICATED
IN SPECIALIST FACTORIES AND
ASSEMBLED AT A PLANT BEFORE BEING
DELIVERED TO THE SITE. EACH ONE WAS
LIFTED BY MECHANICAL CRANES AND
WERE ATTACHED TO THE TOWER SHAFTS
USING 4 HIGH-TENSION BOLTS
THE CAPSULE INTERIOR WAS PREASSEMBLED
IN A FACTORY THEN HOISTED
BY CRANE AND FASTENED TO THE
CONCRETE CORE SHAFT.
DETAIL OF SYSTEM OF CAPSULE JOINING TO SHAFT

17. Capsule Delivery
1. Capsule Base Connections Détail
2. Capsule Bolting Process
3. Capsule Bolting Connection Detail
4. Prefabrication - 3 Hour Assembly
5. Transportation - 500km
6. Construction - 7-8 Months