Prefab

PRE-FABRICATION

SUBMITTED BY- RAJAT SINGH MOHAK JAIN SIDDHARTH ATREYA MEHJABEEN SULTHANA MOHIT RAJ NITESH KANNAUJIA RISHABH KAUSHIK

Pre-FabricationIt 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.

Definitions

Pre-Fabricated ConstructionA construction method relying primarily on the use of standardized

manufactured components; consists largely of assembling these

parts rather than fabricating them at the site.

Pre-Fabricated House A house assembled from components cut to size at a factory,

or assembled from building modules shipped to the

construction site.

Pre-Fabricated Masonry Panel A wall panel fabricated of masonry units which are bonded

together at a manufacturing plant and then transported to the

job site as a construction unit, ready for erection.

HISTORY

Buildings have been built in one place and reassembled in another throughout history. the first advertised prefab house was

the Manning Portable Cottage.

A London carpenter, Henry Manning, constructed a house that was built in components, then shipped and assembled by British

emigrants.

In Barbados the Chattel house was a form of prefabricated building which

was developed by emancipated

slaves who had limited rights to build

upon land they did not own.

As the buildings were

moveable they were

legally regarded aschattels.

In 1855 during the Crimean War, after Florence Nightingale wrote a letter to The Times, Isambard Kingdom Brunel was commissioned to design a prefabricated modular hospital.

In five months he designed a 1,000 patient hospital, with innovations in sanitation, ventilation and a flushing toilet.

Prefabricated housing was popular during World War II due to the need for mass accommodation for military personnel. The United States used Quonset huts as military buildings, and in the United Kingdom prefabricated buildings used included Nissen huts and Bellman Hangars.

HISTORY

McDonalds uses prefabricated structures for their buildings, and set a

record of constructing a building and

opening for business within 13 hours on

pre-prepared ground.

In the UK, the major supermarkets have each developed a modular unit system

to shop building, based on the systems

developed by German cost retailers Aldi

and Netto.

HISTORY

Fabricated UnitFabricated are typically made of extruded or

poured metal (aluminum or steel) The units

range in scale from a small fasteners to steel

bridge trusses. For the consideration of

construction and design logics, metal

fabricated components from the single stud to

the 300-0 bridge truss are in this category.

Panel SystemPanel systems contain integrated systems

within one component. Often included are

structural, thermal/waterproofing, electrical,

mechanical systems. Made up of a sandwich of

complementary materials. How the panels are

handled on site is dependent on the weight and

size of each piece.

Precast ConcretePrecast concrete is fabricated in a multitude

of sizes. Precast components are comprised

of an internal steel rebar framework and high

tolerance concrete. Concrete is meant to

withstand transport to and movement on site.

Units are limited in weight and dimensions

based on the smallest unit of transportation

Definitions

Steel Frame Construction

Fabricated Units compose the structural framing.

Fabricated Unit Logic

Panelized construction minimizes on-site

construction. Construction materials typically

fastened on-site are compiled into a component

constructed in the controlled factory environment.

Most common type of panel system is SIPs,

structural insulated panels.

SIPs are comprised of a thick layer of insulation

between two layers of OSB, oriented strand board. A

basic SIPs panel is composed of both structure and

insulation layer.

Panel systems may increase material cost by up to

50% but on-site labor cost can potentially decrease

by 50%. The benefit exists in the precision of factory

controlled construction with isolation from problems

that exist at the site.

Installation of the panels is based on methodology

developed for the specific system.

Panel Installation Sequence

Different systems will have

different advantages: whether the

panel is lightweight or resistant to

weather, earthquakes, winds,

insects, debris.

PANEL System

Precast concrete construction is most readily

seen within the city as infrastructure. It is a

versatile construction type.

Composition of Precast

Materials and Accessories

Rebar concrete: portland cement, water,

air, aggregate

Formwork:

positive/negative connection keys

Epoxy cementitious grout:

between precast segments/ components.

Structural Components

Slabs

length factor by function of service

width by transportation restriction

Beams

depth is dependent on length

length is function of capacity load

Columns

height is dependent on the width1. Solid

2. Hollow Core

3. Single Tee

4. Double Tee

5. Rectangular

6. Inverted Tee

7. L-shaped

8. Round|Rectangle

9. Square

10. Double Height

PRECAST CONCRETE

Process

Advantages of Prefabrication High capacity- enabling the realization of important projects

Factory made products

Shorter construction time- less than half of conventional cast in situ construction

Independent of adverse weather conditions during construction

Continuing erection in winter time until -20 C

Quality surveillance system

Opportunities for good architecture

Healthy buildings

Reduced energy consumption

Environmentally friendly way of building with optimum use of materials, recycling of waste products, less noise and dust etc.

Cost effective solutions

Disadvantages of Prefabrication Leaks can form at joints in prefabricated components.

Transportation costs may be higher for voluminous prefabricated sections than for the materials of which they are made, which can often be packed

more efficiently.

Large prefabricated sections require heavy-duty cranes and precision measurement and handling to place in position.

Larger groups of buildings from the same type of prefabricated elements tend to look drab and monotonous.

Local jobs may be lost, if the work done to fabricate the components being located in a place far away from the place of construction. This means that

there are less locals working on any construction project at any time,

because fabrication is outsourced

EXAMPLES of Prefabrication

NAKAGIN CAPSULE TOWER

T30A HOTEL TOWER

GFRG Demo Building at IIT Madras

NAKAGIN CAPSULE TOWER 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

.

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 light-

weight 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


THE STRUCTURE :

REPUTED TO BE THE WORLDS FIRST STRUCTURE THAT IMPLEMENTED THE INNOVATIVE IDEA OF

CAPSULE ARCHITECTURE, KISHO KUROKAWA

DESIGNED THE NAKAGIN CAPSULE TOWER BASED

OFF OF HIS SUSTAINABILITY CONCEPT CALLED

METABOLISM.

THE NAKAGIN CAPSULE TOWER IS A MIXED-SYSTEM STRUCTURE, UTILIZING BOTH TRADITIONAL ARCHITECTURE WITH MODERN

TECHNOLOGY WITHIN ONE ENTITY. IT IS MADE OF

TWO REINFORCED CONCRETE AND STEEL FRAME

PILLARS OF ASYMMETRIC HEIGHTS, BOTH HOUSING

PUBLIC UTILITIES SUCH AS STAIRS, ELEVATORS,

PLUMBING, AND ELECTRICAL SYSTEMS .

THE 14-STORY HIGH TOWER HAS 140 CAPSULES

STACKED AT ANGLES AROUND THE CENTRAL CORE.

KUROKAWA DEVELOPED THE TECHNOLOGY TO

INSTALL THE CAPSULE UNITS INTO THE CONCRETE

CORE WITH ONLY 4 HIGH-TENSION BOLTS, AS WELL

AS MAKING THE UNITS DETACHABLE AND

REPLACEABLE.


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 PRE-

ASSEMBLED IN A FACTORY THEN HOISTED

BY CRANE AND FASTENED TO THE

CONCRETE CORE SHAFT.

DETAIL OF SYSTEM OF CAPSULE JOINING TO SHAFT


THE CAPSULE :

Capsule Axonometric

1. Plumbing, Electrical, & Waste Lines

2. Vertical Plug-In Service Fin

3. Air Conditioning Duct

4. Air Conditioning Register

5. Prefabricated Bathroom

6. Built-In Desk

7. Moveable Chair

8. Built-In Bed


Typical Capsule Plan 1. Capsule Entrance

2. Prefabricated Bathroom

3. Air Conditioning Chase

4. Interior Finish Surface

5. Welded Light-Weight Steel Truss Member A6. Welded Light-Weight Steel Truss Member B7. Built-In Bed

8. Circular Window


The capsules contained a built-in bed and

drop-in bathroom unit. They were outfitted off

site and hoisted into place by crane, latching

onto the fourteen-story superstructure and its

concrete shaft of vertical circulation. All

capsules were driven in by truck the same

day they were to be plugged-in. A stop-over happened on the outskirts of Tokyo where

the capsules got transferred to smaller

trucks.

HE BORROWED THE CAPSULE TERMINOLOGY FROM THE AEROSPACE INDUSTRY (ALREADY AWARE THAT

MANY SPACESHIPS HAVE IMPLEMENTED THE IDEA OF

EFFICIENT AREA-USAGE) AND RETROFITTED A

RECTANGULAR CABIN OF 8 FEET BY 12 FEET FLOOR

SPACE WITH A BUILT-IN BATHROOM, DOUBLE BED,

DESK, STORAGE SPACES, TV, TAPEDECK,

TYPEWRITER, CALCULATOR, CLOCK RADIO, AND A 2-

BURNER STOVE. IT WAS PLANNED AS A FUTURISTIC

NICHE FOR MODERN BUSINESSMEN IN TOKYO.


KUROKAWAS DESIGN CONCEPT FOCUSES ON HOW TO MAKE

THE MOST EFFICIENT USE OF

LIVING SPACE TO

ACCOMMODATE THE EVERYDAY

ESSENTIALS OF A PERSON.

INSIDE THE CAPSULE

(2.5M X 4.5 X 2.5M) :

Exploded Axonometric

1. Precast Concrete Shell w/ Steel Frame

2. Plug-In Service Fins

3. Lightweight Precast Concrete Floor Plates

4. Precast Concrete Lift Shaft

5. Ground Level Podium - Office Space

Armature: a framework to support the clay or other

material used in modelling.

The tower is comprised of two, interconnected towers

which serve as the framework for the capsules to rest

on. The on-site preparation work to create the armature

is the first stage.

The Armature Components

Components: Plan & Core

1. Typical Capsule

2. Lightweight Precast Concrete Floor Plate

3. Prefabricated Interim Bridge

4. Plug-In Service Fin

5. Precast Concrete Shell w/ Steel Frame

6. Prefabricated Lift Cage

7. Typical Floor Entrance/Exit

Aggregation: Type 1

1. Typical Side-Entry Capsule w/ Side Window

2. Typical Front-Entry Capsule w/ Side Window

3. Side Window Capsule Aggregation

Aggregation: Type 2

1. Typical Side-Entry Capsule w/ End Window

2. Typical Front-Entry Capsule w/ End Window

3. End Window Capsule Aggregation

The Aggregation & Capsule Delivery


Type 1

Type 2

Capsule Delivery 1. Capsule Base Connections Dtail

2. Capsule Bolting Process

3. Capsule Bolting Connection Detail

4. Prefabrication - 3 Hour Assembly

5. Transportation - 500km

6. Construction - 7-8 Months


TIME LINEThe precast concrete floor slabs that were part of the

cores structure were erected at a rate of one every two days, alternating with the construction of the steel frame,

affording a full operational core to facilitate the periodic

construction of the framework without an external

scaffold. 144 capsules were attached to the building in

less than a month. Interestingly, the podium, which is the

most under-looked part of the project, had more

traditional construction techniques and also responsible

for much of the on-site construction time.

T30A HOTEL TOWER

LOCATION- CHANGSHA, CHINA HEIGHT: 99.9 meter / 328 feet FLOORS- G+30 GROUND FLOOR AREA- 17,602 m / 189,466 ft OWNER/DEVELOPER- BSB GROUP

(BROAD SUSTAINABLE BUILDING)

BUILDING FUNCTION- HOTEL STRUCTURAL MATERIAL- STEEL

A 3.915.6m main board including flooring and ceiling, embedded shafts of ventilation,

water supply & drainage, electricity and

lighting. All needed pillars, diagonal bracings,

doors, windows, walls and even sanitary &

kitchen wares for the room installation are

placed on main board for factory shipment.

One truck can carry 120m2 main boards and

then deliver them to the construction site to

be hoisted in installation place. What all

workers need to do is just screwing bolts,

painting. Such a high-efficiency construction

mode makes on-site installation only account

for 7% of the total construction hours. This

building is 93% factory-made.

T30A HOTEL TOWER

T30A HOTEL TOWER

THE INSTANT SKYSCRAPER

T30A HOTEL TOWER

GFRG demo building at IIT Madras (1981 sq ft)



TYPICAL FLOOR PLAN

BUILT UP AREA-1981.3 SQ. MT.

Date post:	15-Oct-2015
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