1. PRECAST CONCRETE & PREFABRICATED TECHNOLOGY LIGHTWEIGHT CONCRETE CREATIVE PRECAST ... · 2018. 8. 31. · Precast architectural panels are also used to clad all or part of a building

TOPIC 2

PRECAST COMPONENTS OF IBS

1. PRECAST CONCRETE & PREFABRICATED

TECHNOLOGY

2. LIGHTWEIGHT CONCRETE

3. CREATIVE PRECAST PANEL

4. ESTIMATE SIZING OF COMPONENT USING

JKR-CIDB

DEFINITION OF PRECAST CONCRETE

AND

PREFABRICATED TECHNOLOGY

IN CONSTRUCTION INDUSTRIES

Precast concrete is a construction product

produced by casting concrete in a reusable mold or

"form" which is then cured in a controlled

environment, transported to the construction site

and lifted into place

http://en.wikipedia.org/wiki/Molding_(process)

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. The term is

used to distinguish this process from the more

conventional construction practice of transporting

the basic materials to the construction site where all

assembly is carried out.

http://en.wikipedia.org/wiki/Structurehttp://en.wikipedia.org/wiki/Factoryhttp://en.wikipedia.org/wiki/Manufacturinghttp://en.wikipedia.org/wiki/Transporthttp://en.wikipedia.org/wiki/Construction

Detached houses, cottages, log cabin, saunas, etc. are also sold with

prefabricated elements. Prefabrication of modular wall elements

allows building of complex thermal insulation, window frame

components, etc. on an assembly line, which tends to improve

quality over on-site construction of each individual wall or frame.

Wood construction in particular benefits from the improved quality.

However, tradition often favors building by hand in many countries,

and the image of prefab as a "cheap" method only slows its

adoption. However, current practice already allows the modifying

the floor plan according to the customer's requirements and

selecting the surfacing material, e.g. a personalized brick facade

can be masoned even if the load-supporting elements are timber.

http://en.wikipedia.org/wiki/Thermal_insulationhttp://en.wikipedia.org/wiki/Assembly_line

PREFABRICATED TECHNOLOGY

An example from house-building illustrates the process of

prefabrication. The conventional method of building a house

is to transport bricks, timber, cement, sand, steel and

construction aggregate, etc. to the site, and to construct

the house on site from these materials. In prefabricated

construction, only the foundations are constructed in this

way, while sections of walls, floors and roof are

prefabricated (assembled) in a factory (possibly with

window and door frames included), transported to the site,

lifted into place by a crane and bolted together.

http://en.wikipedia.org/wiki/Brickhttp://en.wikipedia.org/wiki/Timberhttp://en.wikipedia.org/wiki/Cementhttp://en.wikipedia.org/wiki/Sandhttp://en.wikipedia.org/wiki/Steelhttp://en.wikipedia.org/wiki/Construction_aggregatehttp://en.wikipedia.org/wiki/Prefabricated_buildingshttp://en.wikipedia.org/wiki/Foundation_(architecture)http://en.wikipedia.org/wiki/Wallhttp://en.wikipedia.org/wiki/Roofhttp://en.wikipedia.org/wiki/Crane_(machine)http://en.wikipedia.org/wiki/Screw

Prefabrication techniques are used in the

construction of apartment blocks, and housing

developments with repeated housing units. The

quality of prefabricated housing units had increased

to the point that they may not be distinguishable

from traditionally built units to those that live in

them. The technique is also used in office blocks,

warehouses and factory buildings. Prefabricated

steel and glass sections are widely used for the

exterior of large buildings.

http://en.wikipedia.org/wiki/Apartment

PRECAST CONCRETE

By producing precast concrete in a controlled

environment (typically referred to as a precast

plant), the precast concrete is afforded the

opportunity to properly cure and be closely

monitored by plant employees.

Utilizing a Precast Concrete system offers many

potential advantages over site casting of concrete.

The production process for Precast Concrete is

performed on ground level, which helps with safety

throughout a project.

There is a greater control of the quality of materials and

workmanship in a precast plant rather than on a construction site.

Financially, the forms used in a precast plant may be reused

hundreds to thousands of times before they have to be replaced,

which allow cost of formwork per unit to be lower than for site-

cast production.

There are many different types of precast concrete forming

systems for architectural applications, differing in size, function,

and cost. Precast architectural panels are also used to clad all or

part of a building facade free-standing walls used for landscaping,

soundproofing, and security walls, and some can be Prestressed

concrete structural elements. Stormwater drainage, water and

sewage pipes, and tunnels make use of precast concrete units.

http://en.wikipedia.org/wiki/Cladding_(construction)http://en.wikipedia.org/wiki/Facadehttp://en.wikipedia.org/wiki/Soundproofinghttp://en.wikipedia.org/wiki/Prestressed_concrete

VARIOUS STRUCTURES OF BUILDING

USING PRE-CAST CONCRETE

Concrete cast

into desired

shapes prior to

placement in a

structure

PRE-CAST CONCRETE

PRESTRESSED CONCRETE

ERECTION

The assembly of parts put together in

different ways to form the total building

fabric

The parts meet at joints or connections

Joint refers to the space between

components whether or not they are in

contact

FRAME JOINTS

PRECAST FRAME JOINTS

PREPARATION METHOD OF PRECAST

CONCRETE

The main factor that contributes to the

success of a precast building project is

‘integration’ of all building professionals

(include architects, engineers, clients,

contractors and subcontractors).

The following figures illustrate the precast

concrete process:

1. Production of reinforced cages and main connections:

The precast factory often

has specialist workshops

for the manufacture and

maintenance of moulds,

and for the production of

jig-built reinforcing cages

and connections.

http://theconstructor.org/practical-guide/material-testing/concrete-material-testing/


concrete process:

2. Assembly of moulds:

The reinforced cage is

positioned in the partly

assembled mould, then

the remaining mould

section is completed.



concrete process:

3. Mix being poured:

Carefully specified

concrete is placed into

the mould. Many

precast works now

employ computer

controlled batching

plants.



concrete process:

4. Compaction of concrete using poker vibrator:

To ensure that optimum

density is obtained and

that specified strengths

are achieved, concrete

is placed and compacted

using high-frequency

external vibrators or

pokers.



concrete process:

5. Precast concrete being moved to the storage area:

Once an appropriate strength has

been reached, the precast units are

moved to the storage area. Units

are usually handled within hours of

casting as part of the rapid

production cycle.

The product exhibits a high degree

of dimensional accuracy and quality

of finish. Economies of production

are achieved through the repetitive

and automated process.

http://theconstructor.org/practical-guide/material-testing/concrete-material-testing/http://theconstructor.org/concrete/precast1/


concrete process:

6. Storage of high-quality units in works area:

The finished precast

components are stacked on

clean battens or plastic pads

positioned to suit the design of

the component. Care is taken

to keep the stacks vertical and

to ensure that battens are

placed directly above one

another within the stack.



concrete process:

7. Transport to site:

The components are

delivered to site in a

pre-determined

sequence to ensure that

hardened concrete are

ready for instant

erection.

http://theconstructor.org/practical-guide/material-testing/concrete-material-testing/http://theconstructor.org/concrete/special-concrete/hardened-concrete1/


concrete process:

8. Erection at site:

The components are

erected straight from

the lorry. This leads to

faster erection times

with reduced on-site

activity.



concrete process:

9. Finished building:


ADVANTAGES &

DISADVANTAGES OF

PRECAST CONCRETE

SYSTEM & PREFABRICATED

TECHNOLOGY

IN CONSTRUCTION

INDUSTRIES

ADVANTAGES OF PRE-CAST CONCRETE

SYSTEM & PREFABRICATED TECHNOLOGY

High level mechanization thus precisionNo delay due to bad weather and manpower (Independent of

adverse weather conditions during construction)Application of modular design in standardizing dimensions Work done concurrently at factory and at site thus speed

up constructionLow site workers requirement due to simplified

construction methodsQuality controlled and highly aesthetic end productsReduction of construction materials at sitesSave costs

Reduction / elimination of conventional timber formworks

Reduction / elimination of props

Reduction of construction wastes

Cleaner sites

Safer construction sites

Faster completion of construction projects

Cheaper total construction costs made possible due to all of the

above

Environmental friendly way of building, with optimum use of

materials, recycling of waste products, less noise and dust etc.

Continuing erection in winter time until -20 °C

DISADVANTAGES OF PRE-

CAST CONCRETE SYSTEMLeaks 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.

EXAMPLES: IBS

The construction of Police Station

in Senawang Negeri Sembilan:

Comprises of 1 unit of Police

Station Office Block, 4 units of Class

F Quarters and 2 Units of Class G

Quarters and the External works

THE CONSTRUCTION OF QUARTERS G

The Block comprises of 5 Storey Building as shown in the picture

QUARTERS G

Precast Wall Precast Slab

Level Block G1

Block G2

Block G1

Block G2

1 91 91 0 0

2 94 94 102 102

3 94 94 102 102

4 94 94 102 102

Upper Roof

1 1 0 0

468 468 408 408

NUMBERS OF PANELS USED

CONSTRUCTION PROCESS USING PRECAST PANELS

PILING

PILE CAP

STUMP

GROUND BEAM

FLOOR SLAB

COLUMN

INSTALLATION OF CONCRETE WALL PANEL

INSTALLATION OF FLOOR SLAB CONCRETE PANEL

CONCRETE TOPPING ON FLOOR SLAB

PROCESS REPEATED FOR SUCCESIVE FLOOR

cast insitu

cast insitu

cast insitu

cast insitu

precast

precast

cast insitu

OTHER EXAMPLE OF PRECAST

CONCRETE PANELS CONSTRUCTION

Construction of Quarters in Audit Academy in

Negeri Sembilan

More Types of Precast Panels were used in the

construction

Hollow Core Slab 1927.0 m2

Precast Plank291.0 m2

Precast Balcony 16 nos.

Precast Beam 136 nos.

Precast Column 63 nos.

Precast Staircase

(Flight & Landing Elements)12 nos.

Precast Parapet & Load

Bearing Walls200 nos.

Components delivered for this project are as below:

SOME COMPLETED PROJECT PHOTOS USING PRECAST CONCRETE STRUCTURE

-Commercial Building Category

SOME COMPLETED PROJECT PHOTOS USING PRECAST

CONCRETE STRUCTURE

-Public Building Category

TOPIC 2CREATIVITY PRECAST PANELS FOR INDUSTRIALISED BUILDING SYSTEM (IBS)

INTRODUCTION OF PANELS SYSTEM

DEFINE AS PREFABRICATED EXHIBIT COMPOSED OF

CONNECTED RECTANGULAR PANELS OF VARIOUS

SIZES.

MADE IN VARIOUS FORMS AND NORMALLY

PREFABRICATED AT FACTORY.

CONTRIBUTED ONLY FOR AESTHETICAL EXPRESSION OF

BUILDING.

Light and medium weight panel

•Wood frame

•Metal frame

•Composite materials

Heavy weight panel

(factory produced)

•Concrete

Heavy weight

panel (tilt up-

produced on site)

•Concrete

PANEL SYSTEM

PANELS WITH FALSE COLUMN

False column are simple column provided at the opening side of the

door.

Simply bind at grade beam or at roof rods.

PANELS WITH CURVE PANEL

Is a special panel having big dimensions and thickness.

Manufactured in the factory in a flat form and pre arranged in order

to be bent after the job site.

Main advantage offered by this panel is possibility to cover big areas

in a fast and convenient way.

The structure grants a high thermal insulation as well as a resistance

to earthquakes.

PANEL WITH DECORATIVE OPENING

DECORATIVE OPENING

Are widely used in modern interior decoration.

The example are wave panel, decorative grille and

acoustic panel.

They have 3D effect, suit for all types of interior design

concepts.

Wooden acoustic panel is excellent at reducing

noises.

PANEL WITH CAST-IN ALUMINIUM WINDOW FRAME

The implementation of cast-in window system requires coordination

between the window fabricator and the precaster.

Proper handling and protection are important throughout the

precast process, delivery and erection of the precast wall panels.

Protection is importance to avoid physical damages to the frames,

which could be costly to rectify or replace.

PANEL WITH CORNICE

Cornice are generally found at the very top of an exterior wall, just under the roofline.

Define as any horizontal decorative molding that crowns a building or furniture elements.

The function is throw rainwater free of the building wall and increase aesthetic value of the building.

Cornices can be used both inside a building and outdoors. While outdoor cornices tend to be functional in moving water away from the home, indoor varieties tend to be strictly decorative

FACADE

• One side of the exterior of a building,

especially the front (frontage) but also

sometimes the side and rear of building.

• Is the outer appearance which is forecasted

to make the viewers or observers believe

that the thing behind the outer appearance

will be as good as the outer appearance.

• Two categories:-

1) Load bearing façade

2) Non load bearing facade

Load bearing facade

Façade which serve dual purpose as structural supports for floor load,

structural above or architectural element.

Non Load bearing facade Build as decorative enclosures for internal floors. Often used as

skeletal frames (steel, precast in-situ)

PRECAST STAIRCASE,

BATHROOM AND HALF

SLAB

PRECAST STAIRCASE

The stair units are precast reinforced concrete modular stairs used in layouts which are

individually designed to suit the client’s requirements.

Manufactured in sections specifically designed to be manhandled.

This system suited to all types of buildings, including residential, commercial and industrial

applications e.g. townhouses, clusters, offices, houses, low-cost housing and fire escapes.

PRECAST STAIRCASE

Advantages of precast staircase:-

i. Expert advice, professional service and prompt delivery.

ii. Quality, uniform product

iii. Flexibility

iv. The advantages of a dry trade

v. The elimination of formwork enables instant access and use of stairs.

vi. Tiles laid directly onto stairs

PRECAST STAIRCASE

Advantages of precast staircase:-

vii. Balustrades can be fixed to either the top or side of the stairs

viii. Rapid installation

ix. Cost savings on material, time and labour

PRECAST STAIRCASE

BATHROOM

In spite of the fact that bathroom is one of the smallest rooms of a house,

it is one of the most labour intensive elements for construction, asking for

proper waterproofing and careful quality control.

Benefits of pre-fabricated bathroom units are reviewed as:

i. Higher quality finishes and low wastage of materials,

ii. Improved productivity of labour on site,

iii. Reduced wet work especially in the bathroom and less cleaning up work

on site,

iv. Better quality in waterproofing works in the factory environment,

v. Maintenance can be carried out within the unit rather from neighbouring

unit,

vi. High buildability score.

BATHROOM

These benefits translate into substantial savings in cost for developers,

high and consistent quality product for designers and simpler quality

control for contractors.

HALF SLAB

Comprise a thin reinforced precast concrete slab with cast in lattice girders and which are provided with

an in-situ concrete topping.

Suitable as floorings for building, bridge decks, and permanent formworks.

HALF SLAB

Under the Construction Industry Master Plan (I Master Plan 2006-2015), Malaysia’s

construction sector is envisioned in 8 years time to be a highly efficient and productive

industry.

By 2015, it should be an industry that employs highly skilled workers adapt at utilizing

modern techniques and technology which can deliver high quality products and services.

IBS was well known in many developing countries as it provides high level quality

construction, more cost competitive, rapidly increases construction period, reduces

dependence on foreign labor, reduces wastage, environmental-friendly and maintains

cleanliness at construction sites.

Based on statistics provided by the Department of Statistics (DOS), the used of timber and

timber products as construction materials for 2010 was valued at RM 4.02 billion which

comprised mainly of sawn timber RM 2.46 billion (61.3%), plywood (water proof) RM 689

million (17.2%) timber door and window frame RM 464 million (11.6%) and other timber

materials RM 333 million (8.3%) and gypsum plaster board RM 66 million (1.6%).

Out of which, a value of RM 86 million (13.6%) was IBS timber frames (prefabricated timber,

beams and column).

Source :- MTIB-CIDB

WOOD & TIMBER PRODUCT

RM

4,015,784,000

(82.4%)

IBS WOOD MATERIALS

RM 85,514,000

(17.6%)

APPLICATION OF TIMBER IN

CONSTRUCTION INDUSTRY

FLOORING

ROOF TRUSSES

COLUMN

INSTALLATION OF GLULAM GALLERY

AT JOHOR BHARU

ENGINEERED TIMBER PRODUCT (ETP)

GLUED LAMINATED TIMBER

(EDEN PROJECT, UK)LAMINATED VENEER LUMBER

Timber IBS is still at infant state in Malaysia.

Currently there are 21 licensed fabricators of

Timber IBS. Number of CIDB registered as supplier

for timber IBS is far lesser than other IBS material.

The use of timber is construction is gradually being

eroded by alternatives materials such as steel,

concrete and PVC, hence timber IBS is not

considered as a competitive sector.

Lack of appropriate education to specifiers and

consumers in the use of our timber resources which

caused a negative perception on local timbers.

STRUCTURAL LIGHTWEIGHT

CONCRETE (LWC)

Lightweight concrete can be defined as a type ofconcrete which includes an expanding agent in that itincreases the volume of the mixture while givingadditional qualities and lessened the dead weight.

It is lighter than the conventional concrete.

The use of lightweight concrete has been widely spreadacross countries such as USA, United Kingdom andSweden.

The MAIN SPECIALTIES of lightweight concrete are its lowdensity and thermal conductivity.

It’s ADVANTAGES are that there is a reduction of dead

load, faster building rates in construction and lower

haulage and handling costs.

It was first introduced by the Romans in the second century

where ‘The Pantheon’ has been constructed using pumice,

the most common type of aggregate used.

The building of ‘The Pantheon’ of lightweight concrete

material is still standing eminently in Rome until now for

about 18 centuries as shown in Figure . It shows that the

lighter materials can be used in concrete .

THE

PANTHEON

Lightweight concrete CAN BE PREPARED either by injecting

air in its composition or it can be achieved by omitting the

finer sizes of the aggregate or even replacing them by a

hollow, cellular or porous aggregate.

Lightweight concrete can be categorized into three groups:-

i) No-fines Concrete

ii) Lightweight Aggregate Concrete

iii) Aerated/Foamed Concrete

No-Fines Concrete

Defined as a lightweight concrete composed of cement

and fine aggregate.

Uniformly distributed voids are formed throughout its

mass.

It maintains its large voids and not forming laitance

layers or cement film when placed on the wall.

The strength of no-fines concrete increases as the

cement content is increased.

It is sensitive to the water composition.

Lightweight Aggregate Concrete

• The porous lightweight aggregate of low specific gravity is usedin this LWC.

• Can be natural aggregate such as pumice, scoria & all of thosevolcanic origin and artificial aggregate.

• There are 2 types of lightweight aggregate concrete:-

i. Compacted lightweight aggregate concrete (for precastconcrete blocks or panels, cast in-situ roofs and walls)

ii. Structural lightweight aggregate concrete (can be used withsteel reinforcement as to have a good bond between the steeland the concrete.

Aerated / Foamed Concrete

Does not contain coarse aggregate, and can be regarded as an aerated mortar.

Is made by introducing air or other gas into a cement slurry and fine sand.

In commercial practice, the sand can be replace by pulverized fuel ash, or

siliceous material or lime as cement.

There are 2 methods to prepare the aerated concrete:-

i. Inject the gas into the mixing during its plastic condition. (for precast units at

factory)

ii. Air is introduced either by mixing-in stable foam or by whipping-in air, using

an air-entraining agent. (for in-situ concrete)

Water Absorption

Water absorption is an important factor due to

the porous structure of the aerated

lightweight concrete.

The water absorption test is done using the

samples prepared at the age of 28 days.

The purpose of this test is to identify the

capability of the concrete to absorb water.

Entrained Air

As with normal-weight concrete, entrained air in structural

lightweight concrete ensures resistance to freezing and thawing

and to deicer applications.

It also improves workability, reduces bleeding and segregation, and

may compensate for minor grading deficiencies in the aggregate.

The amount of entrained air should be sufficient to provide good

workability to the plastic concrete and adequate freeze-thaw

resistance to the hardened concrete.

Air contents are generally between 5% and 8%, depending on the

maximum size of coarse aggregate used and the exposure

conditions.

PRODUCTION OF LWC

APPLICATIONS

Lightweight concrete has been used since the eighteen

centuries by the Romans.

The lightweight concrete was also used in construction during

the First World War. The United States used mainly for

shipbuilding.

It is widely used as loose-fill insulation in masonry construction

where it enhances fire ratings, reduces noise transmission,

does not rot and termite resistant.

It is also used for vessels, roof decks and other applications.

ADVANTAGES

Rapid and relatively simple construction.

Economical in terms of transportation as well as reduction in manpower.

Significant reduction of overall weight results in saving structural frames,

footing or piles.

Most of lightweight concrete have better nailing and sawing properties than

heavier and stronger conventional concrete.

Reduction in dead loads making savings in foundations and reinforcement.

Improved thermal properties.

Improved fire resistance.

Reduction in formwork and propping.

DISADVANTAGES

Very sensitive with water content in the mixtures.

Difficult to place and finish because of the porosity

and angularity of the aggregate. In some mixes the

cement mortar may separate the aggregate and

float towards the surface.

Mixing time is longer than conventional concrete to

assure proper mixing.

Documents

1. PRECAST CONCRETE & PREFABRICATED TECHNOLOGY LIGHTWEIGHT CONCRETE CREATIVE PRECAST ... · 2018. 8. 31. · Precast architectural panels are also used to clad all or part of a building