This document provides details on the construction sequence and industrialized building system components for a 3 storey apartment building. It begins with an introduction to the building design which utilizes precast concrete and prefabricated timber framing. Section 2 describes the precast concrete and prefabricated timber systems to be used, including details on the fabrication process and types of components. Section 3 outlines the 14 step construction sequence. Section 4-6 provide drawings and details of the modular building components and construction.
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Building Technology 1
1. SCHOOL OF ARCHITECTURE, BUILDING & DESIGN
Bachelor in Science ( Honours) in Architecture
Building Technology 1
BLD 61403
Assignment 1 Industrialised Building System
Name :
Caleb Soh Er Wen
Lim Zanyu
Teh Sin Ying
Teo Chong Yih
Teo Vi Vien
Yong Man Kit
0320292
0325034
0320509
0314660
0321645
0319778
2. TABLE OF CONTENT
1.0 Introduction of Apartment
2.0 Concept and Framework
2.1 Precast Concrete
2.2 Prefabricated Timber
3.0 Sequence of Construction
4.0 Schedule of Modular Components
5.0 Drawings
5.1 Plans
5.2 Elevation
5.3 Sections
5.4 Isometric View
5.6 Details
6.0 IBS Score Calculation
3
4
5-13
14
15-20
21
22-29
30-33
34-35
36
37-43
44
4. In a group of 6, we were assigned to conduct a case study on an apartment built according to the IBS system. We’ve designed a 3 storey apartment in accordance to certain requirements of the
Malaysian Standard 1064. The apartment is designed in a modular system to increase the productivity on site, thus creating equally beautiful homes for the community when compared to the
conventional method of construction. Out apartment constitutes 3 storeys with 2 units per floor. As the building is considered low in most high rise buildings, homeowners are encouraged to walk
up to their respective units with the common staircase located at the centre of the building. A common garden forms a modern courtyard which enables better ventilation whilst encouraging
engagement and interaction between neighbour due to the interconnected common garden. The minimalistic design creates a calm and comfortable ambience, perfect for homeowners to relax
and unwind after a stressful day out.
INTRODUCTION
6. BENEFITS
Introduction to IBS
Introduced as a progressive alternative construction method, industrialised building system (IBS) describes a method of construction whereby building components are manufactured in
controlled and optimum environment , either on site or off site, before being transported and assembled into a structure with minimum work on site. In Malaysia, CIDB Malaysia through the IBS
Centre represents the main champion of the widespread usage of IBS with the ultimate goal of increasing productivity and quality at construction sites. These efforts are done categorically
through promotional programmes, trainings and incentives given based on the IBS Score of a building, determined based on the Construction Industry Standard 18.
INTRODUCTION
BENEFITS AND WEAKNESSES OF IBS
WEAKNESSES
COST
REDUCTION
HIGH AND CONTROLLED
QUALITY OF END
PRODUCT
SHORTER
CONSTRUCTION
PERIOD
LESS DEPENDENCY ON
FOREIGN WORKER
NOT AFFECTED BY
ADVERSE WEATHER
CONDITION
HIGH CAPITAL
COST
SOPHISTICATED PLANTS
AND SKILLED OPERATORS
SITE
ACCESSIBILITY
LARGE WORKING AREA
Due to minimized
wastage, a simplified
construction method,
requirement
Due to controlled
manufacturing environment
and common criteria of quality
building
Reduce the risk of project
delay and possible monetary
losses
reduced cash outflow from the
country Fabrication of the IBS components under
controlled environments ensures a smooth
construction process
Initial outlay to setup the IBS
production facilities is high
IBS requires adequate access to
transport all IBS components up to
the construction site
The equatorial climate in Malaysia which
experiences heavy rainfall can lead to the
problem of leakages
Construction projects using the IBS require
large work areas for the plants and storage
for the IBS components
7. 1
2.1.1 Introduction
Precast concrete is a commonly used IBS system in the modern construction industry due to the benefits that it brings to both contractors and clients likewise. As its name states, precast concrete
components are prefabricated off site in either a factory or controlled environment before being transported to site for assembly. Once delivered to site, lifting systems such as cranes are used to
erect the structure.
2.1.2 Fabrication Process
a) Normal Casting Fabrication Process
Used to manufacture precast reinforced or prestressed concrete components
1. The mould comprising of the base plate and side panels are assembled.
2. The leveling and flatness of the base mould should be inspected before assembling
the mould for casting
3. The dimensions of mould should be inspected to fall within the specified tolerance.
Assembly of mould
2.1 Precast Concrete System
2
1. The mould should be cleaned and free from debris and old mortars using remover
or scaling bars
2. Form oil or mould release agent should be applied evenly over the mould surfaces
3. The joints and edges of the mould, bolts, stoppers, tie rods, side props and rubber
seal are intact and properly secured.
Mould cleaning and preparation
8. 3
1. The rebar size, spacing and lap length need to be checked to ensure that it is done
according to the drawing.
2. Rebars, cast in-terms, corrugated sleeve pipes, recesses, lifting hooks and inserts
must be correctly positioned and properly secured.
3. Fabrication rigs may be utilised to ensure the accuracy of rebars fixing and spacing.
4. Tack welding may be carried out when necessary to secure these items.
Fixing of rebars / cast in items / prestressing strands
4
1. All details should be inspected to ensure compliance with drawings.
2. The mould fittings conditions including blackout details should be inspected.
Final Inspection before casting
2.1 Precast Concrete System
9. 5
1. The grade of concrete used must be inspected beforehand to ensure that it complies with
design specifications.
2. The concrete is poured into the mould continuously using the hopper until the entire mould is
filled.
3. Proper vibration and compaction should be carried out in particular at the areas which are
more congested.
4. Power trowel can be used to ensure a smooth surface finish.
Concreting
6
1. Adequate curing time in a desired environment should be observed
2. The components should be protected with tarpaulin or canvas to prevent rapid
moisture loss resulting in shrinkage cracks.
Curing
2.1 Precast Concrete System
10. 7
1. All bolts and pins, end and side mould forms should be loosened and removed before
lifting.
2. For prestressed components, strands should be cut before lifting.
3. Cube tests should be conducted to verify the concrete strength of elements before
demoulding.
Demoulding
8
1. Condition of the finished products should be inspected.
2. The critical dimension of the finished component should be verified.
3. Proper identification markings should be placed on components showing the
location, member type, size, weight and orientation as per drawing.
Final inspection / Transfer to storage / site
2.1 Precast Concrete System
11. 2.1.3 Types of Precast Concrete Components
a) Precast Reinforced Concrete Beams
The design of the building incorporates beams of three different cross sectional dimensions, corresponding to the expected total load to be supported. The cross sectional dimensions of
the beams are as following: ground beam (150mm x 600mm), floor beam (150mm x 450mm) and the roof beam (150mm x 300mm). The beams are connected to the columns using
L-anchors and all joints are finished with grouting.
All beams are reinforced with six steel rebars to provide improved compressive strength and adequate tensile strength.
2.1 Precast Concrete System
Isometric diagram of the beam-column connection + component
specification
12. b) Precast Reinforced Concrete Columns
The design of the building incorporates columns of two different dimensions, the standard columns (150mm x 300mm) and the part columns (900mm x 2100mm). Like all precast
components, it is manufactured offsite using a mould system. It is precast with either four or six steel rebars for additional compression and tensile strength. To better distribute the load and
support the superincumbent weight, corbels have been added to the precast columns.
Within this building design, there are two type of connections in relation to the columns. The aforementioned column-beam connection and also the column to column connection which is
achieved through a combination of metal bearing plates and embedded anchor bolts which are casted into the ends of the columns. The joint is then grouted for to ensure full bearing
between elements and protect against fire damage and corrosion.
2.1 Precast Concrete System
Isometric diagram of the column-column connection +
component specification
13. c) Precast Reinforced Concrete Half Slabs
The precast RC half slab system is a floor panel which represents a direct equivalent of an in-situ slab which combines both pre-cast and in situ concrete. It is usually between 75mm to
150mm thick and 1200mm to 2400mm in width. Upon installation, it is typically finished with a waterproof membrane, before another wire mesh is laid on as reinforcement for the cast
in-situ slab. In other words, it plays a dual function as both a permanent formwork as well as form part of the finished floor slab.
Using half slabs, as opposed to the typical full slabs, brings many benefits on top of that which comes with using IBS. These benefits are as such:
● Design flexibility
○ In-situ structural concrete topping forms a monolithic structure for efficient design
○ Irregular and complex shapes can be manufactured to cater to specific requirements
○ Service holes and cut-outs accurately formed during manufacturing process
2.1 Precast Concrete System
Isometric diagram of the completed half slab composition +
component specification
14. d) Precast Reinforced Concrete Stairs
The precast stairs is another component from the IBS which is designed to shorten the construction process and hopefully reduce the overall cost of construction. It is manufactured like
any other IBS, offsite and transported to site upon completion to be assembled thern. By utilizing precast staircase components, it will not only shorten the construction duration, but
also allow an immediate operational access to all floor areas.
It is connected to the slab via via tongue and groove joint. During the design stage, before prefabrication can began, two distinct architectural features must be incorporated into the
standard precast concrete staircase:
- Alignment of nosing of the first flight with the nosing of the adjacent flight to ensure a flush surface
- Simple and lined through intersection at the soffit of staircases where the flights and landings meet.
2.1 Precast Concrete System
Isometric diagram of the stairs + component specification
15. e) Precast Reinforced Concrete Wall Panels
The prefabricated wall panels are manufactured with the steel bar inlayed as reinforcement to support the lateral forces acting on the wall. The wall panels are connected to the beam
and columns via the use of tongue and groove connection and the joint is then grouted to seal and weatherproof the component, preventing corrosion or fire damage.
2.1 Precast Concrete System
Isometric diagram of the wall panel composition + connection
detail to slab and beams + component details
16. 2.2 Prefabricated Timber Frame
a) Prefabricated Timber Roof Truss
The roof truss is designed in the form of a Howe Girder truss. By having the component produced off site in a controlled and optimum environment, the workmanship and quality of
the timber frames can be improved and guaranteed to be of better standard, The finished trusses are transported to the site ready to be assembled onto the roof structure. It is
supported and braced with the purlins which also serve as the support for the roof surfaces which are the aluminium foil for thermal reflection and the outermost layer of metal
decking.
Isometric diagram of the prefabricated
timber frame + roofing materials
18. PRECAST
CONSTRUCTION
CONSIDERATION
All safety issues on site when
handling precast elements
The lifting capacity of the crane
used
The working boom-radius of the
crane
The suitability of construction
materials for the purpose of use
i.e sealant, grouting, shim plate,
propping etc.
Co- ordination with precaster
and specialist supplier to achieve
the best performance and
working method
Ensure the correct panel before
hoisting
Ensure the crane lifting capacity
before hoisting the panel
Ensure the desired crane's
working radius
Ensure the anchorage for the
propping does not damage
cast-in building services
Ensure the desired verticality/
position is achieved
Estimated time to install a typical
precast element is 1/2 to 3/4 hour
19. 3 4
21
1. Joining of Precast Concrete with Pile Cap 2. Grouting of Precast Concrete with Pile Cap
1. After the columns are mechanically joined the connection is grouted and formwork is
conducted.
2. The stump is made to provide full bearing between elements and protect the metal
components from fire and corrosion.
1. Precast concrete ground floor beams are connected to each other, and to the pile
caps, with small in situ concrete ‘stitches’
3. Installation of Precast Ground Beam 4. Installation of precast floor slab
1. The ground floor slab is lifted by using wire ropes (crane) and are placed and installed on
top of groud floor beam.
2. The joints are grouted solid.
1. The precast column is connected to the pile cap with anchor bolts by using the
bolted connection.
2. First, a shim plate or bearing plate is placed directly under the embedded steel
plate.
3. The column is placed on top of the embedded steel plate and the nut is screwed in
with the anchor bolt.
20. 7 8
5 1. The adjacent walls and plumb wall
corners are positioned at 200mm offset
2. The walls are adjusted verticality within
+2 or –2mm
3. The four faces of every walls are
adjusted
4. An string is positioned 250mm from the
face of the walls.
5. Walls within the same line are adjusted
within the same tolerance
6. Grouting is performed to seal all the air
pockets.
61. A layer BRC wire mesh is placed on top of the precast concrete slab for
reinforcement..
2. 75mm of of cast in situ concrete is poured on top for a smooth finish with visible
joints.
6. Setting up for precast wall installation
1. Setting reference line and offset line are
used to determine the position of the
precast wall to be installed.
2. The grid and marks of the wall position are
transferred on slab
3. A 100 mm offset line from rear building
edge is marked.
4. The wall is the offset by 200 mm.
5. A 2x2 timber is secured to the floor at wall
edge to guide the wall.
6. Shim plate will be placed on the floor and
leveled to the wall soffit.
7. Positioning of the wall
1. The precast concrete wall is lifted by using a crane and carefully installed on
the correct position by following the reference mark during the wall setting
procedure.
8. Wall Adjustment
5. Construction of second layer of reinforcement
cast in-situ concrete
21. 9
1. The beam is lifted by the crane and
moved above of the exact installation
position.
2. A piece of shim plate is placed to
correct the beam soffit level.
3. The beam is connected to the precast
columns by the anchor rebar.
4. The beam is hoisted in place and
checked from the top level.
5. The position on the floor is verified by
the plump beam.
6. The beam’s verticality is confirmed
with a spirit level.
7. The beam is then wedged against the
pockets and the gap between the
beam and the wall are grouted.
10
11 12
9. Installation of precast concrete beam
12. Installation of prefabricated timber roof trusses
10. Construction of subsequence stories
1. After the installation of the first floor beam, the placing of the first floor slab
has been carried out.
2. The construction sequence step 4 to step 8 has been repeated and carried
subsequently until the construction reached the final storey of wall panels
erected.
1. The prefabricated roof trusses are lifted
up by wire ropes (crane) and positioned
on top of the roof beams.
2. The positioning of the trusses is carefully
adjusted to the correct position.
3. The first truss is erected at one end.
After it is in the correct position,the truss
is nailed to the wall plates. The end
truss is then temporarily braced to the
ground at two places using timber.
4. Diagonal bracings are placed at an angle
of 45 ° to the trusses starting from the top
portion of the gable end truss to the
bottom portion of the fourth truss
11. Installation of the precast concrete staircase
1. The landing and slabs are positioned
and verified at soffit level at four
corners.
2. The level is adjusted within tolerance.
3. Shim plates are placed at the staircase
support location to the correct level.
4. Level differences between pegs on top
and below are verified.
5. The staircase is hoisted in place.
6. A10mm gap between the precast plank
and staircase is left for grouting.
22. 15 16
1413
14. Installation of roofing sheets
1. Roofing sheets are laid over the purlins.
The roofing sheets consist of corrugated
metal deck and aluminium foil sisalation
sheets.
15.. Installation of doors, windows and railing
1. As the installation of the roof is
completed, a dry interior environment is
presented.
2. The installation of doors, windows and
railings are carried out
16. Finishing
1. Lastly, the finishing work is the conducted
which included facing, plastering, flooring,
painting, wallpapering, and glazing.
13. Installation of roof purlins
1. Purlins are skew-nailed to each rafter with
two 76 mm nails, one on each side.
2. Fascia boards and barge boards are fixed to
the ends of rafters and purlins.
27. 1. Construction Area
i. Construction area of 1 unit apartment = 68.00m2
ii. Lobby area = 41.54m2
iii. Construction area for 1 floor = (68 x 2 units + 41.54
= 177.54m2
iv. Construction area of roof = 177.54m2
v. Total area = (177.54 x 4 storeys
= 710.16m2
2. Structural System
i. Beams : Precast concrete beam
ii. Columns : Precast concrete columns
iii. Floor slab : Precast half slab
iv. Roof truss : Prefabricated timber roof truss
3. Wall System
Internal wall : Precast concrete wall
External wall : Precast concrete wall
4. Other simplified construction solutions
I. Beam : 0% complies to MS 1064
Column : 92% complies to MS 1064
Door : 100% complies to MS 1064
Window : 100% complies to MS 1064
Wall : 82% complies to MS 1064
Slab : 0% complies to MS 1064
ii. Horizontal repetition of structure : 100%
Vertical repetition of structural floor layout : 100%
Repetition of floor to floor height : 100%
Elements Area (m2
) /
Length (m)
IBS factor Coverage IBS score
Part 1 : Structure Elements
Prefabricated timber roof truss 177.54m2
1.0 177.54 / 818.24
=0.22
0.22 x 1.0 x 50
= 10.85
Precast Column and Beam + Precast
Concrete Slab
710.16m2
0.6 710.16 / 818.24
=0.87
0.87 x 0.6 x 50
= 26.04
Total Part 1 818.24m2
1.09 36.89
Part 2 : Wall System
Internal wall : precast concrete panel
Total length = 54.9 x 4 storeys
219.6m 1.0 219.6 / 426.92
= 0.51
0.51 x 1.0 x 20
= 10.2
External Wall : precast concrete panel
Total length = 51.83 x 4 storeys
207.32m 0.5 207.32 / 426.92
= 0.49
0.49 x 0.5 x 20
= 4.9
Total Part 2 426.92m 1.00 15.1
Part 3 : Other Simplified Construction
Solutions
0% beam dimensions complies to MS
1064
0% 0
92% column dimension complies to MS
1064
96/104 = 92% 4
100% door sizes complies to MS 1064 100% 4
100% window complies to MS 1064 100% 4
97% wall complies to MS 1064 101.4/122.56 = 82% 4
0% slab complies to MS 1064 0% 0
Horizontal repetition to structure = 100% 100% 2
Vertical repetition of structural floor layout
=100%
100% 2
Repetition of floor to floor height = 100% 100% 2
Precast Toilet Pod 1
Precast Concrete Staircase 1
Total Part 3 24
IBS Contents Score pf Project (Part
1 + Part 2 + Part 3)
76
