Industrialized Building System

PRECAST CONCRETE SYSTEM Project 1: Industrialised Building System (IBS) BUILDING TECHNOLOGY I Tutor: Mr. Khairool Group Members: Charlotte Chin Ya-Le Nurul Rihana Lin Shan En Peh Ellyn Neo On E

0326940 0326468 0331085 0326812 0326727

content 1

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introduction

precedent study

technical drawings

schedule of IBS components

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construction details & process

IBS score calculation

conclusion

reference

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1.1 1.2 1.3 1.4 1.5 1.6

Introduction to IBS Types of IBS in Malaysia Advantages & disadvantages of IBS Standard IBS design workow Precast concrete system Case studies

01 introduction

1.1

Introduction to IBS

Industrialised building system (IBS) is a term used in Malaysia for a technique of construction where by components are manufactured in a controlled environment, either at site or off site, placed and assembled into construction works, with minimal site work. IBS consists of construction components such as precast components, formwork system, fabricated steel framing system, modular block systems and prefabricated steel framing structures.

The Construction Industry Development Boards (CIDB) was formed in 1994 and since then, they have been actively promoting the usage of IBS to the local construction industry. In the same time, they educate contractors with the concept of IBS functioning as “assemblers of components” instead of “builders”. CIDB has implemented the IBS Score System into the construction industry to measure the level of IBS usage in buildings.

The implementation of IBS can be done in two systems, either an open IBS or closed IBS. Open IBS system allows the combination of prefabricated building components from various factories and the components are compatible with each other to be used in a building project. A successful implementation of this system requires a modular coordination. Closed IBS is where all building components have only specific designs for specific project. This system does not allow interchangeability of components from different factories.

Modular Coordination (MC) is a standard of measurement for IBS elements to coordinate the dimension and space, in accordance to MS 1064. It is where a building and its components are being dimensioned and positioned in a basic unit or module known as 1 M which is equivalent to 100 mm.

2

1.2

Type of IBS in Malaysia

Precast Concrete System

Prefabricated Timber Framing System

Blockwork System

Formwork System

Steel Framing System

Precast concrete system is the most widely used IBS system in Malaysia.

It consists of precast concrete columns, beams, slabs, walls, staircases and building components such as toilet pods, balconies, lift chambers, refuse chamber.

Prefabricated timber framing system involves the timber frames, roof trusses, beams and columns. It is commonly used in simple dwelling units with high aesthetic value such as chalets and resorts.

The blockwork system is the alternative to the traditional brick laying technique. This system consists of interlocking masonry unit and lightweight concrete blocks, which may include hollow cores to make them lighter while improving insulation properties.

This system is the least prefabricated as site casting is normally involved. Formwork system consists of tunnel forms, tilt up systems, beams and columns moulding forms and permanent steelwork form.

Steel framing system consists of steel beams and columns, roof trusses and portal framing system.

It is usually used in high-rise buildings and skyscrapers due to its fast rapid erection site. This system also has the capacity to transfer heavy loads on a larger span.

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1.3

Advantages & Disadvantages of IBS

Advantages

Disadvantages

Reduction of unskilled workers & construction time leading to considerable cost saving

High initial cost

Elimination of conventional timber props and decrease of timber supports thus less wastage, promoting Increased environmental and construction site cleanliness

Can only be used for large scale projects

Construction process is not affected by adverse weather condition

Requires high skilled labours

High quality of components ensure better quality control

Low supply

Safe and more organized construction site

Rigidity of building

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1.4

Standard IBS Workflow

Ideation & Design Manufacturing of Components Delivery to Site Assembly & Erection Completion

01 Design coordinating with IBS system based on specifications stated in MS 1064. All consultants meet up and decide on the design specification based on the IBS system coordinates.

02 After submission & approval, building components are manufactured in modules according to standard dimensions and quality.

03 Manufactured components are delivered to site upon inspection.

04 Components are assembled and installed based on the technical drawings with the aid from machineries

05 After final finishes, receive the Certificate of Completion and Compliance & ready for occupancy!

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1.5

Precast Concrete System 1.5.1 Post & Beam System

1.5.1 Shear Wall System

Structural framing by precast concrete columns and beams, with slabs and other 3D components (balcony, toilet, stairs) that are fabricated or manufactured off-site using machine and formwork.

Structural framework of the building is composed of precast slab and load bearing wall. The load bearing walls and slabs are manufactured off-site and transferred at site to be erected.

The advantage of the system is high degree of flexibility as there can be larger clear distance between columns, as a result longer span give bigger open space and greater freedom of areas.

The system is preferred in simple and uncomplicated with a lesser degree of flexibility whereas the removal of load bearing wall are restricted during the service life. With careful design and good coordination between erectors and designers, the erection process can be very fast with the number of wet trade in-site can be reduced significantly.

Roof/floor span systems: 1.

Structural concrete T-sections 2.

Structural double T sections 3.

Hollow-core concrete slab

Curtain wall systems: 6.

Precast concrete panels 7.

Metal, glass or stone panels

Wall systems Structural system 4.

Load-bearing frame components 8.

Precast columns and beams (cross) 5.

Multi storey load-bearing panels

Roof/floor span systems: 1.

Heavy timber rafter roof 2.

Concrete joist and slab 3.

Concrete flat slab

Wall system: 4.

Interior and exterior concrete load bearing wall 5.

Large window penetrations of school and hospital buildings

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1.6

Case studies 1.6.1 Hospital Kuala Lumpur

1.6.2 Residential Seri Jati Apartment

IBS System : ● Cast in-situ columns using aluminium formwork with precast beams as structural framing ● Combination of cast in-situ slab (at wet areas) and precast hollow core slab ● Aluminium formwork for structural walls ● Blockwork for external and internal walls ● Precast staircase

IBS System : ● Precast structural frames with in-situ concrete floor using reusable formwork system ● Precast load bearing & non-load bearing walls with vertical & horizontal repetition ● Typical cast in-situ floor slabs ● Precast staircases & landing slabs ● Prefabricated Steel Roof Trusses

Total : 9 storeys IBS Score : 70.2 /100

Total : 10 storeys IBS Score : 81.9 /100

A day care specialist centre which comes with operation theatres, built in 3 floors of internal car parks with separate M&E blocks make up floor area of 600,000 sqm of Hospital Kuala Lumpur.

For a 948 units, 6 blocks, 10 storey apartment in a single phase development, this project has high degree of repetitions for both horizontal and vertical plain. High economy of scale is shown with >900 units apartment with a single unit layout. Construction logistic is fully considered at planning stage, which includes wall layout, work sequencing, crane’s capacity and movement.

To resolve proximity of existing buildings and roads, logistic planning by allowing an internal crane passage serve to maximise cranage radius. Each bay is constructed up to roof level before the crane retreat to next bay and repeat the sequence.

However, brickwork and plastering in stand alone amenities building, box-out for M&E risers and kitchen/yard walls does not show compliance in modular coordination for structural elements and architectural design input.

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1.6

Case studies 1.6.3 Sekolah Kebangsaan Brickfields

1.6.4 Idaman Residensi, Sepang

IBS System : ● Precast concrete columns and beams with hollow core slabs, precast staircase & prefabricated wall panels

IBS System (Work in progress ): ● Digital Industrialised Building System (IBS) project ● Fully automated precast production system

Completion time : 7 half months

Expected completion time : 04 / 01 / 2021 Total : Two blocks of 14- and 15-storey towers IBS Score : 75 /100

The compact design houses two schools in a total site area of 2

4,488 m . The project has 75% of its building components prefabricated, such as precast columns, beams, staircases, and hollow core floor slabs. Due to the use of repetitive elements and rapid construction of precast components, the construction period the lasted about 7 ½ months, with its completion date by 17th September, 2003.

For the Idaman Residensi project, Gamuda IBS will achieve QLASSIC of 75 points, surpassing the industry achievement for affordable homes of 65 points.

Idaman Residensi comprises two blocks of 14- and 15-storey towers, with 864 apartment units measuring 1,000 sq ft on 5.8ha site. The development offers various facilities such as three convenience shops, a four-storey parking complex, motorcycle parking, four units for disabled, prayer room, kindergarten, management office and multi-purpose hall.

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2.1 2.2

Proposed IBS system Features & fabrication process of IBS components 2.2.1 Precast Column 2.2.2 Precast Beam 2.2.3 Precast Wall 2.2.4 Precast Floor Slab 2.2.5 Precast Staircase 2.2.6 Toilet Pod 2.2.7 Precast Balcony 2.2.8 Prefabricated Steel Roof Truss

2.3

Sequence of construction

02 concept & framework

2.1

Proposed IBS System

PRECAST COMPONENTS Column Beam Hollow core slab Wall Staircase

CAST IN-SITU COMPONENTS Pad footing foundation Ground beam Ground slab

PREFABRICATED COMPONENTS Steel roof truss Window & Door Railings

ADDITIONAL COMPONENTS Toilet pods Balcony

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2.2

Features & fabrication process of IBS components 2.2.1 Precast Column

2.2.2 Precast Beam

Figure 2.1 Precast column

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete IBS Factor : 1.0 (Full IBS Factor)

Figure 2.2 Precast Beam

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete IBS Factor : 1.0 (Full IBS Factor)

Precast concrete column is a load bearing element to support beams and slabs as a structural system. These precast concrete columns are reinforced with four steel rebar for additional tensile and compressive strength to resist bending forces. Corbel are used to distribute the load and to support the weight of the beams. Together, the columns and beams, form structural framing of the building.

Where single storey columns are being used, continuous beams are cast to reduce the bending moment of the beam and, therefore, its depth. Continuous beams can also extend beyond the column support and provide bearing for smaller drop in beams between them.

ADVANTAGES

Economical Reduced cost on installation time, labour work and on-site material wastage

Reduced Cost Wastage of building materials and the need of labour can be avoided. Due to reduced construction period, overhead cost for efficient installation is lower compared to conventional method.

Durability Resistance towards fire and high temperature Design Options Flexible sizing and configuration to be customized to fit client’s specifications

ADVANTAGES

Aesthetic Structurally efficient beams can be left exposed with natural finishes

SUITABILITY Concrete Beam vs. Steel Beam Concrete beam is stronger in tension compared to steel beam. Concrete beam requires a lesser structural requirement on the connection and makes it easier during erection whereas steel beams may have rolling behaviour

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2.2

Features & fabrication process of IBS components

Figure 2.3 Fabrication of precast columns and beam

FABRICATION PROCESS OF PRECAST COLUMNS & BEAMS 1.

The mould of the columns and beams are assembled and the dimensions of the mould are within the specified tolerances. The level and flatness of the base mould is checked before assembling the mould for panel casting

2.

The mould is cleared and mould release agent is poured evenly over the mould surfaces. Rebars and prestressing strands are fixed into the mould and the lengths and dimensions are checked in accordance to the drawings.

3.

Sufficient number of spacers with the correct size should be properly placed and secured before casting.

4.

Concrete slump test is conducted to ensure the strength and quality of the concrete mix is up to required safety standards before pouring the concrete over the mould.

5.

Suitable curing time is observed so that the desired and same environment is achieved for all precast components.

6.

Cube tests are conducted to verify the concrete strength before demoulding and then all bolts and pins from the mould is loosened and removed before lifting and transporting to site.

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2.2

Features & fabrication process of IBS components FABRICATION PROCESS OF PRECAST WALL

2.2.3 Precast Wall

1.

Checking of the level and the flatness of the base is done before assembling the mould for panel casting.

The dimension of mould is checked to ensure that it is within the specific tolerance.

1.

The mould is then cleaned to prevent debris and old mortars using removers or scaling bars. The rebar size, spacing and length is checked according to the drawing.

2.

Fixing of prestressing strands such as corrugated sleeve pipes, recesses and lifting hooks must be correctly positioned and secured.

3.

Vibration and compaction will be carried out during the final inspection before casting is taken place.

Spreading and levelling of concrete is done at this stage.

4.

Power Trowel or float is used for a smooth surface finish during concretion.

5.

Observe the adequate curing time and desired environment.

6.

Bolts and pins are loosen and removed before lifting.

Strands are also cut before lifting for prestressed elements.

7.

Final inspection where the condition of the final product and the dimensions are carefully checked before going to storage.

Figure 2.4 Precast Wall

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete IBS Factor : 1.0 (Full IBS Factor) Many precast concrete walls are cast in a flat position at the building site. but they are still classified as precast, not sitecast.

When the concrete is strong enough, the wall panels are lifted and placed in the desired positions for the building. This method is commonly known as tilt-up construction. Today such walls are lifted and placed with cranes, so that casting can make repeated use of single forms. Some wall units are cast in factories, where the form, quality of materials, and finishing can be more controlled.

ADVANTAGES Easy Installation Embedded connections hardware on panels allows it to be erected onto a steel frame quickly with a limited installation crew, reducing the overall project timeline saving constriction cost Strength Exterior cladding panels can easily be designed to handle structural building loads, thereby reducing the need for other structural components Durability Does not deteriorate, or loses strength over time Quality Control Factory production to ensure product is consistent and meets all quality standards Aesthetic Precast panels can be produced in virtually any colour, textures and desired finishes

Figure 2.5 shows the preparation of rebars based on size and length provided in the working drawing

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2.2

Features & fabrication process of IBS components 2.2.4 Precast Hollow Core Slab

FABRICATION PROCESS OF PRECAST HOLLOW CORE SLAB 1.

Prestressed hollow core slabs are produced on casting beds. Before casting, the beds are cleaned and oiled.

2.

All of the strands for one bed are tensioned simultaneously or individually tensioned.

3.

Concrete is transported from the batching and mixing plant. The concrete is then poured, forming slab around the reinforcement.

4.

Openings can be easily be made after the casting process while the concrete is still green. Openings can be made by machine or hand.

5.

After curing, tensions on the strand is released and the slab is cut accordingly,

6.

After the cutting, slabs are lifted from the casting bed.

The slabs are then transferred to an automatic drilling device that drills drainage holes in both ends of the slab.

7.

Slabs undergo quality control, after which the voids are fitted with sealing plugs and is then brought to storage.

8.

The slabs are then delivered to site and is ready for installation.

Figure 2.6 Hollow Core Slab

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete IBS Factor : 1.0 (Full IBS Factor) Hollow core slabs used are pre-stressed concrete units with tubular voids extending the full length of the slab, creating an efficient lightweight unit This slab is a precast slab of prestressed concrete typically used in the construction of floors in high rise apartment buildings and commercial buildings. The name is derived from the void and cores which run through the unit, where the cores can function as service ducts. This significantly reduce the self-weight of the slabs by about 35 percent, maximising the efficiency of the structure. The hollow core also allows the exploitation of strength and durability of precast concrete by placing reinforcement bars and concrete into it, while reducing the weight which is the main drawback.

ADVANTAGES

SUITABILITY

Integration Long horizontal slabs that can be used as service duct to run mechanical and electrical equipment

Hollow Core Slab vs. Solid Slab

Lightweight The primary purpose of the cores/voids running through the slabs continuously is to decrease the weight and materials within the floor whilst maintaining the maximal strength.

Easy Installation No need for any complicated formwork, or even temporary propping, which gives free space with easy accessibility within the construction site.

High Compressive Strength Can handle heavy load requirements in structures without increasing the deck thickness or adding multitudes of beams and columns

The application of hollow core slab has tubular voids running the full length of the slab, making the slab much lighter than a massive solid concrete floor slab of equal thickness or strength, reducing the structural weight of the apartment block. The hollow cores in the slab also allows the insertion of reinforcement bars that connects to the concrete wall, strengthening the structural integrity of both components.

Figure 2.7 shows the slabs undergoing quality control before it is delivered to site

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2.2

Features & fabrication process of IBS components FABRICATION PROCESS OF PRECAST STAIRCASE

2.2.5 Precast Staircase

1.

Assembly of staircase mould made from timber formwork

2.

The mould is then cleaned and is prepared for the next stage of fabrication.

3.

Reinforcement bars are then fixed and installed.

4.

Pouring and vibration of concrete will be carried out during the final inspection before casting is taken place. Spreading and levelling of concrete is done at this stage.

5.

Concrete is then cured to form solid stair slab. The adequate curing time and desired environment. Is ensured.

6.

The staircase is then lifted and is ready to be installed on site.

Figure 2.8 Precast Staircase

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete Precast concrete staircase slabs are usually designed to span longitudinally into the landings at the right angle to the stair flight or span between supporting beams. The main components of precast concrete staircase, which are the staircase flights, landings and steps are commonly manufactured at the factory together with the connections being fabricated along with the stairs, for easier assembly on site. To strengthen the structure, reinforcement bars are added during the fabrication process.

The installation of precast concrete staircases is usually taken place after the man substructure, with ...

ADVANTAGES

SUITABILITY

Cost Saving Saving cost by reducing construction time up to weeks due to modular size of staircase

Concrete vs Timber/Steel Staircases

Organised Construction Site Environment Stairway enclosing shaft can be utilized for hoisting or lifting of materials and equipments during the major construction period Quality Control Consistency quality through stringent quality control in manufacturing process

The materiality of concrete makes it more durable compared to other materials as it is reinforced with rebars, strengthening the structural integrity of the staircase. Precast concrete is chosen instead of in-situ as it saves construction time and also save space on site as the formwork storage space and fabrication space is not required.

Quality Finish Allows the finishings of prefabricated concrete staircase elements with other materials such as timber and stone Figure 2.9 shows the fabrication process of precast staircase from the factory and during installation.

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2.2

Features & fabrication process of IBS components 2.2.6 Toilet Pod

FABRICATION PROCESS OF TOILET POD 1.

Necessary arrangements are made before the toilet block, floor, wall and roof is assembled.The centre line of different walls and door of toilet in reference with the pan before positioning the 1st panel for installation.

2.

Prior to surface grouting the joints the surface receiving, the grout is mixed and applied properly.

Apply surface grout on the bottom and on one face of panel to be erected vertically.

3.

Similarly, all the remaining panels are erected to make the walls of the toilet pod. Cavity anchor “L” can be used for further locking and holding at the corners of the wall at top and bottom.

4.

Cavity Anchor in “U” shape is used for further locking and holding of panels. Services duct such as electrical wiring and plumbing can be concealed within the core of the wall panel after installation.

5.

Top roof panels is placed on the wall by interlocking them. Fiberglass is placed on the jointing area while cementation process is done to seal any gap if necessary.

6.

Cement mortar is filled in the gaps at top and bottom of each panel. The walls are thoroughly checked before it is plastered and level it with skim coat before it is ready to be transported to site.

Figure 2.10 Toilet pods

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete

Toilet pods are fully functional bathrooms. The key difference being that they are designed and built offsite, rather than on a traditional building site as part of a construction project. Useful for commercial applications in particular, toilet pods are built in an offsite factory as a completed unit, and are then fully tested and fitted with all of the required fixtures and fittings such as taps, rails, mirrors, and appliances. The pods are then simply delivered to the site for installation, where they are connected to the plumbing and electrical services.

ADVANTAGES

SUITABILITY

Streamlined Construction Since the pods are all the same, construction processes are dramatically streamlined, resulting in many efficiencies and less waste. This has an impact on the ultimate cost of a project, the time that it takes to complete, and everything else that plugs into these factor

Bathroom Pod vs. Site Built Bathroom

Cost Saving Lowers construction cost by reducing construction time, improving quality, and eliminating bathroom defects.

Bathroom pods have a higher level of quality that can be achieved compared to site built construction. The blocking is far superior to site built and prevent tiles from coming loose over time, making it durable and easier for maintenance and renovation.

.

Quality Control When constructing the bathroom pods in an offsite factory, there is greater control over the construction process. The production environment is clean and organised, which results in a better quality product with less defects Less Waste Since the pods are delivered to a site after they have been completed, the waste that needs to be removed from a building site is dramatically reduced.

Figure 2.11 shows the fabricated toilet pod which is ready to be installed

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2.2

Features & fabrication process of IBS components 2.2.7 Precast Balcony

FABRICATION PROCESS OF PRECAST BALCONY

Figure 2.12 Precast Balcony

Construction Method : IBS - Precast Concrete System Construction Material : Reinforced Concrete

1.

Prestressed balconies are produced on casting beds.

Before casting, the beds are cleaned and oiled.

2.

All of the strands for one bed are tensioned simultaneously or individually tensioned.

3.

Concrete is transported from the batching and mixing plant. The concrete is then poured, forming slab around the reinforcement..

4.

After curing, tensions on the strand is released and the balconies are cut according to size and dimension of the working drawing.

5.

The balconies then undergo quality control, after which the voids are fitted with sealing plugs and is then brought to storage.

6.

The slabs are then delivered to site and is ready for installation

Precast balconies can be either prestressed or conventionally reinforced. They are made with a standard (non-slip) light broom finish. They can be manufactured to any custom shape and configuration, including radiuses and upstands. Balconies are generally designed with a sloped top surface and a drip edge on the underside for proper drainage and water run-off.

ADVANTAGES

SUITABILITY

Cost Saving Lowers construction cost by reducing construction time, improving quality, and eliminating bathroom defects.

Precast Balcony vs On-site Casted Balcony

High Quality Finish Can be precisely made to the desired specifications, and provide a high quality finish. This contrasts to on site casting which can be inaccurate and where finishes are prone to being affected by adverse weather conditions, sometimes requiring additional remedial work.

Design Flexibility Rainwater outlets can be incorporated into the concrete balcony design.Cold bridging can be solved by implementing a thermal break system as part of the concrete balcony construction Durable Resistant to nature, from termites or hurricanes to high winds and seismic events.

Manufacture is not affected by adverse weather conditions and rain water outlets can be incorporated into the finished balcony. The issue of cold bridging can be overcome by incorporating a thermal break such as the Schock isokorb system as part of the balcony

Figure 2.13 shows the fabricated balcony which is ready to be transferred and installed at site

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2.2

Features & fabrication process of IBS components 2.2.8 Prefabricated Steel Roof Truss FABRICATION PROCESS OF PREFABRICATED STEEL ROOF TRUSS

Figure 2.14 Prefabricated steel roof truss

1.

Feeding of metal strips by automated decoiler into roilformer

2.

Bending of metal strips by rollformer into C-channel steel profile

3.

Cutting, punching and measuring C-channel steel profile to exact dimensions

4.

Assembly of individual parts to form a roof truss

5.

Connecting all parts manually using bolts and screw guns

Construction Method : IBS - Prefabricated Steel Framing System Construction Material : Steel (Galvanised C channel roof truss) IBS Factor : 1.0 (Full IBS Factor) Prefabricated steel roof truss offers a high strength, lightweight roof system that can be installed quickly, upon arrival on site from manufacturer. In residential construction, timber truss still dominates the industry, however light gauge steel roof systems are gaining ground in markets where additional strength is needed, or where greater free spans are required.

ADVANTAGES

SUITABILITY

High strength to weight ratio Lighter-weight advantage reduces materials shipping costs, and also simplify the design of a building's foundation and other structural support systems

C Channel Profile vs. RHS Profile

Reduces construction & labour cost Highly quality-controlled fabrication process thus the pre-cut, ready to assemble parts eliminate the need for measuring and cutting on site.

Increase construction speed Element of human error is eliminated, reducing the amount of time spent assembling something only to find out it needs to be re-measured, cut and installed again.

Allows roof designs with superior spanning capacities Reduced roof volume & depth, and hence increased span.

As shallow foundation is used, the usage of lightweight C channel steel profiles can reduce structural loads compared to rectangular hollow section (RHS) steel profiles.

Steel Trusses vs. Timber Trusses Although more expensive than timber roof trusses, steel roof trusses last longer and require less maintenance in terms of termite resistance Figure 2.15 shows the fabrication process and materials needed to produce fabricated steel roof trusses.

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2.3

Sequence of construction

01

04

Foundation

Slabs

Foundation is cast on site on the excavated terrain.

Cast in-situ slab is then cast on top of the ground beam.

02

05

Ground Beams

Beams

Cast in- situ ground beams are placed on top of the concrete footings.

Precast beams are then placed above the columns.

03

06

Columns

Walls and Toilet Pod

Precast columns with corbel are then erected.

Precast walls with doors and windows are then installed followed by the toilet pods.

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2.3

Sequence of construction

07

10

Staircase

Balcony

Precast staircase is installed using a crane to connect the ground floor landing with the first floor landing.

Precast balconies are then installed before the roof is installed.

08

11

First Floor Slab

Roof Truss

Hollow core slab is then installed on the first floor beams.

Prefabricated steel roof trusses and rafters are then installed on the third floor beams.

09

12

Second and Third Floor

Finishing Touches Railings on the staircases

Steps 3 - 7 is then repeated for the second and third floor.

and balconies are then installed.

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3.1 3.2 3.3

Architectural Drawings Structural Drawings Axonometric

03 technical drawings

3.1

Architectural Drawings

COMMON FLOOR PLAN SCALE 1:100

22

3.1

Architectural Drawings

ROOF PLAN SCALE 1:100

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3.1

Architectural Drawings

SECTION X-X’ SCALE 1:100

24

3.1

Architectural Drawings

SECTION Y-Y’ SCALE 1:100

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3.1

Architectural Drawings

Repetition of floor to floor height (3300mm)

FRONT ELEVATION SCALE 1:100

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3.1

Architectural Drawings

BACK ELEVATION SCALE 1:100

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3.1

Architectural Drawings

LEFT ELEVATION

RIGHT ELEVATION

SCALE 1:100

SCALE 1:100

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3.2

Structural Drawings

GROUND FLOOR STRUCTURAL PLAN SCALE 1:100

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3.2

Structural Drawings

C3

B3 C1

B3 C1

Vertical repetition of structural floor layout Horizontal repetition of structural floor layout

B5

C1

B3 C4

B3 C4

B4

C2

C2

B2

B3

B3 C1

C1

C5

C5

B2

C4

B2

C4

C3

B3 B1

B3

B4

B4

B1

B3

B3

B3

C1

C1

B3 B1

B4

C1

B5

B6 C3

C1

C2

C2

B2

C1

B1

C3

B7

COMMON STRUCTURAL PLAN SCALE 1:100

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3.2

Structural Drawings

S7

S9

S7

S8

S8

S6

S3 S3 S3 S3 S3 S3 S3 S3 S3 S3

S3 S3 S3 S3 S3 S3 S3 S3 S3 S3

S9 S3 S3 S3 S3

S6

S3 S3 S3 S3

S2 S2 S2 S2 S2 S2 S2 S2

S2 S2 S2 S2 S2 S2 S2 S2 S5 S5

S5 S5 S1 S1 S1 S1 S1 S1 S1 S1

S1 S1 S1 S1 S1 S1 S1 S1 S4

S4

COMMON STRUCTURAL PLAN SHOWING SLAB PLACEMENT SCALE 1:100

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3.2

Structural Drawings

ROOF STRUCTURAL PLAN SCALE 1:100

32

3.2 Exploded Axonometric

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4.1 4.2 4.3 4.4 4.5 4.6 4.7

Precast Columns Precast Beams Precast Wall Precast Floor Slab Doors & Windows Precast Staircase, Balcony & Prefabricated Roof Truss Toilet Pod

04 schedule of IBS components

4.1

Precast columns

All columns (100%) follows prefered size suggested by MS 1064 Part 10:2001 showing utilisation of Standardised Components

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4.2

Precast beams

36

4.2

Precast beams

All beams except B5 (108/114 x 100 = 94.7%) follows prefered size suggested by MS 1064 Part 10:2001 showing utilisation of Standardised Components. Compromise is done at B5 for attachment of balcony.

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4.3

Precast wall

38

4.3

Precast wall

39

4.3

Precast wall

All walls are made up of 900mm x 3000mm precast concrete panels, following prefered size suggested by MS 1064 Part 10:2001 showing utilisation of Standardised Components.

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4.4

Precast slabs

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4.4

Precast slabs

All slabs except S6 & S7 (210/222 x 100 = 94.6%) follows prefered size suggested by MS 1064 Part 10:2001.

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4.5

Doors & Windows

All doors except D2 (24/36 x 100 = 66.7%) follows prefered size suggested by MS 1064 Part 4:2001.

All windows except WD1 (30/36 x 100 = 83.3%) follows prefered size suggested by MS 1064 Part 5:2001.

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4.6

Precast Staircase, Balcony & Prefabricated Roof Truss

100% usage of prefab staircase

44

4.7

Toilet Pod

100% usage of prefab bathroom units

45

5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9

Foundation Precast Columns Precast Beams Wall Precast Floor Slab Precast Staircase Toilet Pod Balcony Prefabricated Roof Truss

05 construction details & process

5.1

Foundation SYSTEM : Cast In-situ Pad Foundation Pad foundation, ground beam and ground slab are cast in-situ using prefabricated reinforcement cages and self-compacting concrete for a higher IBS score.

Precast concrete column

Column shoes ďŹ lled with cement grout to prevent corrosion of anchor bolt

Column shoes

CONNECTION DETAILS: Foundation to column : Bolted The anchor bolts transfer tension, compression and shear force to the pad footings.

Anchor bolts

200 x 200mm Column stump

Anchor bolt 150mm thick ground slab cast in-situ 200 x 300mm ground beam cast in-situ

2000 x 2000mm Concrete footing

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5.2

Precast columns SYSTEM : Precast concrete column

INSTALLATION ON SITE :

Our proposed 3-storey apartment incorporate columns of 200MM X 200MM and 200mm x 400mm. The size of columns follows MS 1064 preferred size for reinforced concrete components to achieve higher IBS score. The column is also a part of the fin facade design.

MOMENT RESISTING CONNECTION PROCESS

1.

A moment-resisting connection is made quickly by lowering the column in place and tightening the nuts to specified torque with readily available hand tools. The installation process takes on average 20 minutes per column and requires only a crane operator and two people on the ground.

2.

The connection is finalized by grouting the anchor bolt recesses and joint underneath the column with non-shrink grout.

GROUTING THE ANCHOR BOLT RECESSES AND JOINT

INSTALLATION IN PROGRESS

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5.2

Precast column Column to Column Connection

Grout Metal bearing plate

Anchor bolt

CONNECTION DETAILS: Bolted & Grouted 1.

Column to column splices are joined using bolted mechanical connections in the separate precast components. Metal bearing plates and embedded anchor bolts are cast into the ends of the columns.

2.

After the columns are assembled properly and mechanically joined, the connection is grouted to provide full bearing between the elements and to protect the metal components from ďŹ re and corrosion.

Precast concrete reinforced with rebar

Metal shim

Metal bearing plate and embedded anchor bolts are cast on the ends of columns

The anchor bolts are tightened with bearing plate with nuts by hammering

The open corners are the ďŹ lled with high strength cement grout

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5.3

Precast beams SYSTEM : Precast concrete beams Our proposed 3-storey apartment incorporate rectangular beams of 200mm x 300mm and 400mm x 300mm. All beams (200m x 300m) except six (400mm x 300mm) follows MS 1064 preferred size for reinforced concrete components.

SET REFERENCE LINE

INSTALLATION ON SITE : 1.

Framing plans show a plan view of the the beams with their markings. These beams have erection marks stamped on them to show their placement in the plan. Prestressed concrete beams are erected according to framing plans.

2.

Set up temporary props to support the precast beams.

3.

Prestressed beams are lifted into place and lowered onto their bearings. Centerline of the bearing of the beam which coincides with the centerline of bearing for the bearing on the pier is veriďŹ ed.

SET UP TEMPORARY PROPS

LIFT WITH CRANES AND WIRE ROPES

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5.3

Precast beams Beam to Column Connection

Welded plate

Bearing plate

CONNECTION DETAILS: Welded & Grouted

Corbel

1.

Beams are set on bearing pads on the column corbels.

2.

Steel angles are welded to the metal plates cast into the beams and columns.

3.

The joint is grouted solid to protect the metal components from ďŹ re and corrosion.

Column bars Column ties Weld plate cast into beam Stirrup Bearing pads on corbels

200mm x 400 mm precast concrete column

Weld plates cast onto column

Prestressed tendons

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5.4

Precast Wall SYSTEM : Precast concrete walls Our proposed 3-storey apartment incorporate 900mm x 300mm precast wall panels. The size of precast wall panels follows MS 1064 preferred size for reinforced concrete components to achieve higher IBS score.

LIFTING AND INSTALLATION

INSTALLATION ON SITE : 1.

The reference line and offset line is set to determine the position of the precast wall that is to be installed.

2.

Lift the panel to its designated location with the use of wire ropes.

3.

Prepare and apply non- shrink mortar to seal the gap along the bottom edge of the inner side of the panel.

4.

The forms of the casting of vertical joints is set up and is followed by the casting of concrete. Removal of forms is done after the concrete has achieved the suďŹƒcient amount of strength.

GROUTING WORK

JOINT CASTING AND SEALING

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Precast Wall Slab to Wall Connection

Precast hollow core Grout

Horizontal reinforcement

CONNECTION DETAILS: Edge Support Precast Precast hollow core concrete wall

Vertical Reinforcement

80 at support

5.4

30 x 3mm Neoprene Bearing Strip Not less than 50mm Bearing

2xY12 typically

1.

Precast walls are casted with connecting rebars which are left protruding, which will eventually be inserted into the holes casted into the beams.

2. The connection is grouted in order to secure its strength and stability.

200mm thick precast concrete wall

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Precast Wall Slab to Wall Connection

Precast Hollow Core Slab

Horizontal Reinforcement

CONNECTION DETAILS: Internal Support 1.

Precast Concrete Wall Vertical Reinforcement

Precast walls are casted with connecting rebars which are left protruding, which will eventually be inserted into the holes casted into the beams.

2. The connection is grouted in order to secure its strength and stability.

Reinforcement in accordance with project requirements

80 at support

5.4

No chamfers on panel 30 x 3mm Neoprene Bearing Strip

Not less than 50mm Bearing

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5.5

Precast Hollow Core Slab SYSTEM : Precast hollow core concrete slab Our proposed 3-storey apartment incorporate precast hollow core slabs of various sizes (refer to schedules).

Most of the slab size follows MS 1064 preferred size for reinforced concrete components to achieve higher IBS score.

INSTALLATION ON SITE : 1.

Unloading and hoisting of transported precast hollow core slabs is conducted using a hoisting transverse.

2.

Hollow core slabs are then installed on a levelling neoprene strip, fastened to the bearing structure.

3.

Different curvatures of adjacent slabs may occur due to influences such as improper storage of slabs, transportation and different length of slabs. Clamping device will be used to equalize the curvature occured on the slabs

4.

The quantity of slabs needed, the location on the floor, and concreting peculiarities is to be indicated.

5.

The installation joints that are between the slabs and the end of the slabs should be filled up with fine aggregate concrete to make sure that it is perfectly covered.

HOISTING

EQUALIZING THE CURVATURE

FILLED UP WITH FINE AGGREGATE CONCRETE

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5.5

Precast Hollow Core Slab Slab to Beam Connection Gap for Screed/ Structural Topping

Precast Concrete Hollow Core Slab

Precast Concrete Beam

Reinforcement Bars

Stirrups

CONNECTION DETAILS: Edge Support Reinforcement bars are bent into hollow core slab to secure the placement of the slabs.

20Ø Barlink Grouted in 50Ø PVC Ducts

75 x 75 x 5 Structural Washer & Reid Bar Structural Locknut

30 x 3mm Neoprene Bearing Strip

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5.5

Precast Hollow Core Slab Slab to Beam Connection Gap for Screed/ Structural Topping

Precast Concrete Hollow Core Slab

Reinforcement Bars

Precast Concrete Beam

CONNECTION DETAILS: Internal Support Reinforcement bars are connected vertically and horizontally into the hollow core slab.

Locally Blockout End of Beam To Suit Nuts & Washer

Roughen Side of Beam 60 Average Structural Screed

30 x 3mm Neoprene Bearing Strip

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5.6

Precast Staircase SYSTEM : Precast concrete staircase Our proposed 3-storey apartment incorporate precast concrete staircase as one of the productivity enhancing solutions for higher IBS score.

INSTALLATION ON SITE : 1.

Prefabricated concrete ight of stairs are served by a crane sling where it will be transported to the placement of the stairs.

2.

Dowels are secured to the foundation to ďŹ x the position of the stairs.

3.

The precast stairs are then set on the brackets and pads using a boom tuck. Solid steel shims are used to make small adjustments if necessary.

4.

TRANSPORTED BY A CRANE SLING

The railings are installed in the precast unit and held in place with anchoring element.

BRACKETS AND PADS ARE SET

RAILINGS ARE INSTALLED

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5.6

Precast Staircase

CONNECTION DETAILS: Landing to Column Connection : Steel angle support bolted to the precast wall to strengthen the structure.

Precast Landing Slab

Steel angle support bolted to the precast wall Precast concrete column

CONNECTION DETAILS: Stairs to Landing Connection : The landing slab sits on a rolled steel angle (RSA) that is bolted to the wall. A structural shim packer is placed between the landing slab and RSA, it serves to level the landing slab before commitment.

CONNECTION DETAILS: Stairs to Ground Floor Slab Connection : The stairs sits on a structural shim packer which sits on the ledge casted into the oor slab. A hole is then bored through the step of the stairs and the shim packer and stops when it reaches into the slab. A metal dowel piece is then inserted into the hole and is then sealed by grout.

75mm thick concrete screed

Precast landing slab

Bars from precast stairs Precast stairs riser

Precast staircase riser

Holes from precast staircase

Ground oor slab

Dowels drilled onto foundation

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5.7

Toilet Pod SYSTEM : Prefabricated bathroom units Our proposed 3-storey apartment incorporate toilet pod as one of the productivity enhancing solutions for higher IBS score.

HOISTING

INSTALLATION ON SITE : 1.

The condition of the bathroom pods are inspected on site to verify its structural integrity.

2.

The bathroom pods are hoisted to the building using cranes and wire ropes.

3.

Workers hoist the toilet pod to its final position.

4.

The steel frames of the toilet pod are connected to the floor slabs using steel brackets and bolts.

5.

The exterior of the pod is plastered to give it a finish that blends in with the rest of the interior.

CONNECTING STEEL FRAMES

PLASTERED FINISH

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5.9

Prefabricated Roof Truss Roof Truss to Beam Connection SYSTEM : Prefabricated steel roof truss system CONNECTION DETAILS: Anchor bolted & Welded Prefabricated roof truss are secured onto the beam through anchor bolts and welded metal plates connections

INSTALLATION ON SITE : 1.

Trusses are lifted by a crane and is aligned into position and which is bolted into place.

2.

Prefabricated roof trusses are secured onto the building through anchor bolts and welded.

3.

The C-channel purlins are then welded onto the rafters.

C-channel steel purlin

Purlins welded into prefabricated steel roof truss

Steel roof truss

Prefabricated steel roof truss

Anchor bolt joint to precast concrete beam 200mm x 300mm precast concrete roof beam

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6.1 6.2 6.3

Part 1: Structural System Part 2: Wall System Part 3: Other SimpliďŹ ed Construction Solution

06 calculation of IBS score

6.1

Part 1: Structural System

Elements

Area (m2)

IBS Factor

Coverage

IBS Score

Ground floor Precast columns and in situ beams using reusable formwork + In Situ Concrete Using Reusable Formwork

231.24 m2

0.5

(231.24/991.052) = 0.233

0.233 x 0.6 x 50 = 6.99

*prefabricated reinforcement cages are used in all cast in situ structures *self-compacting concrete is used in all cast in situ structures.

Total

+0.05 +0.05 0.6

First Floor Precast columns and beams + Precast Hollow Core Slabs

231.24 m2

1.0

(231.24/991.052) = 0.233

0.233 x 1 x 50 = 11.65

Second Floor Precast columns and beams + Precast Hollow Core Slabs

231.24 m2

1.0

(231.24/991.052) = 0.233

0.233 x 1 x 50 = 11.65

Roof Prefabricated Steel Roof Truss

297.332 m2

1.0

(297.332/991.052) = 0.3

0.3 x 1 x 50 = 15

991.052 m2

-

0.999 (=1.00)

45.29

TOTAL (PART 1)

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6.2

Part 2: Wall System

Elements

Length (m)

IBS Factor

Coverage

IBS Score

External wall Precast concrete wall panels

71.6 m

1.0

(71.6/114.4) = 0.626

0.626 x 1.0 x 20 = 12.52

Interior wall Precast concrete wall panels

42.8 m

1.0

(42.8/114.4) = 0.374

0.374 x 1.0 x 20 = 7.48

114.4 m

-

1.00

TOTAL (PART 2)

20

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6.3

Part 3: Other SimpliďŹ ed Construction Solution

Elements

Coverage

IBS Score

Utilisation of Standardised Components Based on MS 1064 Columns (follow MS 1064 Part 10:2001) Beams (follow MS 1064 Part 10:2001) Walls (follow MS 1064 Part 10:2001) Slabs (follow MS 1064 Part 10:2001) Doors (follow MS 1064 Part 4:2001) Windows (follow MS 1064 Part 5:2001)

100% 94.7% 100% 94.6% 66.7% 83.3%

4 4 4 4 2 4

Repetition of Structural Layouts Repetition of floor to floor height Vertical repetition of structural floor layout Horizontal repetition of structural floor layout

100% 100% 100%

2 2 2

Other Productivity Enhancing Solutions Usage of prefab bathroom units (PBU)4 Usage of prefab staircase

100% 100%

2 2

-

32 (MAX 30)

TOTAL (PART 3)

TOTAL IBS SCORE: 45.29 + 20 + 30 = 95.29%

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conclusion With an IBS score of 95.29% the 3 storey apartment has reached an optimal use of the IBS System. This implies a clear understanding of components that are manufactured in a controlled environment has been applied to the design of our building.

The IBS systems applied include precast column and beams, precast hollow core slabs, precast concrete wall panels, prefabricated steel roof truss, prefabricated staircase and prefabricated toilet pod which have contributed to our IBS score. Moreover, the usage of standardized components including doors and windows based on MS 1064, together with repetition of structural layout further adds on to the value of IBS score.

Throughout this project, we have managed to understand the advantages of this building system in modern construction, providing a reduced construction time, cost and dependency on foreign workers, while increasing quality of buildings and systematic of site working environment. However, there is the need to reduce the knowledge gap between the government and IBS players, and further research should be done to educate the new and existing IBS players on the various opportunities of IBS usages in Malaysia.

66

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Department of Standards Malaysia (2003). Guide to Modular Coordination in Building Part 5: Coordinating Sizes and Preferred Size for Windows and Doors, Cyberjaya, Malaysia.

Department of Standards Malaysia (2003). Guide to Modular Coordination in Building Part 10: Coordinating Sizes for Reinforced Concrete Components Cyberjaya, Malaysia.

CIDB, IBS Strategic Plan 1999-2003. Construction Industry Development Board (CIDB), Kuala Lumpur 1999, pp:4-6 IBS Survey. Construction Industry Development Board (CIDB), Kuala Lumpur 2003 Ching, F., & Mulville, M. (2014). building construction illustrated. Chichester: Wiley.

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a building technology project

taylor’s university