School of Architecture, Building and Design Bachelor of Science (Architecture)
BUILDING TECHNOLOGY I BLD61403
PROJECT 1: INDUSTRIALISED BUILDING SYSTEM TUTOR : Mr. Khairool Aizat Aimuni Khalidah A Bakar Chin Vin Yan Kimberly Ann Aussie Nurul Atika Binte Mohd Gazali Ong Tun Cheik Rhianna Mae Storey
0326074 0320311 0325881 0323246 0319939 0325369
CONTENTS 1.
INTRODUCTION TO IBS
2.
INTRODUCTION TO APARTMENT
3.
DRAWINGS
PAGE 3 4-5
PAGE 5. PRECEDENT STUDY
33
6. FABRICATION PROCESS
34- 36
7. CONSTRUCTION METHOD
37 - 39
8. JOINT DETAILING
40 -43
9. SCHEDULE
44-48
10. IBS SCORE
49
11. CONCLUSION
50
12. REFERENCE
51
6-22
3.1 GROUND FLOOR PLAN 3.2 FIRST FLOOR PLAN 3.3 SECOND FLOOR PLAN 3. 4 ROOF PLAN 3.5 ELEVATIONS 3.6 CONSTRUCTION DRAWINGS 3.7.1 LOWER GROUND FLOOR PLAN 3.7.2 GROUND FLOOR PLAN 3.7.3 PRECAST CONCRETE SLAB PLAN 3.7. 4 ROOF TRUSSES PLAN 3.7.5 SECTION A-A’ & B-B’ 3.7.6 ISOMETRIC VIEW 4.
PROPOSED SYSTEM & COMPONENTS
23-32
2
1.0 INTRODUCTION TO INDUSTRIALISED BUILDING SYSTEM IBS
Industrialised Building System or better known as IBS amongst the construction and built communities is the use of prefabricated components in building construction. The construction itself can be manufactured in controlled environment, either on site or off site. Set up in the 1960’s, IBS begun as an initiative to speed up the delivery time while building affordable quality houses. However, the application and adoption of this method in the local construction industry, is still relatively low compared to the developed countries. This was despite the perennial problems besetting traditional construction methods which include time delay, cost overrun, and waste generation. The Malaysian government nonetheless sees IBS as the new way forward in the construction industry. Principles ● ● ● ● ●
Usage of prefabricated and precast components Off-site production of components The use of standardised components Repeatability Design using modular-coordination
concept
There are six main IBS systems identified as being popularly used in Malaysia, namely pre-cast concrete framing, panel and box systems, formwork system, steel framing system, timber framing system, blockwork system, and innovative system. Known in maintaining its consistent quality, the IBS system maintains its standards due to factors where majority of its systems are to be manufactured in production line of the factory. Often misinterpreted with a negative image due to its lack of aesthetic value architecturally, the benefits of IBS systems outweighs its barriers, making it still a favourable choice among the built communities.
Content
Scoring
System
(IBS
Score)
●
Part 1: Structural Systems (max. score 50 points) Eg: P.C. concrete beams & columns, steel, prefabricated timber.
●
Part 2: Wall Systems (max. 20 points) Eg.: P.C. concrete panel, glass, dry partition, block work, etc
●
Part 3: Other Simplified Construction Solutions (max. score 30 points) Eg.: Usage of simplified construction solutions (standard components based on MS 1064 and repetition of structural layout)
The IBS Scoring System is a simple yet effective method of determining a good project in regards of IBS factors. It is recommended that IBS may be a suitable option depending on the construction type, methodologies, site personnel experience and the IBS fabricator
Advantages ● ● ● ● ● ● ● ● ●
Of
IBS
Shorter construction time Cost savings Saving in labour Less labour at site Optimised use of material Higher quality and better finishes Flexibility Increased site safety and neatness Environmentally friendly 3
2.0 INTRODUCTION TO APARTMENT
INTRODUCTION The apartment consist of 3 floor which built total of 6 units. The building design is based on industrialized building system yet it give an aesthetic value by adding brick on the facade. The idea of expose the material is to showcase the beauty of rawness yet it embrace the IBS. 4
2.0 INTRODUCTION TO APARTMENT
3 storeys 2 units per floor ( 3 bedrooms, 2 Bathroom) Sqm : 97.7m2 Exterior: precast concrete wall and precast brick wall Interior: partitioned by drywall system Precast concrete skeleton structure Steel roof trusses for roof framing 1 flight of precast staircase per floor 2 extended precast balcony
UNITS FLOOR PLAN SCALE 1 : 100 5
3.0 DRAWINGS
GROUND FL PLAN SCALE 1 : 100 6
1ST FLOOR PLAN SCALE 1 : 100 7
2ND FLOOR PLAN SCALE 1 : 100 8
ROOF PLAN SCALE 1 : 100 9
FRONT ELEVATION SCALE 1 : 100 10
BACK ELEVATION SCALE 1 : 100 11
RIGHT ELEVATION SCALE 1 : 100 12
LEFT ELEVATION SCALE 1 : 100 13
LOWER GROUND FLOOR PLAN CONSTRUCTION DRAWING SCALE 1 : 100 14
GROUND FLOOR PLAN CONSTRUCTION DRAWING SCALE 1 : 100 15
PRECAST CONCRETE COLUMNS PLAN CONSTRUCTION DRAWING SCALE 1 : 100 16
PRECAST CONCRETE BEAMS PLAN CONSTRUCTION DRAWING SCALE 1 : 100 17
PRECAST CONCRETE SLABS PLAN CONSTRUCTION DRAWING SCALE 1 : 100 18
ROOF TRUSSES PLAN CONSTRUCTION DRAWING SCALE 1 : 100 19
SECTION A-A’ SCALE 1 : 100 20
SECTION B -B’ SCALE 1 : 100 21
ISOMETRIC VIEW N.T.S. 22
4.0 PROPOSED SYSTEMS & COMPONENTS 4.1 Precast Concrete Systems 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. These components are manufactured by industrial methods based on mass production in order to build a large number of buildings in a short time at low cost.
Types of Precast Systems : Precast systems can be divided into the following categories depending on the load-bearing structure : ●
Large-panel systems Refers to multi-storey structures composed of large wall and floor concrete panels connected in the vertical and horizontal directions so that the wall panels enclose appropriate spaces for the rooms within a building. Horizontal elements act as diaphragms that transfer the lateral loads to the walls.
●
Frame systems Precast frames can be constructed using either linear elements or spatial beam-column sub-assemblages
●
Slab-column systems with walls These systems rely on shear walls to sustain lateral load effects, whereas the slab-column structure resists mainly gravity loads.
●
Mixed systems
Precast concrete building systems are becoming a popular choice for many construction projects in Malaysia due to the fact that it allows for various design approaches and brings benefits to everyone in the construction team. Steel reinforcements are used to improve strength and durability of concrete. Steel offers high tension and shear strength to make up for what concrete lacks and behaves similarly to concrete in changing environments, which means it will shrink and expand with concrete, helping avoid cracking. This type of construction requires a restructuring of entire conventional construction process to enable interaction between design phase and production planning in order to improve and speed up construction
Advantages of using the precast system include :
Components of Precast Concrete System Image Source : http://equusdesign.com/web-pages/precast.htm
Main Features of System : ● ● ● ●
The division and specialization of the human workforce The use of tools, machinery, and other equipment, usually automated, in the production of standard, interchangeable parts and products Compared to site-cast concrete, precast concrete erection is faster and less affected by adverse weather conditions Plant casting allows increased efficiency, high quality control and greater control on finishes
● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
Fast Construction Scheduling Advantages Aesthetic Variety High Quality Low Maintenance Effective Pricing Safety on Site Interior Design Flexibility Efficient Design Strong Finish-Approval Process Construction Speed All-Weather Construction Efficient Erection AII-In-One Components Easy Handling Shape and Design
Disadvantages of using the precast system include :
● ● ● ● ●
● ● ● ●
Very heavy members Camber in beams and slabs Very small margin for error Connections may be difficult Because panel size is limited, precast concrete can not be used for two-way structural systems. Economics of scale demand regularly shaped buildings. Joints between panels are often expensive and complicated. Skilled workmanship is required in the application of the panel on site. Cranes are required to lift panels
23
4.0 PROPOSED SYSTEMS & COMPONENTS 4.1.1 Components of Proposed Precast Concrete System
There are three basic configurations of large-panel buildings depending on wall layout: ●
Cross-wall systems Cross walls are load bearing walls whereas the facade walls are non-load bearing. This system is suitable for high rise buildings
●
Longitudinal wall systems Cross walls are non-load bearing whereas longitudinal walls are load bearing walls. This system is suitable for low rise buildings
●
Two-way systems Combination of the above system with all load bearing walls can also be adopted
4.1.1.1 Architectural Precast Concrete Wall Panels Precast concrete walls serve two purposes : ● ●
Stability - holding slabs in place As walls or boxes surrounding staircases and lift shafts
Walls can be classified as infill or cantilever : ● ●
Infill walls rely on contiguous composite action with the beam and column frame Cantilever walls or boxes act as deep beams to which the frame is attached
Load-bearing wall structures are typically used in low and medium-rise residential buildings. These systems are particularly beneficial when a large quantity of typical housing is required, which allows for the greatest standardization of components. Advantages of using Precast Concrete Walls : ● ● ● ● ● ● ●
Low initial cost Efficient set up allowing for quick enclosing of structure Continuous construction through variable weather Panel’s long-term durability and low maintenance requirement Installment requires less scaffolding or formwork Straightforward installation of panels and no need to provide joints in precast construction Flexibility in wall design
Transportation of panels have to be handled properly and there is a requirement of special equipment, cranes and skilled workers during precast construction.
Suitability of Proposed System in Building: Component used in building : Longitudinal wall panel system Reasons : ● ● ●
More appropriate for low-rise buildings Load is distributed to both vertical and horizontal components Dry wall system is used for interior wall fill
Dry Wall Brick Wall Plan View
Precast Concrete Wall
Why Drywall? Dry construction Speed of installation NW Isometric View Examples of Precast Concrete Wall Panel Image source :http://precast.org/wp-content/uploads/2014/08/Precast-Concrete-Wall-Panel-Install.jpg
Lightweight Flexibility Sound insulation
24
4.0 PROPOSED SYSTEMS & COMPONENTS 4.1.1.2. Precast Concrete Beams and Columns
Precast Columns
A complete precast concrete structural system offers tremendous advantages and value. Precast columns and beams provide a flexible solution to the structural component of your project. A wide range of options is available for creating the perfect system to achieve the size and shape required for the building.
Columns are available in a range of shapes, sizes and finishes, can be circular or square and are designed to incorporate any additional features or fittings. Single storey columns are generally 2.5m - 4m high. Beams bear directly on top of these units with a dowelled connection between them. Multi storey columns are cast with corbels or alternative connections at locations to suit the beams at intermediate levels.
Advantages of using a precast framing system : ● ● ● ● ● ● ●
Precast beams and columns provide unlimited flexibility in design, shape and application. They are extremely durable compared to alternative building materials. Beams & Columns work well with other precast components such as Wall Panels and Hollowcore floors to form a Total Precast Precast prestressed beams and columns provide a clean, finished look for the structural component of the building Ideal framework for hanging precast panels Fast construction Structural stability
Types of Precast Columns : ●
Edge columns – symmetrical in one direction.
●
Internal columns – symmetrical in all directions.
●
Corner columns – not symmetrical at all.
Types of Precast Columns http://www.scielo.br/img/revistas/lajss/v8n4/a02fig01.jpg
Suitability of Proposed System in Building: Precast Column Construction http://precast.magicrete.in/images/beams_and_columns.png
Types of Precast Framing System : ●
●
Precast beam-column sub-assemblages Have the advantage that the connecting faces between the sub-assemblages can be placed away from the critical frame regions Linear Elements Connecting faces placed at the beam-column junctions. Beams can be seated on corbels at the columns, for ease of construction and to aid the shear transfer from the beam to the column. Beam-column joints accomplished in this way are hinged
Component used in building : Single Storey Corbel Column Every column consists of corbels depending on position of column and placement of load to be carried.. Reason : ● ● ●
Structural Stability Corbel design enables column to bear structural load Weight from other components transferred from corbels down Into core column
Image Source : http://www.scib.com.my /images/product/precast_column/column_type.gif
25
4.0 PROPOSED SYSTEMS & COMPONENTS Precast Beams Beam and beam shells are both used for suspended flooring. Beams are typically used as ledges for other forms of precast flooring to sit on and are generally manufactured to suit each particular situation. There are two main categories of beams: 1.
Internal beams – where floor loading is approximately symmetrical
2.
External beams – where floor loading is predominantly non-symmetrical
Corbel Column in Building
Wall panel Slab
L-Shaped Beam Precast Beam System https://theconstructor.org/wp-content/uploads/2012/03/clip_image00221.jpg
Corbel Column
Exterior Wall Section Corbels provide support to beams which support wall panels and slabs
Types of Precast Beams : ●
Tee Beams
Tee beams (either single or double) cover the span range beyond slab-type members such as hollowcore planks. Tee-beams are a very efficient structural shape. The units are generally cast with straight strands or deflected strands, depending on design considerations. The tee-beams are the basis for the design of economical fire rated structures where construction time, long spans or heavy loadings are important cost influences.
26
4.0 PROPOSED SYSTEMS & COMPONENTS ●
●
Inverted Tee-Beams
Suitability of Proposed System in Building:
Generally use for flooring systems like being an infill where they provide a ledger for precast floor units to sit on. Inverted tee -beams are structurally similar to a standard single tee-beam.
Component used in building : Rectangular Beams and L-Shaped Beams
Get their name from the end profile. These beams are generally used to spam clear sections and are reinforced or prestressed ●
Reason :
Rectangular Beams
L-Beams
● ●
L-shaped beams used for exterior beams and used to bear load of wall panels Rectangular beams used as interior beams and load is spread equally through longitudinal section beam
L beams have an L-shaped profile which provides a ledge for a precast flooring system to sit on. These beams are generally used to span clear sections and are reinforced and or prestressed. ●
Beam shells This is a complementary composite system of precast elements that contain all the positive main beam reinforcement and most/all of the stirrups in a minimum volume of concrete for economy and ease of handling. They are generally ‘U’shaped and mostly used in conjunction with precast flooring such as hollow core or permanent formwork panels to eliminate on site forming.
●
L-Shaped Exterior Beams in Buildin
Aashto Beams
Types of Precast Beams Image source: http://frontdesk.co.in/big/cm/beams.jpg
Rectangular Beams in Building
Tee Beam Image source: https://www.gunungsteel.com/images/stories/gamba r_teknik/big/t-beam-b1.jpg
27
4.0 PROPOSED SYSTEMS & COMPONENTS 4.1.1.3. Precast Concrete Slabs
Single Tee Slab Single T beam is a loax bearing structure that resembles one T beam connected to a slab. They are used to provide spans ranging from 30 to 100 feet. Single-tees may be placed flange to flange. Span length ranging from 3.5m to 30m Suitability of Proposed System in Building. Component used in building : Hollow Core Slab Reasons :
Type of Precast Concrete Slabs https://i.pinimg.com/736x/3b/7d/94/3b7d949656603fc6bfec77bc17b9c31e--what-to-use-precast-concrete.jpg
● ● ●
Provide long spans with cross-sections that reduce the height of the building, saving material cost inorganic composition enhances fire protection
Precast Slabs are cast in a factory environment and are a more efficient and cost friendly option for producing floor panels and roof deck panels. This precast component includes the following prestressed concrete options : Solid Flat Slab A flat slab is a two way reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns. The column tends to punch through the slab in Flat Slabs, which can be treated by three methods : 1. With drop panel 2. With column head 3. With both
Hollow core slabs https://is.alicdn.com/img/pb/952/998/265/12838 42496609_hz-myalibaba-web6_2543.JPG
Hollow Core Slab Also known as a voided slab, Hollow core slabs are a form of precast slab of prestressed concrete typically used in the construction of floors in multistorey apartment buildings. The precast concrete slab has tubular voids extending the full length of the slab, diameter is 2-3 to 3-4. The slabs are 120cm wide with standard thicknesses between 15cm and 50cm. The size of these elements will typically range in width from 600 to 2400mm, in thickness from 160 to 500mm, and can be delivered in lengths of up to 24m.
Slab Layout in Building
Voids in the hollow core slabs reduce weight and cost and can conceal or cover electrical or mechanical runs. Double Tee Slab Two symmetrically placed beams interacting with a slab forming in one section with a “double tee” shape made in precast, prestressed concrete. Resistant to moisture and corrosion. Parking garages, office buildings, commercial buildings, factories, industrial buildings are all ideal applications. Each double tee slab is normally 2400mm wide. Precast beams, precast walls, poured concrete beams and walls, masonry walls, insulated concrete forming system walls and structural steel beams are all suitable for use with double tee slabs as load bearing systems.
Local precasters can help determine which sizes, shapes and styles of components will best suit any individual commercial building project
28
4.0 PROPOSED SYSTEMS & COMPONENTS 4.1.1.4 Precast Concrete Staircase Three options are available for precast staircases: ● ● ●
A single precast unit containing all the flights and landings Separate precast flights and landings Parts of the flights and landings are made in one piece
Staircase Location in Building Plan
Image source : http://bbp.style/PUBLIC/images/website-images/australprecast/AP-Stairs-ProductImage-02-NAT.jpg Advantages of using Precast Staircase : 1. 2. 3. 4.
Provide an unobstructed, early, secure and instant work platform during construction Quick installation time frame Elimination of site shuttering and scaffolding, resulting in reduced construction site costs Quality controlled manufacturing environment allows for repetition of individual components
Suitability of Proposed System in Building Component used in building : U Shape Stair Single Middle Landing Reason : ● ● ●
Suitability with building layout Limited stair space Easy placement and less needs for jointing systems
Figure : U Shape Stairs
29
4.0 PROPOSED SYSTEMS & COMPONENTS 4.2. Precast Brick Wall Panel System
● ● ● ● ● ● ●
Brick-faced precast panels offer all the advantages of the natural materials, but provides a great alternative to traditional construction methods. Brick-faced precast cladding also eliminates most of the concerns associated with traditional brick construction. ● ● ● ● ● ● ● ● ● ● ●
Cost efficiencies Speed of construction Simplified logistics Cost-effective production of large components Speedy site times No scaffolding/external hoisting Reduction of wet trades on site Acoustic benefits Fire-resistant Reduction of waste Can incorporate pre-installed windows
Image source : http://forterra-precast.co.uk/wp-content/uploads/wall-stacking.png
Can be manufactured in large sizes; typically grid width x storey height – this lowers cost and increases the speed of enclosure compared to hand-set brickwork Reduces site programme and thus site prelims Reduces number of site movements and waste; tidier, safer environment Achieves building weather tightness much quicker No scaffolding required Very low maintenance and lifecycle costs Offers reduced overall cladding zone (compared to a conventional brick/block cavity wall), resulting in greater net lettable area
Suitability of Proposed System in Building. Component used in building : Precast Brick Wall Panels Reason : ● ●
https://www.jacekpartyka.com
J
Allowance for variation aesthetic value in building Efficient method compared to traditional brick method
Front Ellevation
Left Elevation
Brick-faced cladding advantages: ● ● ● ● ● ● ●
Offers designer more scope, as anti-gravity features can be pre-moulded, avoiding need for cumbersome secondary support on-site Enables complex features such as arches without need for centres and site cutting and fitting Allows multiple brick finishes in each panel Can include windows, doors etc (as with all precast cladding) Panels can be pre-insulated Components accurately manufactured off-site Greater quality control
Back Elevation
Right Elevation Figure : Elevations of building showing brick wall panels
30
4.0 PROPOSED SYSTEMS & COMPONENTS 4.3 Steel Framing System
A truss is essentially a triangulated system of straight interconnected structural elements. The most common use of trusses is in buildings, where support to roofs, the floors and internal loading such as services and suspended ceilings, are readily provided. The main reasons for using trusses are:
This IBS is commonly used with precast concrete slabs, steel columns/beams and steel framing systems, and is used extensively in the fast-track construction of skyscrapers. Apart from that, it is extensively used for light steel trusses consisting of cost-effective profiled cold-formed channels and steel portal frame systems as alternatives to the heavier traditional hot-rolled sections Advantages of Steel Framing Systems : ● ● ● ● ● ●
The large-scale benefit of utilizing steel in residential construction is the longevity and durability of the material itself Structurally Light Shorter construction timeline Takes the element of human error out of the equation Cost savings Versatility of steel allowing for variety in design
Disadvantages of Steel : ● ●
They lose strength at high temperatures, and are susceptible to fire. They are prone to corrosion in humid or marine environments.
●
Long span
●
Lightweight
●
Reduced deflection (compared to plain members)
●
Opportunity to support considerable loads.
●
To carry the roof load
●
To provide horizontal stability.
Advantages of Roof Trusses : ● ● ● ● ● ●
Cost effective Quick installation Heavy equipment to lift not required Span across long distances High stability due to shape Triangle shape allows weight that is applied to sides to be redistributed down and away from center
Disadvantages of Roof Trusses :
4.3.1 Components of Proposed Steel Framing System 4.3.1.1 Steel Roof Trusses
● ● ●
High Fabrication cost Rusting may occur High heat conductivity of metal requires careful incorporation of insulation into the roof structure
Common types of Steel Roof Trusses :
Left : https://sc01.alicdn.com/kf/HTB1tKjlFpXXXXaiaVXXq6xXFXXX0/200459693/HTB1tKjlFpXXXXaiaVXXq6xXFXXX0.jpg Right : http://bmmetalroofing.com/wp-content/uploads/2014/06/NuTruss_Brochure-2_11.jpg
Image source : http://www.barntoolbox.com/images/RoofTrussTypes.jpg
31
4.0 PROPOSED SYSTEMS & COMPONENTS Suitability of Proposed System in Building. Component used in building : Mono-Pitch Roof Steel Structure Reason : ● ●
Lightweight structure compared to the other precast components Simple yet effective form of steel roof truss
Roof over Trusses
Steel Roof Trusses without Roof
Back elevation of Roof Trusses
32
5.0 PRECEDENT STUDY
1.
2. MELROSE COMMONS II APARTMENT
SERI KASTURI, SETIA ALAM LOCATION: Bandar Setia Alam, Shah Alam, Selangor, Malaysia
LOCATION: Melrose Ave, Bronx, NY,USA COMPLETE YEAR : 2001
COMPLETE YEAR : 2015
PRECASTER : Oldcastle Building Systems
PRECASTER : Setia precast Sdn. Bhd.
ARCHITECT : Danois Associates, New York City
3-bedroom, 2-bathroom unit
FACT : 130,000 SF hollowcore
10 floor - 950 built up
KITCHEN BEDROOM 2
DINING ROOM LIVING ROOM
MASTER BEDROOM
BEDROOM 1
INTRODUCTION Seri Kasturi Setia Alam is a middle-cost apartment developed by S P Setia and using precast construction method that supply by Setia Precast sdn. Bhd. The apartment used precast concrete which suitable in a humid context in Malaysia.
Precast
DESIGN
INTRODUCTION
The design of the apartment are horizontal and vertical repetition structure. Hence, it achieve a good design of modularity. Next, The whole building is repetition of floor to floor height all the way to 10st floor. Beside that, the design of building is base on Malaysia Standard (MS1064). Butterfly roof is design because of the climate in Malaysia.
Melrose Commons II, a 30 unit multifamily affordablehousing in New York City .The homes feature an all-precast concrete design that the developer agreed to try after meeting with the precaster and being convinced of the benefits. Despite the conveniences that ease the construction process, the building also achieve the aesthetic value that fit into the context. Beside that, the building had awarded multiple awards for being industrialized building system that benefit in the construction industry.
PRE-ASSEMBLE BRICK PANEL To achieve the “masonry” aesthetic effect, a brick fecade was pre-assemble on the external wall panel. Beside that, precast lintel and cornice were added to enhance the detail. PRECAST CONCRETE WALL PANEL were installed for internal partition and also act as a parti wall. Despite that, it also act as a load bearing walls which supported the whole structure.
HOLLOWCORE SLAB were plank over the precast concrete wall panel. To joint both component together, i-Beam were installed into the pre-assemble brick panel’s column. 33
6.0 FABRICATION PROCESS 5.1 Precast Concrete System IBS methods focuses on the concept of prefabrication where a single housing unit is broken into different components such as the floors, walls, columns, beams and roof, and having these components prefabricated or manufactured in modules in a factory. A well established practice, the production of precast concrete has been developed to regulate the quality of precast concrete production processes. With efficiency and cost benefits in production, multiple modular panels are easily produced in a day. Process: ●
Setting up formwork The formwork used for fabricating precast concrete is made of sturdy steel members that are locked into place on flat steel casting beds. Precasting allows the use of high quality formwork such as vibrating casting tables and accurate positioning of inserts, where the formwork can retain tight dimensional tolerances over repeated use.
●
Providing
blockouts
and
grout
ports
for
dowel
bars
and
tie
bars
●
Providing panel undersealing Cement grouts are primarily used for the undersealing of precast. Undersealing helps will voids that occurring voids that may exist under the panel and ensure full contact.
●
Placing concrete Once the formwork is ready, concrete is delivered to the formwork using a transit mixer or buckets within the precast plant complex. Typically, there are two concrete types and placement processes, namely slump concrete and SCC.
Image source : https://www.nap.edu/read/22710/chapter/11#89 Image source : https://www.nap.edu/read/22710/chapter/11#89
●
Installation of hardware (Reinforcement, prestressing steel) As reinforcement is placed in both directions and typically placed in two layers, nominal reinforcement is required to mitigate the concrete stress encountered in delivery. Ducts are positioned straight and not allowed to bow under the weight of concrete as it is poured into the formwork.
Slump concrete requires moving the concrete manually within the formwork and consolidated using a spud vibrator. It is then finished with a metal straightedge or hydraulic powered roller screed. SCC however is deposited across the formwork without compaction effort or manual manipulation.
Image source : https://www.nap.edu/read/22710/chapter/11#89
Image source : https://www.nap.edu/read/22710/chapter/11#89
34
6.0 FABRICATION PROCESS ●
Controlled pouring environments in the factory reduce concrete curing times through the use of temperature control and advanced mix design, including low water to cement ratios. The placement rates are maintained as panel production is not affected by external factors such as weather conditions and traffic delays. Therefore, concrete is usually produced as needed on a just-in-time basis
●
Stripping forms To allow the next set of panels to be fabricated, a timeframe of 15 to 20 hours is allowed where the panels are stripped of formwork.
●
Conducting QA/QC activities The precast system typically ensures concrete durability and strict tolerances to minimise installation-related issues. Quality Control carries out tests and certifications assuring the correct specification of materials and equipment meet the project specification requirement while Quality Assurance is usually done by third-party organisation.
Image source : https://www.nap.edu/read/22710/chapter/11#89
Image source : https://www.nap.edu/read/22710/chapter/11#89
●
●
Applying finishing details The day-old panels may be moved to other areas where finishing details can be taken care of, such as: ○ Cleaning of blockouts ○ Installing foam strips ○ Applying project ○ Cutting pretension tendons ○ Checking for damage
●
Delivery The erection sequence would determine the order of transport where careful planning can minimise transport and costs. Large linear precast concrete elements can be transported by overhead cranes directly from the production shop and loaded onto trucks to site.
●
Installation Ready for assembly, the IBS components are assembled with the assistance of a crane. As specialised lifting equipment are required, specialised contractors will be needed. The final unit of the building is now assembled and ready for occupation.
Cutting and storing panels Once the finishing details and curing membrane has been completed, the precast concrete is moved for storage. It is cured at the plant and typically stored for a week to a few months until installation.
Image source : https://www.nap.edu/read/22710/chapter/11#89
Image source : https://www.nap.edu/read/22710/chapter/11#89
35
6.0 FABRICATION PROCESS 5.1.1
Components
5.2
Steel
Framing
System
Precast Hollow core Slab Processed under quality controlled conditions in specialised environments, hollow core slabs can be produced. The dry cast production system uses the extrusion method of forming precast voided slabs thus slab extruders are used.
Column and Beam The use of columns and beams makes an ideal framework for hanging precast panels, offering fast construction, structural stability and enhanced fire resistance.
Most steel construction is done with a type of steel called mild steel. Mild steel is a material that is immensely strong. Cutting & Drilling In the fabrication factory one of the first operations is to cut the sections to length and profile the plates to the desired size or shape. Circular Saws are used for cutting to length. Drilling & Punching To allow system to be rapidly bolted together on site, all holes are pre drilled or punched in the fabrication factory. For drilling, high speed steel twist bits are used. The rotating bit cuts through the steel and the metal being removed during the process forms swarf (the curls of metal that spiral off during machining). The swarf travels up the flutes , which run up the side of the bit. Shot Blasting Once the steel is cut to preferred length it will undergo shot blasting process. It is used for surface preparation which is an important part of the fabrication process, that is essential to provide a suitably clean finish for welding and subsequently producing a keyed surface ready to accept paint. Shot is fired at the steel making the force of the shot against the surface displaces dirt and scale.
Precast Wall Precast panels are manufactured in a manufacturer plant by casting the concrete into the formwork. It will then be ready to install after it is delivered to the jobsite where each panel is designed according to engineering standard to withstand for each structural load.
Primers Prefabrication primers are then applied, immediately after blast cleaning, to maintain the reactive blast cleaned surface in a rust free condition through the fabrication process until final painting can be undertaken. When paint is sprayed onto this clean abraded surface it adheres well and provides a longer life for the paint system.
Staircase Able to be produced as straight flights with separate or attached landings, precast staircase offers finished landings and hidden connections with design practicability. Installation is efficient and ready to use with immediate access, improving site safety.
36
7.0 CONSTRUCTION METHOD The IBS method differs from the conventional construction method. Known for its multiple benefits such as shorter construction time, material saving and immunity to weather changes, IBS acts as an alternative approach to the existing conventional building system. IBS construction stages :
COMPONENT PRODUCTION
COMPONENT DELIVERY CONNECTING
M&E WORKS
COMPONENT ASSEMBLY
LIFTING
FIXTURES INSTALLATION
FINISHING
PLACING
7.1 CONSTRUCTION METHOD & SEQUENCE 7.1.1.
LOWER
GROUND
Starting with the excavation of the site, it is levelled to allow straight alignment of precast components. Pad footings with protruding column stumps are then assembled on site followed by ground beams. Precast columns are installed on top of the precast stumps by bolting connections where the baseplate can be welded to the bottom of the embed. The slab is then installed and the lower ground construction is complete.
1.
3.
2.
4.
5.
37
7.0 CONSTRUCTION METHOD 7.1.2
GROUND
FLOOR
The L-beams on ground level are rested on the column corbel via steel angles that are welded to metal plates casted into the beams and columns itself. Once the skeletal structure is intact, the wall panels are slotted into place. Non-loadbearing walls such as exterior precast concrete walls and interior drywalls are installed. The staircase with anchor plates are then slotted onto the landing, where the gaps are grouted with cement.
1.
3.
2.
7.1. 7.1.3
FIRST
4
SECOND
FLOOR
FLOOR
The hollow core slabs are installed and supported on L-beam (exterior) rectangular beam (interior) where reinforcement bars are inserted between the slabs and grouted with cement, securing them in place. The construction sequence is repeated where the column (GF) to column (FF) are connected by metal bearing plates and embedded anchor bolts that are casted into both ends and grouted. Beams, walls and staircase are as followed.
1.
4.
The construction sequence is repeated where the column (FF) to column (SF) are connected by metal bearing plates and embedded anchor bolts that are casted into both ends and grouted. Beams, walls and staircase are as followed.
1.
2.
2.
38
7.0 CONSTRUCTION METHOD 3.
7.1.6
4.
M&E
WORKS,
FIXTURES
&
FINISHING
Lastly, M&E works and fixtures such as doors, windows and railings are installed. Finishing works for slabs and walls such as water proofing layer are carried out as well.
7.1.5
ROOF
The unit is designed with a mono pitched roof. After the construction of the superstructure, prefabricated steel roof truss are secured into the beams with connections of L-plates and bolts. The rafter supports the materials of roof claddings with beams preventing them from deflection. Pieces of corrugated aluminium are screwed onto the purlins bottom up along with rockwool insulation, vapour barrier, trapezoidal galvanised steel sheet underneath.
1.
2.
39
8.0 JOINT DETAILING COLUMN
TO
FOOTING
Pad footings with protruding column stumps are assembled on site followed where the precast columns are installed on top of the precast stumps. The column and footing are connected by bolting connections where the baseplate can be welded to the bottom of the embed, leveling the nuts on the anchor bolts. The column can be lowered in place and now bolted.
COLUMN
TO
COLUMN
Metal bearing plates and embedded anchor bolts are cast into the ends of the columns. After the columns are mechanically joined, the connection is grouted to provide full bearing between elements and protect the metal components from fire and corrosion.
Precast column
Concrete slab Concrete pour back The entire joint is dry-packed with grout after alignment
Shins
Baseplate over non-shrink grout
BEFORE ASSEMBLY
ASSEMBLED
GROUTED
SECTION OF PAD FOOTING TO COLUMN CONNECTION
40
8.0 JOINT DETAILING BEAM TO COLUMN
SLAB
Beams are set on bearing pads on the column corbels. Steel angles are welded to metal plates cast into the beams and columns and the joint is grouted solid.
The hollow core slabs are installed and supported on L-beam (exterior) rectangular beam (interior) where reinforcement bars are inserted between the slabs and grouted with cement, securing them in place.
TO
BEAM
&
SLAB
TO
SLAB
Metal plates cast
Rebate cast in floor slab for angle connection EDGE SUPPORT
IN-SITU CONCRETE
Bearing pads
EXTERIOR L-BEAMS COLUMN CONNECTION
INTERIOR RECTANGULAR BEAMS COLUMN CONNECTION
INTERNAL SUPPORT
41
8.0 JOINT DETAILING WALL TO BEAM
STAIRS TO SLAB
Walls are slotted into place after framing structure is intact. Wall panels are either made with grooves to be permanently fixed in but can also be bolted or welded into place. Instead of arranging the L-beam inward, the arrangement of face outward allow the slotting of the brick wall into the L-beam and helps prevent water leakage from the exterior.
The staircase with anchor plates are then slotted onto the top and bottom landing. The gaps are then grouted with cement.
Precast Brick Wall
Top landing connection
Rebate cast in floor slab for angle connection
Rebate cast in floor slab for angle connection
L-beam SECTION CUT OF EXTERIOR WALL AND BEAM
SECTION CUT OF STAIRCASE
Bottom landing connection
42
9.0 SCHEDULE
43
45
45
46
47
10.0 IBS SCORE
48
11.0 CONCLUSION In Building Technology 1, it introduces us to a more extensive study of building construction by exposing us to the latest technologies implemented in the industry today. Through this project, we enable to experience the whole process of construct an IBS building by design a 3 storeys residential apartment, understand the construction method of IBS, calculate the IBS score and experimental with model making. The process of design is needed to implement the MS 1064 in order to achieve the required modularity system. Hence, the process of design is critical and yet need to be achieve with the practicality. Beside that, we were to purpose the industrialized building system that suit the most for our design. Thus, we get to understand the methodology of IBS construction and the details that joint each components. After proposing the system, we then need to calculate the IBS score for our apartment. From there, we enable apply the calculation method of Part1, 2 and 3 that we learn prior in the class. Last but not least, model making enable for us to experiment the workability of IBS construction in our building and also understand the construction sequence of the IBS. In this project, many of the detail need to be take note in order to minimise mistake. Therefore, teamwork and communication is needed. Aside from that, this project had introduced us the latest technology in the our building industry and also allow us to achieve a design which is practical, sustainable, and efficient.
Final sectional model
50
12.0 REFERENCES 1.
Precast Concrete Building Systems - Precast Wall Panels, Column & Beam. (2017, July 17). Retrieved October 08, 2017, from http://www.ultraspan.ca/building-with-precast/
2.
Industrialized Building System (IBS). (n.d.). Retrieved October 08, 2017, from http://www.malaysiaconstructionservices.com/services/industrialized-building-system-ibs
3.
SAHIL KUMAR, Student at LPU Follow. (2016, May 14). Prefabricated wall panel. Retrieved October 08, 2017, from https://www.slideshare.net/SAHILKUMAR157/prefabricated-wall-panel
4.
(n.d.). Retrieved October 08, 2017, from http://www.dubaiprecast.ae/system
5.
A. (2013, July 28). Precast concrete. Retrieved October 08, 2017, from http://www.yourhome.gov.au/materials/precast-concrete
6.
PRECAST COncrete STRUCTURE. (n.d.). Retrieved from http://paradigm.in/wp-content/uploads/2015/01/5-PRECAST.pdf
7.
Columns And Beams, Precast Columns And Beams. (n.d.). Retrieved October 08, 2017, from http://www.oreillyconcrete.com/products/columns-beams/
8.
Mishra, G. (2017, September 12). Types of Precast Components in a Building. Retrieved October 08, 2017, from https://theconstructor.org/concrete/types-of-precast-components-in-a-building/6325/
9. 10.
Sagar Shah Follow. (2016, April 23). PRECAST BUILDING SYSTEM. Retrieved October 08, 2017, from https://www.slideshare.net/SagarShah118/precast-building-system Concrete, C. (n.d.). Precast Concrete Columns and Beams. Retrieved October 08, 2017, from http://www.creaghconcrete.co.uk/products/precast-frames/precast-concrete-columns-beams.html?p=198
11.
Brick-faced Panels. (n.d.). Retrieved October 08, 2017, from http://techrete.com/products/finish/brick-faced-panels/
12.
T. (2011, September 22). Advantages and Disadvantages of Precast Concrete Construction. Retrieved October 08, 2017, from https://cw2011workshop05.wordpress.com/2011/09/22/advantages-and-disadvantages-of-precast-concrete-construction/
13.
Melrose Commons II. (n.d.). Retrieved October 08, 2017, from http://www.pcine.org/projects/project.cfm?categoryIDs=&articleID=08447A69-F1F6-B13E-838416AE5F62F91E&pageNumber=2
14.
(n.d.). Retrieved October 08, 2017, from http://www.setiaprecast.com.my/current_project_residential.asp
15.
(n.d.). Retrieved October 08, 2017, from http://www.creativeptsb.com/project-references.htm
16.
Http://ljournal.ru/wp-content/uploads/2016/08/d-2016-154.pdf. (2016). doi:10.18411/d-2016-154
17.
Http://www.astm.org/JOURNALS/FORENSIC/PAGES/JFS2004186.htm. (2004). Journal of Forensic Sciences, 49(6), 1-1. doi:10.1520/jfs2004188
51