SEM 3

1. SCHOOL OF ARCHITECTURE, BUILDING & DESIGN
BACHELOR OF QUANTITY SURVEYING (HONS)
CONSTRUCTION TECHNOLOGY III (BLD60304)
GROUP ASSIGNMENT
GROUP MEMBERS:
1. WONG JIA JING (0327221)
2. YEAP PHAY SHIAN (0322243)
3. YEE JYH LIN (0322408)
LECTURER: IR. CHAI VOON CHIET

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TUTORIAL SESSION: SEC 2

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TABLE OF CONTENT
No. Content Page No.
1 1.0 Introduction
1.1 Industrialized Building System (IBS)
1.2 Formwork System
1.2.1 Steel Formwork System
1.2.2 Tunnel Formwork System
3-4
2 2.0 Tunnel Formwork Construction Process
2.1 Casting Process of Tunnel Formwork System
5-7
3 3.0 Advantages and Disadvantages of Tunnel Formwork System
3.1 Advantages
3.2 Disadvantages
8-9
4 4.0 Case Study
4.1 Case Study I – The Paramount Buckhead in Atlanta
4.2 Case Study II – Rohan Abhilasha in Pune, India
10-13
5 5.0 Conclusion 14-15
6 6.0 References 16

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1.0 INTRODUCTION
1.1 INDUSTRIALIZED BUILDING SYSTEM (IBS)
Industrialized Building System is a technique of construction whereby the components
are manufactured and in a controlled environment, either at site or off site, placed and
assembled into construction works.
Generally, there are five types of IBS in Malaysia that are:
 Pre-cast concrete frames
 Formwork systems
 Steel frame systems
 Prefabricated timber frames
 Block work systems
1.2 FORMWORK SYSTEM
Formwork serves as a mould for concrete structural components in which fresh concrete
is poured only to harden subsequently. IBS formwork system includes steel, aluminum,
timber formwork system and so on.
Tunnel formwork system is a type of steel formwork system.
1.2.1 Steel Formwork System
Steel formwork system is considered as one of the ‘low-level’ IBS as the site casting is
still required for the system. As such, the issue of structural quality control arises. Despite
this, tunnel formwork system is still better than the conventional construction process as
the finishes is of better quality, constructions process is faster, costs saving and less site
labours and materials are required. Steel formwork does not absorb moisture from
concrete and it does not shrink or warp.

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1.2.2 Tunnel Formwork System
This report will mainly be focused on Tunnel Formwork System.
Tunnel Formwork System is classified as a type of steel formwork system. Known as a
modern method of construction (MMC), it is used widely in the construction of cellular
structures that consists of high degree of repetition, for instance, private housings,
commercial developments, hotels and prisons. All of these buildings have monolithic
structures. The system creates an efficient load bearing structure for use in a wide variety
of applications. Tunnel formwork comes in half units and in the form of an inverted “L”
whereby it is bolted together at the top to form each tunnel. The articulated struts brace
the horizontal and vertical panels, thus allowing the adjustment of horizontal level of the
slab and also simplifying the process of dismantling the formwork.
This formwork system ensures the laying of base concrete and wall concrete
simultaneously. It makes sure that the surfaces subject to concrete are made of sheet
metal. The prefabricated tunnel formwork can be reused up to 600 times and it is able to
suit a variety of module sizes. A 24-hour construction cycle can be achieved and the
buildability of in-situ concrete is improved by using tunnel formwork system. Tunnel
formwork works by creating cells, which can be easily subdivided to create rooms. If
longer spans are required, tunnel forms can be extended using a mid-span section.
Diagram (a) – Tunnel Formwork System

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2.0 TUNNEL FORMWORK CONSTRUCTION PROCESS
The on-site implementation of 24-hour cycle is separated into the following operations:
i. Stripping off the previous day’s formwork.
ii. Correctly placing the formwork for the current day’s phase by a tower crane.
iii. Installation of mechanical, electrical and plumbing services.
iv. Installation of reinforcement in the walls and slabs.
v. Pouring of concrete in walls and slabs in one single operation.
vi. Heaters fired up if necessary
vii. Overnight curing starts.
viii.The engineer carries out a concrete test to ensure that the previous day’s pour has
achieved the required strength.
When a storey has been completed, the process is repeated on the next floor.

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2.1 Casting Process of Tunnel Formwork System:
1) Prefabricated wall reinforcement is placed at the correct position by crane prior to
casting the kickers.
2) As two and a half tunnel is craned in position, it is bolted together and tied.
3) The wall concrete is poured.
4) Slab reinforcements are fixed.

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5) Slab concrete is placed. The formwork system allows the tarpaulins to wrap the pour
and for the usage of butane heaters to maintain a suitable high temperature. This is so that
the concrete can reach its desired strength overnight.
6) The tunnel-formworks are removed the next day.
7) The process is repeated for the next two bays.

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3.0 ADVANTAGES & DISADVANTAGES OF TUNNEL FORMWORK SYSTEM
3.1 ADVANTAGES
 Quality
The precise, even steel face of the formwork gives a smooth and high-quality finish.
Wallpaper can be applied directly or a skim coat may be used to enhance the plastered
finish.
 Time
Construction process is simplified due to the nature of repetition and the use of
prefabricated forms so construction process is speedier.
 Costs
Monolithic construction results in saving on foundations. Tunnel formwork system
usually reduces the cost of the frame by more than 15%. Also, less labour is required. It
serves as a quicker return on investment.
 Design
Flexibility in design and layout of the building gives more freedom in the building
outlook.
 Safety
Tunnel formwork system consists of integral working platforms and edge protection
systems. It also requires less tools and equipment so accidents can be reduced on site.
 Efficient
Since it has a repetitive nature, familiarity with operations is encouraged, leading to
improve in productivity and efficiency.

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 Sustainability
The in-situ casting on site and the locally available materials can minimize transportation
impacts. Scheduled delivery and almost non-wastage produce a neater site. Furthermore,
concrete’s thermal mass coupled with the right insulation and boiler design reduces
heating costs.
3.2 DISADVANTAGES
 Costs
Tunnel formwork system has a high initial cost and equipment and machinery costs are
relatively higher due to the cranes needed for each block. Due to speedy construction,
high cash flow required.
 Dimensional Limitations
This system has low degree of modular flexibility. Lowered slab is not allowed since it
prevents the removal of formwork and suspended ceiling is required. Basement storey
cannot be constructed using tunnel formwork as the removal of formwork is not possible.
Various geometrical forms and angle are hard for special formwork to be designed.
 Coordination Issues
The high production of this system relates to the management functions. As such,
coordination problems cause delays in schedule.
 Skilled Labour
Skilled labour force is needed compared to conventional systems.

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4.1 Case Study I - The Paramount Buckhead in Atlanta
Diagram (b) - The Paramount Buckhead, Atlanta
The Paramount Buckhead in Atlanta, by The Hanover Company, Houston is a 44-storey
residential structure. It is one of the tallest residential structure ever constructed using
tunnel form and it is the third tunnel form project for the building’s owner. From this case
study, there are a few aspects that are identified:
Efficient in concrete casting
 One floor can be completed in every 3 days. Completion of shell was completed
one month ahead as per schedule.
 At the Buckhead site, it took only 5 minutes for a small crew to remove both half-
tunnel forms from the previous day’s placement and set them up at their next
location
 85% of the work uses tunnel form which allow them to fulfill the contract with “2
homes per day” requirement.

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Affordable single-family residence & apartment
 Tunnel form help reduce time to build structure because workers formed both
walls and decks in one operation hence reducing overhead cost
Refinements purpose
 Ideal for project like these that offer repetitive framing opportunities. The more
repetitive steps there are, the greater the benefit.
 Less chance of making mistake since its cycled-work based.
 For the Paramount project, Stull reports that workers could easily locate the
tunnel forms precisely each time they were moved, so the building was only 3⁄8
inch out of plumb in its 44 stories.
 Because of the smooth still skin of form, process pitching and painting on walls
and ceiling accelerates.
Speed of construction with a small crew is the most marketed benefit
 Only a few workers are required to place ask the formwork needed for an entire
floor. Workers help to give instruction to the crane operator during installation.
Tunnel-formed building require low maintenance, and it’s strong & rigid structure.
Quietness
 Strong selling point of this project.
 There is no creaking or movement in the floors, and concrete walls transmit little
sound
Require good detail planning
 To take full advantages of the system
 Design around the use of tunnel form
 Plan about daily flow of construction of this project where by labour force are
performing the same tasks each day

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4.2 Case Study II - Rohan Abhilasha in Pune, India
Diagram (c) - Rohan Abhilasha in Pune, India
Rohan Abhilasha is a residential project that used advanced tunnel form system in
Pune, India. It contains 25 towers, each having 12 residential levels with 2 ground
levels. Rohan Abhilasha is the first projects to employ the tunnel form system for
constructing the towers and the individual apartments in each tower in the area.
Tunnel form system was identified as the most suitable formwork system for the
construction of this multi-storeyed building with its speciality.
Shorter erection period permits an earlier recovery of capital
 Tunnel form allow the contractor to lay wall and slab concrete at the same
time.
 One layer is constructed with a set of formwork every day.
 Has a production cycle of 1-3 days per floor.
 Cost of financing the construction capital is considerably decreased with high
construction speed.

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Effectiveness in production and minimization of labour costs
 Reuses the formwork from housing units a few times, result in effectiveness
in production of building.
 Less labour required.
Assurance of Good Quality
 Precast products that manufactured and cured in plant such as staircases
were used.
 Made in monitored and controlled environment, therefore high product
quality and reliability.
 Result in increased productivity after erection at a very short period of time.
Strong and durable against earthquakes
 Located in country that suffers high frequency of earthquakes.
 Tunnel formwork system that creates efficient load-bearing structures which
are known as the most earthquake resistant structures were used.

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5.0 Conclusion
Different formwork systems provide a wide range of concrete construction solution that
can be chosen to suit the needs of a particular development. As compared to the
conventional formwork, tunnel formwork which is a type of modern formwork systems,
which are mostly modular, are designed for speed and efficiency. When compared in
detail, tunnel formwork system promotes one day’s cycle per floor whereas conventional
formwork system on the other hand provide a minimum cycle time of 21 days. For
quality wise, the final concrete finish quality, plastering is not required for concrete that
adopt tunnel formwork but it is necessary for conventional formwork product. Even
though tunnel formwork requires high initial cost when compared to conventional
formwork system, it is still considered as economic especially for mass housing project.
In additional to cost factor, number of time of reuse for tunnel formwork system is also
much higher as compare to the conventional one. Reuse time of tunnel formwork system
would be around 300 to 500 times whereas for conventional formwork has maximum of
only 50 times.
Through the case study that we’ve chosen to analyse, it shows evidence of the beneficial
side of tunnel formwork. Quality of concrete finish is ensured, increase efficiency of
work and improve cost effectiveness of a project.
The main reason why India apply the use of tunnel formwork is because they are the
manufacturer. Tunnel formwork system was first discovered in France. It is then
duplicated by India and manufactured in India. Therefore, India adopt the use of tunnel
formwork in most of their construction. As for Atlanta, tunnel formwork system is
applied mainly because of structurer advantage. In America, the New Madrid earthquake
zone that could have a devastating earthquake that would be felt in nearly a dozen states,
researcher say, threatening large cities such as Atlanta. In content with this, tunnel
formwork is therefore applied not only for its structurer benefit but also for time
efficiency and cost effectiveness.

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Despite the beneficial side of adopting tunnel formwork in the construction industry,
safety precaution should be taken while applying the used of tunnel formwork. Heavy
machinery and on-site management are critical factors in implementing tunnel formwork.
Therefore, safety precaution would include training session given to labours to help
improve their knowledge and skills. Employer’s responsibility towards the health and
safety of all labour in the on-site environment also plays a significant role to ensure their
action do not harm anyone while working, including themselves. Besides, maintaining a
safe working environment is also very important. Without acknowledgement of
appropriate safety precaution, coordination problem may arise and would most probably
cause remarkable delay in schedule.

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6.0 References
 https://theconstructor.org/concrete/tunnel-form-construction-technique/8574/
 http://www.concretecentre.com/Building-Elements/Walls/Tunnel-form.aspx
 http://civil-resources.blogspot.my/2010/06/formwork.html
 http://tunnelformconstruction.com/tunnel%20form.htm
 http://www.portisan.com/tunnel-formwork.html
 http://web.itu.edu.tr/~kanoglu/crs_bps_cn_tunnelformworksystem.pdf
 http://www.outinord.fr/siteanglais/indexanglais.html
 http://edition.cnn.com/2015/08/17/us/americans-earthquake-risk-usgs/
 http://www.rohanbuilders.com/blog/tunnel-form-construction-technique-at-rohan-
abhilasha-pune
 https://propstory.com/home/pune/rohan-abhilasha-wagholi-pune/
 http://www.concreteconstruction.net/projects/commercial-industrial/building-
with-tunnel-forms_o
 https://www.irjet.net/archives/V4/i3/IRJET-V4I397.pdf
 http://www.krishisanskriti.org/vol_image/07Sep201512090750.pdf
 http://www.constructionworld.in/News/In-Form/87245