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Construction technology ii report
1. SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN
BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB1524 – Construction Technology II
Scaffolding
August Semester 2013
Construction Technology II Report
Submission Date: 6thDecember 2013
Name
StudentID
Yam Yih Hwan
0305861
Low Rong Tzuoo
0304924
Janice Kong Yin Ying
0308798
Harvey Yap Zhu Guang
0309325
Wong Ha Shiong
0309640
Construction Technology II - Report
1
2. Table of Content
Page
Cover Page
1
Table of Content
2
Introduction
3
Objective
4
Methodology of Scaffolding
5-7
Safety Precautions
8 - 11
Material Used in Scaffolding
12 - 14
Suitability of Usage
15 - 18
Conclusion
19
References
20 - 21
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3. Introduction
On 26thSeptember 2013, along with my group mates, we went for a site visit in a
construction site located at SS16, Subang Jaya. It is somewhere nearby the Subang Jaya
Komuter Station. In this project, the main contractor is KP Synergies Berhad – Transgrid
Ventures Sdn. Bhd. (Consortium), and the sub-contractor is Bintang Puspa. Once the
construction work is done, it will be passed over to TNB, even the contractors/employees are
restricted to enter the land, unless with permission.
The size of the land is roughly around 5 acres, 20234.3m2, and a combination of two lots.
It was then merged together for the construction of the TNB building. The purpose of the land is
to build the Subang Jaya Tower Center (Live Station), also known as ―Pencawang Masuk
Utama‖. It is a 2 years contract, estimated to complete on 20th October 2014 including the
engineering, construction & commissioning works. For your information, the total amount spend
is RM 130 million, and RM 17 million only on the construction and civil structure. Once the
building is completed, it will be around 5m high all the way to the roof of the tower.
Firstly, they clear off the site in order to make platforms for the piling machine to enter the
site. Piling must be done in flat ground. Then, they excavate vary from the size of the loading,
particular pile group thickness. Excavation level is depending on the size of the pile cap, the
depth/width/length of the pile cap = volume (m3). The higher the loadings, it requires bigger size
pile caps & deep excavation. As for smaller loadings, it only requires smaller size pile caps
&swallow excavation. Pile is around 300mm2 deep into the ground, using reinforced pre-cast
concrete piles 45mm thick.
Moreover, total numbers of 5 transformers is placed under the building with the depth of
1.5m. On the left side, it contains three 240 MVA (megavolt) transformers. And on the right side,
it contains two 90 MVA (megavolt) transformers. Each one of the transformer contains of 87
thousand liters of transformer oil. Furthermore, returning walls are built at the sides of the lower
ground; it is required to raise up the platform for the construction of walls, and then backfill it.
This project is a conventional construction; it does not use any system formwork or any
special plan off construction metrology. The only precast unit used is precast piles, because it is
cheaper as compared to in-situ casting.
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4. Objective
To help us get a more understanding on the basics of construction process while
paying a visit to the site.
Let us experience the actual working environment as a Quantity Surveyor on site
dealing with uncertain circumstances such as the weather condition and the risks
that may take place on the site.
Let us aware of the importance of personal safety on site, and the safety
precautions that we need to take in order to avoid accidents from happening. For
instance, we are required to wear safety helmet on site.
Increase our knowledge on the basic construction process by observing the
building team and gathering information on the actual practice that carried on the
site.
Explore and identify various types of building materials and type of technology
used in construction while constructing a building.
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5. Methodology of Scaffolding
Scaffolding is a structure or framework that is temporarily used to support loads of
humans and materials during a construction process. It is also used to ease the accessibility of a
person going from one floor to another and provides a safe working space at an elevated height.
Scaffolding system normally uses metal tubes or metal pipes to connect with each other and it
can also be from other materials besides metal. For example, bamboo, that is widely used in
Asia. Scaffolding is normally used when the working level is 1.5 m above the ground.
Structural elements of scaffolding
The basic elements of a scaffold are the three components such as: standards, ledgers
and transoms. The standards, also known as uprights, are the vertical long pipe or tube that
transfers the loading mass of the structure to the ground where they rest on a square base plate
for the spreading of the load. There is a shank in the centre of the base plate to hold the tube
and sometimes it is pinned to a sole board. In between each standard, the component that runs
horizontally is called ledger. It adds further support and weight distribution to the whole structure.
There is also a component called transom, which are placed upon the ledgers at right angles.
Main transoms are placed next to the standards and they hold the standards in place to provide
support for boards. Whereas intermediate transoms are placed in between the main transoms to
lend additional board support.
Besides standards, ledgers and transoms, there are a few other supportive elements that
are also used to reinforce the fundamental scaffolding. One of it is the braces. There are many
different types of braces such as the cross braces, façade braces, and additional couplers. It can
be used in different combinations to support the structure in several ways. Cross braces are
braces that run diagonally between ledgers and it is attach securely to standards to increase a
structure’s overall rigidity. However, they can also secure themselves to ledgers, in which case
they are simply called ledger braces. In order to prevent the structure from swaying, façade
braces are attached on the face of the scaffold. It runs the length of the face of the structure and
securely attaching at every level.
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6. Methodology of Scaffolding
Furthermore, couplers help in connecting structural elements, and come in several
variants. A right-angle coupler is used to connect a ledger or transom to a standard. A putlog or
single-coupler should be used if a transom supports a board and must be connected to a ledger.
A swivel coupler is recommended for any other angle of connection between scaffold piping.
The width, length, and height of each scaffold element depend on the need of the
building, but there are several required measurements for each basic component. Generally, the
width of a scaffold is determined by the width of the scaffolding boards. The height between
ledgers, which is also known as the lift height, is usually between 2 to 2.7 m. The placement of
transom depends on the board thickness. If the board is 38 mm thick, the transoms should be
1.2 meters apart, at the most. A 50 mm thick board requires that transoms be not more than 2.6
meters apart.
In addition to the basic structural elements of a scaffold, there are a few different kinds of
ties to secure a scaffold to the adjoining building. As a general rule, ties are attached at every 4
meters on alternating lift levels. However, depending on the kind of scaffold, the patterns and
types of ties used can also varies. For example, ties can be used to secure a scaffold to a
building by entering a building’s open window. A box ties are used to help in securing a scaffold
by attaching to a building’s external features, such as strong pillars.
Firstly, a level surface that is stable should be used to erect the, and if it is not, the
contractor will have to stabilize it and make sure that it is adequate to support the scaffolds.
Appropriate measures need to be taken if the scaffolding is to be erected in a public place as the
safety of bystanders is incredibly important. For example, the work can be scheduled to proceed
during quiet periods (usually at night), which less people are likely to be in proximity to the
structure or roads can be closed through council permission. An important reminder is that
scaffolding should never be erected near power lines as this can be extremely dangerous and
result in fatalities.
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8. Safety Precautions
Scaffolding can also be a dangerous place to work if it is not properly installed or used.
Your live might be at risk and also the people beneath might face fatal injuries if knocked by
falling objects from high level. A scaffold must always be erected plumb. This is because it will
be more stable for the workers while working on it. An OSHA-defined qualified person should
have knowledge about the bracing, load and safety code requirements for each and every job
site. A ―competent person‖ described by the COSHA should inspect all the elements of the
scaffolding to make sure in is in good condition before it is being used.
1. Ensure each and every worker is well trained.
As stated in the safety regulations code, workers are required to be trained in the design
structure and operation of scaffolding. The training should cover important safety work practices
such as how to safely get on and off the scaffold (using an access ladder, not the scaffold frame;
unless it is specially designed to be climbed and both hands are free to grab the rungs). Besides
that, it should also cover comprehensive fall protection training specific to the type of scaffolding,
dismantling and erecting procedures for those who will be involved.
2. Take time for the preparation work.
Before using scaffolding, we must make sure that the base is level, adjusted and sound no
matter how long it takes. The legs of the scaffolding must be plumb and all braces in place. Next,
make sure that the locking devices and ties are secured, cross members are levelled and the
planks, decks and guardrails are installed and secure. Last but not least, check the location for
ground conditions, such as slopes, and stay clear away from hazards such as overhead wires.
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9. Safety Precautions
3. Understand the load capacity.
Failure to consider the loads to which the scaffold may be subjected is one of the top things that
go wrong at the design stage. The scaffold must be strong enough and capable of holding the
desired weight, otherwise it could collapse. Do not try to fit as many workers as you can on the
platform just to speed up the construction process. Do not overload it with equipment and
materials that it is not supposed to and we are not supposed to rest anything near the guardrails
as they might just fall off.
4. Ensure the scaffold is properly secured.
The scaffold must be properly braced or tied to the building. It could be blown over if it isn’t well
secured. According to the Construction Safety Association of Manitoba, ―Bracing must be
properly secured in place; otherwise scaffold movement may dislodge an end, reducing the
stability of the scaffold. There is several braces retention or locking systems found on scaffolds.
These devices must operate freely for ease of assembling and dismantling, and also lock
securely to prevent a brace from dislodging. Nails and other miscellaneous odds and ends
should not be used in place of proper retention parts supplied by the manufacturer.‖
5. Use guardrails.
The design of the scaffold must incorporate guardrails on at least the three sides facing away
from the building if the scaffold is more than 10 feet above ground. There should be a top rail,
mid rail and bottom rail (toe board). If you must remove any guardrails while hoisting materials,
replace them promptly. Wear fall protection at all times, ex: Safety harness. People tend to
neglect the importance of guardrails as it might be an additional cost implied to the project.
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10. Safety Precautions
6. Inspect and maintain.
Scaffolding must be routinely inspected by the supervisor or by a competent person — ideally a
professional engineer or a person designated in writing by a professional engineer. In the case
of a suspended platform, inspect and test all components including welds, stirrups, connecting
pins, connecting plates, trusses, beams and working surface. Check whether the lumber is of
good quality and if any pieces get broken or damaged, replace them right away. Frames, braces
and other components must be inspected for damage, bends and excessive rust or wear. Also
check motors, platforms or wire ropes for damage from chemicals or corrosive material.
7. Use appropriate PPE (Personal Protective Equipment).
This includes non-slip protective footwear, head protection and fall protection as required, in the
form of a safety harness tied off to a solid structure, such as the building or on the scaffolding.
Ontario’s construction safety regulations indicate that the harness can be tied off to the
suspended platform or scaffold only ―if all or part of the platform or scaffold has more than one
independent means of support and the platform or scaffold is so designed, constructed and
maintained that the failure of one means of support will not cause the collapse of all or part of
the platform or scaffold.’
8. Good housekeeping.
There isn’t much room on a scaffold, so it’s important to store tools and materials in an orderly
fashion. Keep the platform free of obstructions. Place debris and waste material in a container or
remove it from the platform immediately.
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11. Safety Precautions
9. Keep your balance.
A scaffold and its platform must be perfectly level (CSA standard says it mustn’t deviate from the
vertical by more than 12 millimeters per three meters of height) to minimize the risk of workers
losing balance and falling off. Particularly on swing stages, there must be an adequately
weighted counterweight. Pay attention when working on a scaffold. Any sudden movements, or
reaching too far from the platform, can cause a loss of balance.
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12. Materials Used in Scaffolding
A scaffold, properly designed, erected and maintained will provide both a means of
access and working place which is as safe as those found in existing structures and on
permanent structures.
Basically the materials used in scaffolding are tubes,
couplers and boards. Tubes can be steel or aluminium,
although composite scaffolding uses filament wound tubes of
glass fibre in a nylon or polyester matrix. They are either in
'black' or galvanized. The tubes come in a variety of lengths
and a standard diameter of 48.3 mm. One basic 24 pounds
per unit a scaffold of many sizes and heights could be
assembled easily by a couple of labourers without the nuts or
bolts. The main difference between the two types of tubes is
the lighter weight of aluminium tubes, a greater flexibility and
lower strength. Tubes are generally bought in 6.3 m lengths and can be cut down to certain
typical sizes.
On the other hand, boards offer a safety working surface for scaffold users. They are
qualified wood and come in three thicknesses which are 38mm (usual), 50mm and 63mm. The
standard width is 225mm and the maximum length is 3.9m. The board ends are protected either
by metal plates called hoop irons or sometimes nail plates. (Google Book, n.d.)
The requirement of timber scaffold board is BS
2482. Steel, laminated boards or aluminium decking can
also be used. In addition to the boards for the working
platform, there are sole boards which are placed beneath
the scaffolding if the surface is soft.
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13. Materials Used in Scaffolding
Besides that, couplers are the fittings
which hold the tubes together. The most common
are called scaffold couplers. There are many
types of couplers of scaffolding and the three
basic types are right-angle couplers, putlog
couplers and swivel couplers. The coupler used
at construction in Malaysia is Swivel coupler
because Swivel coupler are highly flexible, have
exceptional performance, rotates in all directions
and it has international standard. The function of
the coupler is to connect horizontal and vertical
tubes together. Only right angle couplers and
swivel couplers can be used to fix tube in a 'load-bearing connection'. Single couplers are not
load-bearing couplers and have no load-bearing capacity.
Other types of common scaffolding
components include base plates, ladders, ropes,
anchor ties, and reveal ties, gin wheels, sheeting,
and many more. All elements in the scaffolding that
are made from metal can be painted. However,
elements that are made of wood should not be
painted as this could hide defects. Many scaffolds
measure tubes and boards in imperial units, with
tubes from 21 ft. down and boards from 13 ft. down,
despite the metric measurements given.
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14. Materials Used in Scaffolding
The construction site that we have visited is the Tenaga Nasional Berhad (TNB), located
atSelangor. The construction site uses steel scaffolding, swivel couplers and a piece of wood
placed on the scaffolding. We think the platform used in the construction is very dangerous
compared to the other countries. Basically in Malaysia, they are using the same type of platform,
a piece of wood, the reason why they used that type of platform is to lower the cost but it
increases the safety risks of the users on
the scaffolding.
In an international scope, like
Hong Kong, bamboo scaffolding is
commonly used, with nylon straps tied
into knots as couplers. In India, bamboo
or other wooden scaffolding is also
commonly used, with poles being
pounded together using ropes made from
coconut hair known as coir. (Unknown,
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15. n.d.)
Suitability of Usage
There are many different types of scaffoldings that are used in the construction industry
today. Each of them can also serve different purposes such as bricklaying, plastering, or
demolition. When deciding which types of scaffoldings should be used, the design, shape and
location of the building or structure should be considered. The most suitable or adaptable
scaffolding should be selected. Generally, there are 3 basic types of scaffoldings that are
supported, suspended, and aerial lifts.
The supported scaffolding is the most widely used scaffolding. It is set on the ground and
can be stacked up to very high altitudes. As the taller and wider the scaffolding gets, its stability
also increases. Workers can reach the upper platform by using the ladders at the side, or in
modern scaffoldings, through the stairs. There is also a similar type of supported scaffolding, but
with wheels installed at the bottom to allow movement and flexibility. However this type of
scaffolding is less safe than the common supported scaffolding as the stability is lower and it has
a limited height.
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16. Suitability of Usage
The suspended scaffolding however, is very different from the supported scaffolding. It is
suspended above the ground with special ropes which can support its required weight. It allows
workers to be able to do their job more conveniently due to its flexibility to move around the
building to the sides. It is much easier to install compared to the supported scaffolding but it has
higher risks. It cannot be placed too high on a building or structure as it can be dangerous.
There is also a cantilever type where there are no ropes to hold the scaffolding but instead is
supported with beams connected to the building or structure.
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17. Suitability of Usage
Aerial lifts are rarely used. They are considered to be vehicle-mounted aerial devices.
They are used only when some levels or location are harder to reach. Workers can ride on it and
be lifted up to the desired level or location.
Since scaffoldings are so widely used, the wide variety of scaffoldings can be brought
down to specific types. This means that they have different characteristics and serve different
purposes.
Birdcage scaffold is mainly used for carrying out ceiling works. It is normally constructed
inside the building from corners to corners to internal ceiling works.
Tower scaffold is very similar to mobile scaffolds. Mobile scaffolds have rollers attached
to them for movement. Tower scaffold has the same qualities but with additions of bracers that
are attached to the ground at the corners for better stability.
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18. Suitability of Usage
Tube and coupler scaffold is a system
that can have a connection of two tubes to be
placed at any position and is usually used on
structures with unusual design, shape or
function. The diameter and strength of the
components when using this type of scaffolding
should be considered. Tube and coupler
scaffold can be of metal, however, it is
important not to mix aluminium and steel tubes
in one scaffold.
Frame scaffolds are often minor scaffolds and
similar to the supported scaffoldings but with the use of
prefabricated frames, braces, and accessories. It does
not require a licensed scaffolder to construct or
dismantle. It is commonly used for bricklaying,
plastering, and painting.
Hung scaffold is similar to the suspended
scaffoldings. However, it does not have special ropes
to hold it, instead, it is an independent scaffold that
hangs from another structure which prevents its ability
to move around the building vertically or to the sides.
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19. Conclusion
After the site visit, we had gained experiences from the actual work environment on site.
We found that working on site is definitely not an easy job as the weather is usually hot. Even
after a few hours of site visit, we are so tired and exhausted. As a professional Quantity
Surveyor, sometime we haveto go on site to check out stuffs on our own. So, we have no choice
but to adapt such circumstances.
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20. References
1. WorkCover NSW (2011). Erecting, altering and dismantling scaffolding. Retrieved on
December 2nd, 2013 from
http://www.workcover.nsw.gov.au/formspublications/publications/Documents/erecting_alt
ering_dismantling_scaffold_part2_2826.pdf
2. Morra,M. (2011). 10 scaffold safety essentials. Retrieved on December 2nd, 2013 from
http://www.facebook.com/l.php?u=http%3A%2F%2Fwww.cosmag.com%2FPPE%2FPPE-Stories%2F10-scaffold-safety-essentials.html&h=AQH4UhCi
3. Google Book. (n.d.).Popular Mechanics (1954 February).Retrieved on November 30th,
2013,
fromhttp://books.google.com.my/books?id=Nt8DAAAAMBAJ&pg=PA103&dq=1954+Pop
ular+Mechanics&hl=en&sa=X&ei=sJAKTnTDMqRgQenq_mzAg&redir_esc=y#v=onepage&q&f=true
4. Unknown. (n.d.). Guidelines on the Design and Construction of Bamboo Scaffolds.
Retrieved on November 30th, 2013,
fromhttp://www.bd.gov.hk/english/documents/code/GDCBS.pdf
5. Safe Work Australia. (n.d.). Scaffolds and Scaffolding Work. Retrieved on December 4th,
2013 from http://www.safeworkaustralia.gov.au/sites/SWA/model-whs-laws/modelCOP/Documents/Draft-COP-December-2012/DRAFT-scaffolds-scaffolding-workCOP.pdf
6. Home Improvement Ideas, Tips and Guide. (2012). Different Types of Scaffolding and
Their Uses.Retrieved on December 4th, 2013 fromhttp://refresh-detroit.org/42/differenttypes-of-scaffolding-and-their-uses.html
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21. References
7. The University of Tennessee Office of Environmental Health & Safety. (n.d.). Scaffolding.
Retrieved on December 4th, 2013 fromhttp://web.utk.edu/~ehss/pdf/Scaffolding.pdf
8. Princeton University. (n.d.). Scaffolds and Aerial Lifts Requirements. Retrieved on
December 4th, 2013 from http://web.princeton.edu/sites/ehs/healthsafetyguide/B17.htm
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