SCHOOL OF ARCHITECTURE, BUILDING AND DESIGN

BACHELOR OF QUANTITY SURVEYING (HONOURS)

AUGUST 2014

[BLD60104] CONSTRUCTION TECHNOLOGY l

Thun Shao Xun 0315919

Shane Sim Ee Han 0321288

Muhammad Hasif bin Alias 0316413

Hazim bin Abdul Aziz 0315773

Chin Tze Wei 0315767

Yee Algel 0315890

Lecturer: Miss Azrina Md Yaakob

MADGE MANSIONS

The building chosen for this assignment was a 3 blocks of 10 stories luxury condominium which consists of 52 units that includes 6 penthouses. The building is located at PT 26 Seksyen 89A, Bandar Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur.

The 3 blocks are categorized as Block A, Block B and Block C. Block A has 14 units with 2 penthouses while Block B and Block C has 16 units with 2 penthouses each. However, they do share similar designs and types of foundation, slabs and roof to each other.

For a high rise building, the foundation is pile foundation to support the building. The ground level and upper level uses suspended slabs to support loads. As for the roofing, flat roof is used which is shown on the model of the

building.

CONTENT

Introduction

Type of Foundation

Type of Slab

Type of Roof

Compare and Contrast

Foundation

Slab

Roof

Recommendation

Foundation

Slab

Roof

Thank You to Sales Manager for taking us a tour around the building

FOUNDATION

WHAT IS FOUNDATION?

Foundation is actually a base that supports the building by transferring their loads to layers of soil that have sufficient load bearing capacity and have settlement characteristics suitability.

DETERMINING THE TYPES OF FOUNDATION SYSTEM TO BE USED?

1. Types of soils and its load bearing

2. Types of building designs

3. Types of foundations that is suited to the relevant buildings

In addition foundation can be categorized into two types which are shallow foundation and deep foundation.

As for shallow foundation, it is recommendable for buildings where the loads imposed are low in relative to the bearing capacity of the soil. Examples of types of foundation that fall under this type are strip, raft and foot foundation.

Meanwhile for deep foundation, it is only applicable in which the bearing capacity of the soil is insufficient enough to support the load imposed. Therefore the loads are transferred to deeper layers having higher bearing capacity. Pile foundation is the common foundation that is used under this type of foundation.

So basically in the world of construction, there are a total of five foundations out there. The five types as listed below are:

•Strip

•Pad

•Pile

•Raft

•Trench

For every buildings it must not only need to take into account which of the total five types of foundations to use but also other considerations such as the nature of the load requiring support, ground conditions, the presence of water, accessibility, sensitivity to noise and vibration, proximity to other structures and project timeframes. So from the careful consideration of the choices, one can be able to make a definite judgement that will lead to favourable results.

In accordance to the research done on the type of foundation used for our desired site, Madge Mansion, we managed to conclude that the foundation used is piling. It is a group of long, slender, columnar elements that are typically made from steel or reinforced concrete and sometimes timber to support the superstructure. The pile cap will then connect the piles together & distributes the superstructure loads the layer beneath. This will formed part of the pile foundation.

Pile foundations are used principally to transfer the loads from a superstructure, through weak, compressible strata or water onto stronger, more compact, less compressible and stiffer soil or rock at depth. Basically this type of foundation is suitable for large structures and in situations where the surface soils at the proposed site are too weak or compressible to prevent excessive settlement.

There are three ways in which load can be transferred by pile to the ground. Technically there are:-

•End bearing pile

•Friction pile

•A combination of end bearing and friction pile

END BEARING PILE

These end bearing piles transfer their load on to a firm stratum that is located at a considerable depth below the base of the structure and they obtain most of their carrying capacity from the penetration resistance of the soil at the toe of the pile. Meanwhile the pile will behave as an ordinary column and should be designed in such a way. Even though the soil is weak, the pile will not fail by buckling and this effect is only considered if part of the pile is unsupported. Load is transmitted to the soil through friction or cohesion. But sometimes, the soil surrounding the pile may adhere to the surface of the pile and causes "Negative Skin Friction" on the pile. This inversely have a considerable effect on the capacity of the pile. Negative skin friction is caused by the drainage of the ground water and consolidation of the soil. The founding depth of the pile is influenced by the results of the site investigation and soil test.

FRICTION PILE

These types of pile also transfer their load to the ground through skin friction. The process of driving such piles does not compact the soil appreciably. These types of pile foundations are also known as floating pile foundations.

COMBINATION OF END BEARING AND FRICTION PILE

It is an extension of the end bearing pile where the bearing stratum is not hard, such as firm clay. The pile is driven deep enough into the lower material to develop adequate frictional resistance.

DIFFERENT TYPES OF PILE

Piles can be made of timber, concrete or steel. Timber can be used for the manufacturing of temporary piles and when the wood is available at an economical price. Concrete is used for the manufacture of pre-cast concrete piles, cast in place and pre-stressed concrete piles, while steel piles are used for permanent or temporary works.

ADVANTAGES

1. Piles can be precast to the required specifications.

2. Piles of any size, length and shape can be made in advance and used at the site. As a result, the progress of the work will be rapid.

3. A pile driven into granular soil compacts the adjacent soil mass and as a result the bearing capacity of the pile is increased.

4. The work is neat and clean. The supervision of work at the site can be reduced to a minimum. The storage space required is very much less.

5. Driven piles may conveniently be used in places where it is advisable not to drill holes for fear of meeting ground water under pressure.

6. Driven piles are the most favoured for works over water such as piles in wharf structures or jetties.

To summarize it all, there a few definite reasons as mentioned above as to why our chosen site, Madge Mansion is using pile foundation rather than others. Firstly Madge Mansion is a multi-storey building that carried heavy loads that need to be transmitted to the soil. Secondly pile foundation is useful for surface soil that are weak and compressible. So that it can support the heavy load of the building transmitted to the soil. Therefore through the explanation of each reason it shows that this type of foundation is more suited to this building as it provides a solid base for the building.

REFERENCES

1.Pile Foundations. [ONLINE] Available at: http://www.designingbuildings.co.uk/wiki/Pile_foundations. [Last Accessed 15 Nov 2014].

Driven Piles: Advantages and disadvantages. [ONLINE] Available at: http://www.abuildersengineer.com/2012/11/driven-piles-advantages-and.html. [Last Accessed 15 Nov 2014].

SLAB

Slab is one of the most important element in the building. Slab is a flat layer of concrete that serves as a walking surface but may also serve as a load bearing member, as in slab homes and is commonly known as floor

FUNCTION OF THE SLAB

1.Provide a flat surface2.To support load3.Sound, heat and fire insulator4.Act as a divider (privacy) for the occupants5.Upper slab became the ceiling for the storey below6.Space between slab and ceiling can be used to place building facilities

TYPE OF SLAB

Concrete slab is a common element that has been used in modern buildings. In numerous local and modern structures a thick solid piece, upheld on establishments or specifically on the subsoil, is utilized to build the ground slab of a building. These can either be ground-bearing or suspended slab. There are two types of design for the floor slabs which are precast and in-situ concrete

Precast Concrete

Precast concrete offers an almost endless variety of products and design options for both above-ground and underground construction. From the largest infrastructure projects to the smallest architectural details, precast is one of the most versatile and sustainable building materials available for today’s fast-paced, environmentally conscious construction.

Advantages of precast concrete

1.The concrete of superior quality is produced as it is possible to have better technical control

on the production of concrete in factory.

2.It is not necessary to provide joints in the precast construction.

3.The labour required in the manufacturing process of the precast units can easily be trained.

4.The moulds employed for preparing the precast units are of steel with exact dimension in all

directions. These moulds are more durable and they can be used several times.

5.The precast can be moulded into desired shape and finish with accuracy and smooth surface.

6.The precast structures can be reusable.

7.The transport and storage of various components of concrete for cast in situ work are

eliminated when precast members are adopted.

8.By using precast concrete the building will complete in a shorter time

9.When precast structures are to be installed, it is evident that the amount of scaffolding and

formwork is considerably reduced.

In-situ Concrete

DEFINITION

An in situ concrete suspended floor is one constructed with reinforced concrete and designed to carry its own weight and any imposed a loading, spanning between supporting members in a structure. Supports for floors are typically beams, columns or walls.

Advantages:

1.It grasps different building shapes

2. It can be assumed to be more or less monolithic

3. Connections are homogenous with the rest of the frame

4. It is easily used for both way structural systems

5. It is not necessary to pay for crane on site

6. Construction can continue eventhough the weather conditions is bad.

7. Better working conditions for the building operatives

ANALYSIS

Suspended slab

After we have visited the site, Madge Mansions, the type of slab that is benefitable for the 10

storey is suspended slab. The suspended slab is actually the floor slab with at least 2 of its opposite edges supported by the wall. The floor compasses in the middle of backings and will typically be redirected under burden to a measurement that is constrained by the configuration utilized.

Suspended slabs are slabs that are located above the ground. They are usually used to create floors for the upper storeys of the houses, but can also be laid on top of the pre-constructed walls to create the ground floor. Suspended slabs are basically made of concrete and steel mesh, the same can also be say for ground slab. They are normally pre-fabricated offsite, and transported away by truck. Meanwhile some of the slabs have hollow channels running through them where these 'hollow core slabs' are used to help reduce weight, and also to allow cabling and piping to be run through it. In addition the suspended slabs have to be pre constructed and lifted into it desired part by a crane. Once it is in place, the edges are then grouted for waterproofing and after a few more days, more concrete is then poured on top to act as a cap. These are typically used in multi-storey dwellings for upper floors, but can also be put to good effect on the ground level in hilly terrain. By digging out a site, only then can concrete support walls be erected to bring the slab height to ground level.

Advantages

• Can be used where other slabs are deemed in suitable - for example, on a steeply sloping terrain.

• Allows easily access to under-floor areas.

• Relatively easy to install once the supports and machinery are in place.

• More effective than bearer / joist sub-floors in blocking out noise pollution from upper floors.

Disadvantages

• Requires the suitability of crane

• Not as well insulated as a ground slab, as the base are not touching the ground

REFERENCE

Reinforcement For Slabs on Ground. (n.d.). Retrieved November 11, 2014, from

http://www.concreteconstruction.net/concrete-construction/reinforcement-for-slabs-on-

ground.aspx

(n.d.). Retrieved November 17, 2014, from http://www.concrete.org.uk/fingertips_nuggets.asp?

cmd=display&id=245

In situ concrete (building material). (n.d.). Retrieved November 17, 2014, from

http://global.britannica.com/EBchecked/topic/284418/in-situ-concrete

Roof Type of The Building

A roof is a structure that covers the above part of a house or a building with one of the

most obvious purpose is to shelter from rain, sunlight, heat and any other things that

would hit the top part of a building. It is supported by another type of structure, which is

called the beam. There are many types of roofs out there in the construction industry. To

name them one by one, there are the flat roof, gable roof, mansard roof, shed roof, and

also the pitched roof. But for this building our group have chosen, this specific

construction industry decided to use the flat roof instead of any other. The reason why

they chose this type of roof is precisely because they wanted to make a space on the

rooftop where residents can pull up activities.

If you look closely in the picture above, only some of the roof is protected with railings.

Since this building is located near the KLCC Twin Towers, residents of this 9madge

apartments have the advantage to observe fireworks from the rooftop where the

authorities of the Twin Towers will usually pull up on certain occasions. The type of

material they use for the roof is most probably Reinforced Concrete (RC) like most of

any other apartments with flat roof would have.

As we all know, flat roofs are not parallel to the ground due to avoid water from flooding

the roof. So the flat roof of this particular building is a bit slanted to a certain degree

angle (mostly between 10-15 degrees). On rainy weathers, the rainwater collected on

the roof will be directed to the hopper similar to the pictures below and the water will be

disposed to the ground via the down pipe.

References

http://www.ultraframe-

conservatories.co.uk/image/installation/orangery_installation_025.jpg

http://www.1stassociated.co.uk/roof-problems-valley-gutters.asp

Foundation

Besides pile foundation, there are also another 4 types of foundation, which are:

4. Pad foundation

5. Strip foundation

6. Trench foundation

7. Raft foundation

Every foundation has different advantages and disadvantages. However, all of these foundations all served the same purpose which is to support the building and loads. There are a few conditions that could affect the type of foundation system to be used for the building which are type of soil, type of building, and the condition of the site.

Pad foundation

Pad foundation is a shallow type of foundation which is not more than 3m deep. Moreover, it is the most economical type of foundation as the amount of the concrete needed is less than in any other types of foundation. Pad foundation only required an excavated pit in order to construct it, unlike strip, trench and raft foundation. All the pad foundations are separated to support every each different part of the building.

Pad foundation have a weakness against uplift force, strong wind, and earthquake. It also unsuitable to be used on site with poor ground condition due to its separated arrangement in a building.

The load is supported by the piers and columns. One of the advantages of pad foundation is its efficiency to support most types of building having low loads. On the other hands, the size of the pad foundation can be manipulated to accommodate the design of the building and the ground condition. The thickness of the slab can be reduced by adding reinforcement bar into the concrete slabs

which will provide even greater supportive strength to the foundation.

Strip Foundation

Strip foundation is also regarded as another type of shallow foundation. Strip foundation is placed under the load bearing wall which provide a longitudinal support to the building. The load is then transfer from the load bearing wall to the concrete strip that have been laid on earth. Therefore, a trench is required to be excavated on the site while constructing the strip foundation. One of the reason as to why strip foundation is being widely used in normal building is due to its economic cost.

However, strip foundation consists of a few disadvantages such as requirement of workmanship in brick laying under the ground level is more difficult than in any other type of foundation. In addition, it is also limited to the design or the type of building. Strip foundation is only usable to support a building that is up to 3 stories high or buildings having light load. On the other hand, it is also inadequate to support structure that has too complicated design on it. Moreover it is also not suitable to be used on soft soil like gravel or sand.

Figure 1 Retrived from http://www.gare.co.uk/images/foundation1.jpg

Trench Foundation

Trench foundation is a similar type of foundation to strip foundation. Nevertheless, there is one particular difference between strip and trench foundation which is the thickness of the concrete strip in the foundation. Trench foundation usually have a thicker concrete strip than strip foundation. . As a result of this, it has a greater bearing capacity compare to strip foundation.

Thus, it brings more benefits than the strip foundation such as require less man hours, higher strength and need less skill trades

Raft Foundation

Raft foundation or a mat foundation is an alternative shallow foundation. It is a foundation that covers the whole area under the building with a thick reinforced concrete slab which is like a raft that is carrying loads on water. The area of raft foundation could be the same as the area of the building or even larger than it.

It is suitable to be used on an area with soft ground. The load which is supported by the foundation is equally transfer to the ground. It can resist irregular settlement on different parts of the building.

Due to the constructing area being large, it is also the most expensive foundation among the 3 types of foundations as stated above.

Figure 2Retrieved from Chudley, R., & Greeno, R. (2010). Building construction handbook (8th ed.)

Conclusion

As a conclusion, these 4 types of foundations all are shallow foundation which can only withstand a building that is not more than 4 stories high and with a low load. Madge Mansion is a high-end condominium that is 5 stories high and is not suitable to use any of the provided foundations as stated above. We have concluded that it is for the best not to propose any of the above mentioned foundation for the building. Therefore, pile foundation is the best and most suitable foundation to be used in such building although the construction cost is more costly than the rest.

References

Chudley, R., & Greeno, R. (2011). Construction technology (5th ed.). Harlow, England: Pearson Prentice Hall.

Foster, T. (2013). Brown Field Site and Suitable Foundation Types. Retrieved November 9, 2014, from http://www.jwlowry.co.uk/wp-content/uploads/Brown-Field-Site-and-Suitable-Foundation-Types.pdf

Recommendation

To improve the suspended slab as seen in Madge Mansions, the suspended should be added reinforcement. Reinforcement for slab can be either steel bar reinforcement or mesh fabric reinforcement (BRC).

Steel bar reinforcement for suspended slab

Mesh Fabric Reinforcement (BRC)

Mesh fabric reinforcement is more widely used because each sheet is precast and does not require specific skill to install. It comes with standard sizes as below:

Suspended slab is reinforced in order to support heavy loads such as dead loads and superimposed loads. Steel bars increases the compressive strength of the slab and spreads the pressure evenly across the slab. It also ensures the slab is able to withstand future renovation or modification.

Compare and Contrast

ROOF

Flat Roof Pitched Roof

Maintenance Require lesser maintenance throughout life of roof.

Require constant

maintenance throughout life of roof.

Resistance to weathering Better resistance due to sloping and use of slate and

tiles.

Lower resistance due to poor

sloping

Space Extra space or room between roof rafters and ceiling joists.

Outdoor surface with flat surface on top of

rafter.

Aesthetic Flat base only roof structure with modern appearance.

Two-sided sloped roof with varies design with traditional

appearance.