Concrete Work

 

Precast Concrete Elements

 

Precast concrete element systems can be used for floor slabs, facades, external elements such as bay windows, staircases and internal partition walls. Take a facade for an example. The mould is carefully engineered to the required profile and dimensions and is made of steel instead of timber. Unlike timber formwork, it can be reused very many times with minimal distortion or damage. Locations for boxing-out, conduits, window frames and reinforcement are precisely marked and fixed into position. Once all the preceding operations are completed and inspected, the concrete is poured, compacted and finished, and the curing of concrete proceeds in a controlled environment. At a predetermined time after casting the facade will be demoulded and set aside mechanically for subsequent dressing of the unit such as with tiling.

 

       

 

Precast facade

 

Precast staircase

 
 

As the facade is cast to the designed profile and dimensions the layout of tiles can be planned in such a way that only minimal cutting of tiles is required. Tiling can be carried out at ground level in the prefabrication yard where a safe and comfortable working environment prevails. For tiling in-situ, the workers otherwise need to work outdoors on bamboo scaffolding hanging at high levels. Good quality of tiling work can be much better provided and maintained by a small group of experienced and skillful plasterers under factory conditions where properly run quality assurance procedures can also be more easily applied.

 

Prefabrication yard on site

 

Upon delivery to the site, the precast facade will be lifted by crane to the designed position, secured with temporary bracing and fixed into position by non-shrinkage grout. Part of the concrete slab adjacent to the facade is left unbuilt until the facade is fixed in position after which this part is concreted to form a homogenous tie between horizontal and vertical planes.

 

Transfer of prefabricated facade to the working level

 

Precast elements may be made in a casting yard on site. It is believed that precast concrete construction is about 25% more productive than the conventional method of construction. Additionally, because of mass production, the materials can be better utilized and wastage can be kept to a minimum. The use of formwork can also be reduced by the use of precast concrete units.

 

The precast facade is secured with temporary bracing

 

However, there are some limitations in using precast concrete. If precast units are only small in quantity, the construction cost will be high. In addition, storage and transportation of precast units can also be a problem for construction sites located in congested urban areas.

 
Example Application of Precast Facade
 
Cheung Sha Wan West Phase-II, Hong Kong
 
Sau Mau Ping Estate Redevelopment Phase-V, Hong Kong
 
Shek Yam Estate Phase-III, Hong Kong
 
Tseung Kwan O Area 73A Phase-II, Hong Kong
 
Tseung Kwan O Area 74 Phase-IV, Hong Kong
 
Example Application of Precast Staircase
 
Cheung Sha Wan West Phase-II, Hong Kong
 
Residential Development at Aldrich Bay Reclamation, Shau Kei Wan, Hong Kong
 
Sau Mau Ping Estate Redevelopment Phase-V, Hong Kong
 
Shek Yam Estate Phase-III, Hong Kong
 
Tseung Kwan O Area 73A Phase-II, Hong Kong
 
Tseung Kwan O Area 74 Phase-IV, Hong Kong
 
Example Suppliers for Precast Concrete Facade/Staircase
 
China State Construction
Engineering Corporation
76 Hong Gang Road, Luo Hu
District, Shenzhen, P.R.C.
Tel: 2823 7888
Fax: 2865 5939
 
Shen Zhen Sun Wah
Concrete Products Company Limited
Niu Shing Village, Nam Shan
District, Shenzhen, P.R.C.
Tel: 2893 4648
Fax: 2494 7251
Golden Trend Construction Limited
Bai Sha Shui Village, Long Xi,
Long Gang District, Shenzhen,
P.R.C.
Tel: 2380 9605
Fax:2414 5766
 
Sun Fook Kong Construction
(Concrete Products) Limited
Shu Gang Road, Shekou
District, Shenzhen, Guangdong, PRC
Tel: 2828 1688
Fax: 2827 6275
Lamma Rock Products Limited
Architectural Member
Engineering Company Building,
Huang Qi Town, Nanhai,
Guangdong Province, P.R.C.
Tel: 2398 4018
Fax: 2789 1040
 
Unicon Concrete Products
(Hong Kong) Limited
D.D. 95, Lot No. 9-12, Ho
Sheung Heung, Sheung Shui,
N.T., Hong Kong
Tel: 2477 0867
Fax: 2478 6220
Main Kind Industrial Limited
Xiangyuan Village, Longgang
Pingdi Town, Shenzhen,
Guangdong, P.R.C.
Tel: 2336 1262
Fax: 2336 1077
 
Unicon Concrete Products
(Hong Kong) Limited
Heng Li, Dongguan, 
P.R.C.
Tel: 2477 0867
Fax: 2478 6220
Orientfunds Precast Limited
Fu Lu Sha Region, Sha Tian
Town, Dongguan, Guangdong,
P.R.C.
Tel: 2546 2612
Fax: 2517 0873
 
Wai Hing Construction
Materials Company Limited
West Nan Gang Road, Nan
Gang, Huang Pu, Guangzhou, P.R.C.
Tel: 2715 6942
Fax: 2713 0762
Redland Precast Concrete
Products Limited
Little Montana Island, 
Zhuhai,
P.R.C.
Yau Lee Wah Concrete
Precast Products Company Limited
Qinghu Industrial District,
Heping East Road, Longhua Town, Baoan Qu, Shenzhen, Guangdong, P.R.C.
Tel: 2753 4388
Fax: 2753 4300
 
 

Low-Waste Buildings Technologies & Practices
Home