The Cement & Concrete Institute (C&CI) drove a campaign through a special task group to promote the concept of prefabricated construction that is underused in South Africa.
The C&CI’s Precast Concrete Task Group, in collaboration with the University of Cape Town, arranged technical workshops pertaining to the design principles of precast concrete structures in Cape Town, Durban and Johannesburg.
The campaign entailed holding workshops to promote the concept of design principles for precast concrete structures and C&CI structural engineer Gary Theodosiou says that construction with prefabricated structural elements offers several advantages, including the speed of construction by reducing propping time for in situ cast concrete; improved quality, owing to prefabrication’s controlled production conditions; and enforced coordination and teamwork because constructability, layout and connection details have to be planned well in advance.
Theodosiou believes precast concrete contractors are not marketing their products and expertise sufficiently to structural engineers who consequently miss out on the design opportunities offered by precast concrete ele- ments, particularly columns, beams, and stairs.
“Ultimately, the client loses out on the best possible solution for the project,” he says.
Further, Theodosiou claims that precast concrete can offer improved production lead times, compared with structural steel and conventional on-site reinforced concrete construction. Concrete structures offer more flexibility in the methods used to construct them.
“Concrete has an advantage over other materials – concrete elements, such as walls, columns, beams, trusses and slabs, can be constructed in situ on site or precast on site and lifted into their final position, for example, with tilt up and stack casting. “Concrete can also be precast in a yard and transported to site and erected into position,” he explains.
He says precast concrete construction deals with all the important requirements for sustainable concrete structures, including durability, quality, speed of construction, appropriate finishes and cost effectiveness.
By producing precast concrete in a controlled environment, it is possible to monitor all stages of production, including adequate curing, compaction and the quality and depth of cover concrete, as well as ensuring that products fully comply with strength requirements.