A novel pre-cast system has helped shave as much as six months off a reservoir construction programme in Katlehong, Gauteng.
The roof of the 35 mega-litre comprises more than 2 000 square metres of slabs, each up to 250 millimetres (mm) deep, supported by 16 columns and 18 beams, weighing a total of 12,3 tons and 7,5 tons, respectively.
The system was designed, manufactured and installed by Corestruc, complementing its already impressive portfolio of completed pre-cast concrete structures, ranging from public-sector infrastructure projects through to private property developments.
On this project, Corestruct worked closely with civil engineering contractors, Civcon and QC4 Civils, as well as consulting engineer, TLS Engineers & Project Managers, to deliver the project on behalf of Ekurhuleni Metropolitan Municipality.
QC4 Civils’ contracts manager, Ettiene Coetzee, says that this is the largest reinforced post-tensioned ground reservoir to be built by the company, as well as the first such structure to feature a pre-cast concrete roof.
Coetzee is extremely impressed with the system and service he received from Corestruc, noting that the professional team had allowed for 26 weeks to build the structure, however, this period could have easily been halved using the system.
“One of the biggest advantages is that it can be installed without the need to erect, dismantle and remove tons of supporting scaffolding, while the pre-cast system can be programmed concurrently with other activities and, therefore, does not restrict multiple activities on site,” he says.
Corestruc’s involvement in the project started right from the outset in its design stages, when every aspect of the system was finalised right down to the type of connection that would be used to build the roof.
This combined with an extensive system of pre-checks and post-checks at the company’s pre-cast facility, as well as rigorous planning before arriving on site, ensured yet another rapid installation by Corestruc’s team.
Installation commenced when up to 50% of the wall had been completed. An opening was left wide enough in the wall for the installers to access the structure, while the floor slab had already been poured and bases and plinths ready to receive the columns.
Testament to the company’s capabilities is the fact that tolerances of between about 20 mm were achieved at heights of 15 metres – the norm on all of Corestruc’s projects.
Each item is manufactured from 55 MPa concrete and therefore adds to the overall durability of the structure, while the clean and controlled construction environment promoted by this system is line with South Africa’s strict construction health and safety protocols.
Based on its impressive track-record on this project, it is not surprising that Corestruc has become synonymous with pressing water supply projects in the country as government forges ahead with plans to ensure this basic human right to all!