Solving the dilemma of housing shortage with precast
City Deep Green project is an excellent example of the benefits of utilizing precast concrete for the construction of social housing. The kick off for the project was the dire need for affordable housing in City Deep, Johannesburg, South Africa. Straight from the start, it was clear that the project had to follow a tough schedule, which is why hollow-core slabs were chosen for the project. Hollow-core slabs are much faster to erect compared to the traditional cast-in-situ concrete floor slabs, which makes them ideal for projects, where the deadlines are tight.
The project consisted of 328 housing units, which were constructed in several phases. The units are four-storey walk-up blocks, which include one and two-bedroom homes with basic finishes. Raft foundations were used for the building due to the bearing capacity of the soil underneath. It was followed by structural brickwork, after which the hollow-core slabs were installed on three levels. The structures were topped by IBR roof sheeting.
The concrete elements for the City Deep Green project were manufactured by ESA, one of the leading precast manufacturers in South Africa and a long-term Elematic customer. They won the price competition, but they were also known for their ability to produce high quality concrete elements in the set timeframe. For the specific project, they delivered 10,000 m² of hollow-core slabs. According to Craig Webber, CEO of ESA, after manufacturing the elements, their installation teams transported the slabs to the site and installed them. ‘’Slab soffits are neat and the v-joints fit together without gaps, resulting in a good quality, aesthetically pleasing finish ‘’ says John Whiteman of Motheo Construction Group.
In 2014, The City Deep development was awarded the Southern African Housing Foundation (SAHF) award in recognition of the SAHF Best Social Housing Project of the year.
City Deep Green in detail:
- Location: Johannesburg, South Africa
- Year of construction: 2015
- Size: 328 housing units
- Developer: Joshco (Johannesburg Social Housing Company Soc Ltd)
- Main contractor: The Motheo Construction Group
- Precaster: ESA (Elematic SA (Pty) Ltd)
- Amount of precast elements: 10,000 m² of hollow-core slabs