Construction World October 2017

HOUSES for the PEOPLE Residential units are going up apace in the Clayville Ext 45 area near Tembisa – between Pretoria and Ekurhuleni – as Raubex Building con- structs houses for private sale as well as RDP flats, each with a solid raft foundation of AfriSam readymix concrete.

The developments, by well-known developer Valumax, include bonded standalone houses for private sale and government-funded blocks of RDP flats. Work has just been completed on 822 private residential houses in a project that began in early 2015, where AfriSam’s readymix concrete was required for the ‘waffle raft’ foundations under each unit. Between eight and nine cubic metres of concrete was poured per house, depending on the floor space, which are 45, 52 or 56 square metres in dimension, according to Raubex Building quantity surveyor, Renier Rossouw. For this project, AfriSam delivered about 36 m 3 of concrete a day, amounting over the full project duration to about 7 000 m 3 , says AfriSam sales manager Adele Wentzel. This was sourced from the company’s Olifantsfontein plant, just 11 kilometres from site, allowing cost and logistical benefits. Raubex Building also recently completed the first phase of a government-funded project for RDP flats, in close proximity to the private housing development. “In February, we handed over 11 three storey blocks, comprising a total of 237 flats with a 40 m 2 footprint each, to the client,” says Rossouw. “Here, we contracted AfriSam to provide readymix both for the raft foundations – which used 1 100 m 3 of 20 MPa strength concrete – and for the rib and block slabs between the flats, which consumed about 500 cubic metres of the stronger, 25 MPa concrete.”

A second phase of RDP flats is now underway, also with readymix supplied by AfriSam, and is scheduled for completion by Raubex Building in March 2018. This larger contract is for 484 living units in 18 four storey blocks, with each block comprising 20, 28, 32 or 36 units. Wentzel says: “By the end of this phase, AfriSam will have delivered 1 800 m 3 of readymix concrete for the raft foundations of these blocks, as well as another 1 200 m 3 for the rib and block slabs.” Due to the highly structured planning of the work cycle on these contracts, a reliable supply of readymix is vital, emphasises Rossouw. For this reason, he says, AfriSam’s capacity as a large supplier is important so that supply can be re-routed from its other operations if anything affects production at one plant. “As a contractor, you are constrained by budget and time, so we need partners that deliver as promised,” he says. “We have built a good working relationship with AfriSam over the past four years or so, and have always been impressed by their reliability, as well as the quality of their product. AfriSam is also able to ensure the necessary quality requirements, as each pour must be tested independently in terms of company policy and contract requirements.” The depth of expertise in cement and concrete technology also allows AfriSam to offer support to customers in regard to testing and quality issues, according to Wentzel. The company can even train

Raubex Building's Renier Rossouw with some of the local labour used to create job creation and skills development during the project. customers’ employees on the various procedures to be followed for testing on-site. She also highlights the importance of good systems and constant communication on both sides of this partnership, ensuring that each party knows what to expect. Rossouw says Raubex Building appreciates the quick response from AfriSam’s control centre, which monitors readymix trucks and responds to customer queries. On the site itself, there are about 260 workers in this phase, mostly local people who are engaged and trained by Raubex Building. The construction methods are deliberately labour intensive, to allow a high level of job creation and skills development. For example, the AfriSam readymix for the raft foundations is moved on site mainly with the use of wheelbarrows, while manually operated power floats are used to achieve the necessary smooth surface. Local subcontractors are engaged to provide electrical installations in each

residential unit, as well as to install plumbing, glazing and ceilings. 

Raubex Building recently completed the first phase of a government- funded project for RDP flats in Clayville Ext 45.

AfriSam’s readymix concrete was required for the ‘waffle raft’ foundations on the private residential houses.

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CONSTRUCTION WORLD OCTOBER 2017