AfriSam’s specialised Roadstab cement is helping pave the way for a safer R67/5 road between Queenstown and Whittlesea in the Eastern Cape.
The contractor – the Raubex Construction and Roadmac Surfacing Cape Joint Venture (RBX / RMSC JV) project – will consume around 180,000 bags of AfriSam’s Roadstab cement for the stabilisation of the road’s G4 sub-base layer. The contract covers 18 km of roadway on the R67/5 route, from the Swart Kei River bridge in the south to Queenstown in the north.
A complete rehabilitation is underway which will see the road upgraded and widened. The road’s existing three metre per lane will be widened to 3,7 metre per lane, plus a 3 metre surfaced shoulder and rounding off on each side. Some vertical realignment is taking place, such as at those areas where drainage problems are addressed, where livestock crossings are required and at the new Swart Kei River bridge. This realignment will improve line of sight for motorists, allowing the authorities to raise the current 80 km/hr speed limit to 100 km/hr.
About 700 m3 per day of material is moved to level out the road, allowing the contractors to get on timeously to the layer works – the lower selected and upper selected layers. These comprise an imported G5 crushed gravel material of 300 mm, which is compacted to 95% of modified AASHTO density. This is followed by a 300 mm thick G4 sub-base layer which is stabilised with AfriSam’s Roadstab cement product.
The project’s stabilisation design requires a 3% portion of AfriSam Roadstab cement in the G4 sub-base. The 150 mm base layer is of G1 imported crushed stone, compacted to 88% of apparent relative density. The road is then completed with a surface of 20 mm Cape Seal with two slurries.
AfriSam ensures that the supply of road stabilising cement is ready and available when required, to support the scheduled roll-out of road construction activities. The Roadstab cement is trucked to site from AfriSam’s Queenstown depot, which is supplied by train line from the company’s Ulco factory in the Northern Cape. The nationwide footprint of AfriSam also allows it to service the project from its Bloemfontein depot, when necessary.
The road project also includes the building of a new bridge over the Swart Kei River and the widening of the Klaas Smuts River Bridge. The project began in July last year and completion is scheduled for April 2023.
