The South African National Roads Agency (Sanral) has announced that the repairs to the sinkholes that formed on the R21 highway in February 2022 have reached an “advanced stage.”
Additionally, it said the rehabilitation of the R21 between Pomona and Olifantsfontein interchanges is “progressing well.”
This comes as the roads agency pledged a further R16.5 billion in projects for the 2024/2025 financial year in the provinces of Gauteng, Mpumalanga, Limpopo, and North West.
These initiatives comprise upgrades and repairs to the:
- R37 in Burgersfort
- N4 in Pretoria CBD
- N1 Musina Ring Road
- R504 in Wolmaransstad
- R510 towards Thabazimbi
- R573 Moloto Road Development Corridor
- N2 from Ermelo to the KwaZulu-Natal border
“These are exciting times for the industry, this investment means more opportunities for local businesses and jobs for our people,” said Progress Hlahla, Sanral Northern Regional Manager.
“These projects will have a significant impact on the socio-economic landscape of the country.”
R21 sinkholes
Sanral revealed earlier this year that the sinkholes on the R21 highway would cost in the region of R144 million to repair.
These hazards first appeared on the R21 near the Olifantsfontein interchange in Gauteng in February 2022, forcing the roads agency to close several lanes of the busy freeway ever since.
The lane closures and subsequent repairs have led to major traffic disruptions along the R21 for commuters to and from the OR Tambo airport and surrounding regions.
Like the many other sinkholes in the province, the cavities formed after heavy rains that dissolved the dolomite rock under the terrain’s surface, leading to large crevices that eventually caved in.
Roughly 25% of Gauteng land is affected by dolomite rock, and it presents an issue that necessitates extensive evaluations before any efforts can be taken to repair a sinkhole so as to avoid further collapses later on.
A specialist geotechnical engineering company, Jones & Wagener, was first appointed to investigate the sinkhole, which concluded that geophysical testing and extensive percussion drilling were needed to assess the area before plans for repairs could be drawn up.
Sanral’s northern region project manager, Oakley van Eyk, subsequently confirmed that a joint venture was formed with two construction companies – Raubex and Esor – and that work to address the sinkholes was started in December 2023.
R21 upgrade from Pomona Road Interchange to the Olifantsfontein Road Interchange
R21 upgrade
In November 2023, Sanral announced that it would rehabilitate 14km of the R21 highway from the Pomona Road Interchange to the Olifantsfontein Road Interchange to the tune of R309 million, with the project to stretch over approximately 24 months.
At the time the frequently travelled freeway was on its last legs, potholes, loose rocks, patches of missing tarmac, and long gashes in the road surface being common sightings.
The reconstruction efforts kicked off in early 2024 with Roadmac Surfacing carrying out the work under the supervision of KBK Engineers.
The R21 is labelled as a critical artery in the Gauteng road network, carrying a daily volume of over 45,000 vehicles in each direction, 11% of which are heavy vehicles such as trucks transporting goods.
The scope of work to be carried out on the R21 comprises the repair and maintenance of the road infrastructure as follows:
- Main Carriageway Fast Lanes – Surface repairs
- Main Carriageway Slow Lanes – Surface repairs
- Emergency Lanes and Inner Shoulders – Addressing defects with crack sealing and patching
- Resurfacing – New friction course over the full width of the carriageways
- Ramps and Cross Roads – Sealing cracks, patching localised failures, and new asphalt levelling course
- Bridge Decks – Mill and replace surfacing and installation of new asphaltic plug-type joints.
Sanral has placed priority on completing this upgrade in time, and has developed a comprehensive traffic accommodation plan for carefully managing lane closures and ensuring minimal impact during peak traffic hours, which includes a combination of daytime and nighttime work as well as short-term closures in off-peak periods, it said.
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