Cutting-edge Spraylock Concrete Protection technology was successfully deployed to enhance the repair of concrete bridges on the N14 highway.
The technology was specified for this application by Bogonala Consulting Engineers which completed the repair design and later supervised the works programme on behalf of the Gauteng Department of Roads and Transport.
DSC-Zendon was appointed by principal contractor, Power Construction, to undertake the repairs to the bridge. The appointment was based on the company’s impressive track record of providing high quality bridge repair services. As one of the foremost concrete repair specialists in the country, DSC-Zendon is also an approved applicator of Spraylock Concrete Protection’s technology.
“The work scope included raising the existing concrete bridge parapets to an acceptable standard and then installing new precast-concrete handrailing. Old and new concrete was then prepared using a high-pressure spray, before being treated with Spraylock Concrete Protection’s technology to provide permanent protection. An overcoat was applied afterwards to complete the repair works,” Lourens Pieters, Managing Member of DSC-Zendon, says.
Spraylock Concrete Protection’s technology was applied over 700m2. It penetrates into the capillaries and pores of low permeability reinforced concrete to condition the construction material and improve pH levels to help protect embedded reinforcing steel. By significantly improving the durability of concrete, Spraylock Concrete Protection’s technology reduces maintenance requirements, saving client bodies money and time.
Carl White, Managing Director of Spraylock Africa, says that Spraylock Concrete Protection’s technology was specified for this project because it enhances concrete remediation practices. “Our technology forms a longer calcium-silicate-hydrate chain within the concrete capillaries and pores to waterproof concrete. Tests have demonstrated that concrete treated with our technology is able to withstand 100m of Head Pressure. Moreover, it purges or encapsulates contaminants with the concrete capillary and pore structure, effectively removing their contribution to reinforced concrete distress,” White says.
Concrete durability issues that are successfully addressed by the technology include de-icing chemicals and freeze-thaw damage, moisture migration and alkali-aggregate reactivity. This is in addition to concrete contamination, permeability, moisture migration and carbonation, while Spraylock Concrete Protection’s technology also locks in free alkali to mitigate efflorescence.
Pieters says that a further advantage of the technology is that it can be applied quickly and concrete surfaces can receive coatings or coverings 24 hours after being treated, making it ideally suited to fast-track projects.
White says that he is proud of Spraylock Africa’s participation in yet another successful bridge repair project that was undertaken by DSC-Zendon. “We have nurtured a close working relationship with the company over the years and are looking forward to building on this by providing a world class solution that enhances the company’s concrete repair operations,” White concludes.
