Sika Repairs Strand High School Stadium

Sika’s high performance products were recently first choice for a revamp project of the sports stadium at Strand High School in Cape Town. One of the conditions specified by the school was that the stadium should be able to withstand not only scholar and spectator traffic, but also the wear and tear caused by rugby and soccer boots.

Upon inspection of the concrete stands, Lock Gous of Rolo Verwe paint contractors soon realised that the cracked and chipped concrete required more than just a paint job, if it was to have an effective renovation. After consultation with Sika, SikaLatex, Sikaflex-11 FC+ i-cure and Sika Primer-3N were specified for the repairs. Once Strand High School had agreed to the Sika rehabilitation, the project was underway and Sika gave on-site training to five Rolo Verwe staff members.

SikaLatex was used as a mortar improver, in the mortar mix, as well as a bonding agent on all the areas that needed to be repaired. As the bonding agent SikaLatex was mixed with water and cement and brushed onto the prepared surface. While it was drying (tacky to touch), the mortar mix containing SikaLatex was applied to fix the damaged edges of the concrete stands. When used as an additive, SikaLatex, a high quality, synthetic polymer emulsion, substantially increases the physical qualities of cement mortars; it provides increased adhesion strengths, reduced shrinkage, greater elasticity and excellent water resistance. SikaLatex also provides increased abrasion resistance. The Latex/cement slurry was brushed onto the concrete surfaces as a bonding agent and was used as an additive in the mortar mix for repairing the chipped edges.

Once the expansion joints were prepared with a grinder, and loose particles and dust removed, backing cord was placed into the expansion joints to regulate the depth of seal and provide a solid backing onto which the sealant is placed and tooled. The sides of the joints were then primed with Sika Primer-3N, a one-component, epoxy-polyurethane, solvent-based primer designed for porous substrates.

The prepared expansion joints were subsequently filled with Sikaflex-11 FC (grey), a one-component, elastic joint sealant and multi-purpose adhesive. Solvent-free and odourless with very low emission, Sikaflex-11 FC provides bubble-free curing, good mechanical resistance as well as weather and ageing resistance. A weak dilution of soapy water was then used to break the surface tension of the sealant during the tooling process, as well as to smooth the sealant and create an even surface.

After a three-day curing period, the stadium was coated with good quality paint. As a very successful Sika project, Strand High School can rest assured that its stadium will withstand many years of robust sporting events.