When the floor of Unilever s newly built 25,000m² premises in River Horse Valley in Durban needed strengthening in a hurry, the project engineers turned to Sika, leading supplier of flooring materials to the construction industry. Major cracks had appeared in the concrete slab of the building, which was in a poor condition but could not be re-poured. The project engineers, Sutherland Associates, specified Sika CarboDur Plates as the solution. The architects were Elphick Proome Architects and the contractor, Sealcon Systems.

The job at hand was to strengthen the slab, to brace around the concrete pillars, and to ensure the slab was suitably strong as the flooring had to be fit for heavy machinery. Also, it needed to act as external reinforcement once bonded. However, the task was met with a major design challenge: the engineers specified S812/120 strips but the delivery time would take two weeks and the client could not afford the delay. This meant that the engineers would have to re-design it using S512/80 strips, which were ex-stock. They had just two weeks to complete the work, starting 7 December 2010.

Sika supplied CarboDur S512 x 520m, Sikadur-30 (x 40 6kg kits), Sikadur- 31CF (x 8 15lt kits) and Colma Cleaner (x 5). For this particular purpose, Sikadur-31 CF did not need a primer thus it saved time, as well as provided high strength adhesion, high initial and ultimate mechanical strength, and good chemical resistance. Sikadur-30 adhesive was applied to the cleaned CarboDur strip, and was then applied to the prepared substrate to form a thin layer. The CarboDur plate was applied to the concrete surface and a rubber roller was used to ensure the strip was pressed into the adhesive until the material was forced out either side. To prepare the surface, substrate was grit blasted to ensure the substrate was clean and free from laitance, grease, oils and coatings. Once a good, open surface was achieved, the substrate was repaired and leveled using Sikadur-31CF. The strips were then wiped clean with Colma Cleaner and allowed to flash off.

With the expertise of a local engineer who was on site to supervise the preparation and application, the re-design went smoothly and was completed on time. The applicator was Sika trained, so there were no last-minute crises. Despite the tight turnaround time, the job was successfully delivered, guaranteed by Sika s reliability.