Sika’s world-class products were specified by general contractor, Chartel, for repairs to the four-year-old NG Kerk in Jeffrey’s Bay. Although only laid two years previously, the floor slabs in the church had sagged by 50mm in the centre and were displaying extensive cracks. Further cracking was evident in the walls. Rehabilitation of the roof was also required which included cutting back of the concrete and grinding the substrate of the interior ceiling. The contractor was confident that Sika’s internationally approved CarboDur Plates were the ideal solution for this project, and authorised staff training on application of the product before commencing the job.
Sika CarboDur Plates are pultruded carbon fibre reinforced polymer (CFRP) laminates that are specifically designed for strengthening concrete, timber or masonry structures, and are bonded onto the structure as external reinforcement using a specific Sika adhesive depending on the temperature ranges. Besides increasing load capacity of floor slabs, beams and bridges, Sika CarboDur Plates can be used to repair structural damage caused by fire or even earthquakes. They are non-corrosive, lightweight and very easy to install, and they provide very high strength, excellent durability and outstanding fatigue resistance. Easily transported in rolls, these multi-purpose laminates are available in unlimited lengths and a wide variety of sizes. They have a low overall thickness so they can be coated, require minimal preparation, and their clean edges with no exposed fibres are thanks to the pultrusion process.
For bonding the CarboDur Plates in this project, Sikadur-30 was specified. This thixotropic, structural two-part adhesive based on a combination of epoxy resins and special fillers is easy to mix and apply, requires no primer, and provides high creep resistance under permanent loads. It offers high initial and ultimate mechanical resistance as well as high abrasion and shock resistance. Hardening is not affected by high humidity and it hardens without shrinkage.
For strengthening of the church roof, Sika CarboDur Plates were placed at intervals on the ceiling. Once the reinforcing roof props were removed (after seven days), finishing of the ceiling could take place. This involved brushing Sikadur-30 over the CarboDur Plates before a layer of Cretestone plaster could be applied.
In total, 186m of Sika CarboDur Plates S512 and 11 x 6kg of Sikadur-30 were used in two days to save this important community structure. The congregation of Jeffrey’s Bay NG Kerk can rest assured that their church has been renovated and strengthened with the highest quality products that Sika is renowned for.