Construction World August 2019

damages and repaired during the concrete preparation stage. Any unevenness or protrusions were grinded flush in the concrete preparation stage. The product Sikadur-330 was used together with the SikaWrap carbon fibre fabric. All the areas that were strengthened were prepared by means of grinding before applying the SikaWrap. Sikadur-330 was applied as a bedding layer onto the clean concrete surface. The SikaWrap was then applied onto the wet epoxy adhesive and the surface of the cloth was rolled with a ribbed roller. This was to ensure that all trapped air or bubbles were removed from the layered material and that the resin was pushed through the cloth. A second coat of Sikadur-330 was applied to cover the fabric evenly to ensure complete wet out of the SikaWrap. One of the key challenges during this project was that works had to be completed under live traffic conditions. Therefore, the N4 had to remain open during the rehabilitation process. Over and above the traffic conditions, crocodiles in the river below posed an additional safety risk, especially during the rainy season when flooding was an issue. Regardless of the challenges faced, the rehabilitation works were successfully completed in six months. 

“ The shear and flexural cracks were believed to have been related to thermal loading caused by the locked bearings. ”

HP: CHRYSO

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CONSTRUCTION WORLD AUGUST 2019