WATERPROOFING OF BRIDGE DECKS PRACTICE IN SOUTH AFRICA

Traditionally it was not considered necessary to waterproof bridge decks in South Africa as no serious corrosion problems of reinforcing steel had been recorded in coastal areas. However, with more emphasis now being placed on bridge inspections many cases of water seeping through bridge decks have been recorded. Laboratory testing of cored concrete samples have shown above normal choride levels, and any further increase in chloride levels could trigger the commencement of steel corrosion. The bridges investigated are located close to the coast and are exposed to the prevailing salt laden winds. It was decided that the only effective way to halt the ingress of further chlorides into the concrete was to waterproof the top surfaces of the concrete blocks. Various overseas bridge waterproofing systems were reserached, some of which were available locally as building waterproofing systems. (A) For the covering abstract see ITRD E106702.