CONCRETE COVER REQUIREMENTS FOR RC STRUCTURES IN THE MARINE ENVIRONMENT

摘要

The marine reinforced concrete (RC) structures in Taiwan have been investigated for over ten years. The field survey include concrete cover layer and cores samples drilled. The tests include the chemical analysis, and the chloride diffusion rate. The test data show that the content of Cl- and MgO in the existing marine RC structures are very high. The main factor that controls the corrosion of steels in the RC structures is the penetration of Cl~-.The test data also show that the more nearshore of structures are, the more accurate distribution of chloride penetration in the concrete will be. For 50 years service life of steels in RC structures of marine environment, a minimum depth of 11.4 cm concrete cover layer with better quality concrete is required in Taiwan.