Performance of a Different Pozzolanic Cement Concretes Under Cyclic Wetting and Drying

As part of a comprehensive research project on the durability of on and offshore concrete structures in the Persian Gulf, a simulation laboratory has been made use of. The present study consists mainly of nine month exposure tests in the tidal and atmospheric zone conditions in the laboratory. Concrete specimens containing different supplementary materials, namely silica fume, blast-furnace slag, diatomous earth and trass, have been thoroughly investigated. The tests conducted include compressive strength, volume changes, half cell potentials, carbonation, and chloride diffusion, all at different ages. With respect to the alternate cycles of wetting and drying, the superior performance of silica fume was followed by the diatomous earth pozzolan. However, all concrete mixtures containing natural and artificial pozzolans showed better performance when compared with the plain portland cement control concrete mixtures.