Durability of silica fume and ggbs concrete in a tidal zone

Abstract

This paper summarises investigations that were conducted to assess the durability of plain and blended type II Portland cement exposed to marine tidal environments. In this research the performance of cement paste and concrete mixes incorporating 7 and 10% silica fume as a cement replacement was investigated in three exposure conditions with seven days’ initial curing in potable water. The performance of plain and blended cements was evaluated by monitoring changes in compressive strength and capillary absorption. The results show that plain type II Portland cement performed better than blended silica fume cement under cyclic wetting and drying conditions. Silica fume specimens under cyclic wetting and drying conditions in simulated seawater exhibited higher strength loss in comparison with plain type II Portland cement when cured under potable water. In addition, the greater the silica fume amount used in the mixes, the more the capillary water absorption under tidal zone exposure and/or under wetting and drying simulation. Further, the ternary-blended ground granulated blast-furnace slag mix was the worst-performing mix in all exposure conditions. An extended initial curing time is recommended for these types of mixes.