Freeze-thaw durability of Portland cement and silica fume concretes
ABSTRACT: An experimental research was carried out to investigate the effect of silica fume on the freeze-thaw resistance of concretes subjected to slow freeze-thaw cycles. Concrete specimens were exposed to slow freeze-thaw cycles after 7 and 28 days of initial curing. The deterioration and residual strength of concrete specimens were assessed after 25, 50 and 100 cycles. The results showed that the use of air entrainment and the initial curing period are the most significant factors affecting the freeze-thaw durability of concrete. The absolute values of residual strength of mixes containing silica fume were significantly higher than those of Portland cement concrete. However, expressing the results as percentage of the strength of control specimens showed that silica fume has little or no effect on the relative residual strength. Nonetheless, specimens with silica fume showed less deterioration compared to specimens without silica fume.