RESISTANCE TO FREEZING AND THAWING ATTACK OF CONCRETE WITH BLAST FURNACE SLAG FINE AGGREGATE

Abstract

 Concrete cured by steam can not have high resistance to freezing and thawing attack even if AE agent is added at mixing. However, the concrete with blast furnace slag fine aggregate can have high resistance to freezing and thawing attack even if AE agent is not mixed. That is why the concrete with blast furnace slag fine aggregate can have high resistance to freezing and thawing attack even if it is cured by steam. The calcium hydroxide deposits around the coarse aggregate in ordinary concrete. The calcium hydroxide is easier to dissolve in water at low temperature. The water is accumulated in a gap made by dissolved calcium hydroxide. The accumulated water expands when it freezes and cracks yields around aggregate. In this paper, it is shown that calcium hydroxide does not deposit around the aggregate and the resistance to freezing and thawing of concrete is improved when blast furnace slag is used as fine aggregate.