Freezing and Thawing Resistance of High Slag Content Concrete

It is essential that concrete structures should withstand the conditions for which they have been designed for long periods of time. The lack of durability may be caused either by the environment to which the concrete is exposed or by the concrete itself. In this study, the resistance to freezing and thawing of high-slag content concrete (HSC concrete) is discussed for the purpose of utilizing ground granulated blast furnace slag (GGBS) as an ingredient of cement. The slag content in cement ranged from 0 to 95% by weight of total cementitious materials and the fineness of slag was 816 sq m/kg. The resistance of air entrained (AE) concrete with a slag content of 70% was superior or comparable to that of slag free concrete, whereas AE concretes had questionable performance in the case of slag content of 85%, and had less ability in the case of 95% slag content with respect to freezing and thawing resistance. HSC concretes could have satisfactory high resistance to freezing and thawing by using an air-entraining high range water-reducing admixture (AEHW admixture), even if the slag content was 95%. Thus, the concrete with AEHW admixture, which are called SP concretes, would be recommended for freezing and thawing conditions with respect to the use of HSC concrete.