TEST RESEARCH ON THE FREEZING-THAWING RESISTANCE PERFORMANCE OF HIGH-STRENGTH CONCRETE WITH SINGLE ADMIXTURE AND DOUBLE ADMIXTURES

The fast freeze-thaw tests with fresh water on high strength concrete ( C60 ) with fly ash or slag and composite admixture，as well as the one without admixtures were conducted． The results showed that for the concrete with admixtures ( slag and fly ash) ，the mass-loss rate was the smallest and the relative dynamic modulus of elasticity was reduced slowest，meanwhile the surface was denuded slightest，indicating a best freezing-thawing resistance performance．For the concrete with 50% slag and concrete without mineral admixtures，the mass-loss rate，the relative dynamic modulus of elasticity and the surface denudation were about the same，meanwhile their freezingthawing resistance performance was a little worse than the concrete with admixtures ( slag and fly ash) ．For the concrete with 50% fly ash，the mass-loss rate and the relative dynamic modulus of elasticity reduced fastest，and the surface was denuded seriously，indicating a worst freezing-thawing resistance performance．