Fly ash (FA) has been an important ingredient for engineered cementitious composite (ECC) with excellent tensile strain capacity\nand multiple cracking. Unfortunately, the frost resistance of ECC with high-volume FA has always been a problem. This paper\ndiscusses the influence of silica fume (SF) and ground-granulated blast-furnace slag (GGBS) on the frost resistance of ECC with\nhigh volume of FA. Four ECC mixtures, ECC (50% FA), ECC (70% FA), ECC (30% FA + 40% SL), and ECC (65% FA + 5% SF), are\nevaluated by freezing-thawing cycles up to 200 cycles in tap water and sodium chloride solution. The result shows the relative\ndynamic elastic modulus and mass loss of ECC in sodium chloride solution by freeze-thaw cycles are larger than those in tap water\nby freeze-thaw cycles. Moreover, the relative dynamic elastic modulus and mass loss of ECC by freeze-thaw cycles increase with\nFA content increasing. However, the ECC (30% FA + 40% SL) shows a lower relative dynamic elastic modulus and mass loss, but\nits deflection upon four-point bending test is relatively smaller before and after freeze-thaw cycles. By contrast, the ECC (65% FA\n+ 5% SF) exhibits a significant deflection increase with higher first cracking load, and the toughness increases sharply after freezethaw\ncycles, meaning ECC has good toughness property.
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