一、问题的提出众所周知,粉煤灰应用于砼中其细度影响新鲜砼和硬化砼的性能,这与研究者公认的粉煤灰的活性及细粒子含量有直接关系。关于粉煤灰细度的评价,ASTM标准C618和BS标准3892以45μm筛余量为指标;有些规范则以气体渗透法测得的比表面积值为指标。然而,无论是筛余量还是比表面积值都不是评价份煤灰细度的最佳指标。因为前者只考虑了大于或小 First, the question raised As we all know, the fineness of fly ash used in concrete affect the performance of fresh concrete and hardened concrete, which is directly related to the activity of researchers recognized fly ash and fine particle content. As for the evaluation of fineness of fly ash, ASTM standard C618 and BS standard 3892 are taken as indices for 45μm sieve margin; some specifications are based on the specific surface area value measured by gas permeation method. However, neither sieve margin nor specific surface area value is the best indicator to evaluate the fineness of coal ash. Because the former only considered larger or smaller