【摘要】 针对国家标准GB/T 14684—2001《建筑用砂》关于配制C60以上混凝土所用机制砂石粉含量限值3%(质量分数,下同)的规定,研究了不同石粉含量(3.5%,7.0%,10.5%,14.0%)与不同粉煤灰掺量(0,11.3%,17.0%)对C60机制砂高性能混凝土工作性、抗压强度、弹性模量、干缩率、氯离子扩散系数和抗冻性的影响,以及石粉作掺和料对C60机制砂高性能混凝土工作性和抗压强度的影响.据此,提出了在采用机制砂配制C60高性能混凝土时,机制砂中石粉的含量可以放宽到10.5%,机制砂混凝土中粉煤灰的掺用可以不考虑机制砂石粉含量的高低,且机制砂中的一部分石粉可作为掺和料使用,其替代量大致为水泥用量的11.3%.更多还原

【Abstract】 The stone dust finer than 75 μm inevitably exists in the manufactured sand.According to GB/T 14684—2001 of the Chinese national standard for Sand for Building,the content of stone dust in manufactured sand used in C60 concrete shall be less than 3%.The paper presents the results of studies of C60 high performance concrete(HPC) prepared from manufactured sands containing 3.5%,7.0%,10.5% and 14.0% of stone dust,and 0,11.3% and 17.0% of fly ash.Besides the workability and compressive strength of C60 manufactured sand HPC,modulus of (elasticity,) drying shrinkage,chloride diffusion coefficient as well as freezingthawing resistance were determined.Moreover,replacement of cement with the stone dust as mineral admixture was studied.Hereby,it is put forward that the stone dust content can be as much as 10.5% when(using) manufactured sand to prepare C60 HPC,and the influence of fly ash on C60 manufactured sand HPC has nothing to do with content of stone dust in the manufactured sand,and part of stone dust can be used as mineral admixture,the replacement rate is approximately (11.3%) of cement.更多还原