本文列举砂子粗细(以细度模数表示)和级配对混凝土影响的试验结果,表明砂子粗细对混凝土坍落度、砂率有显著的影响,对强度则没有影响;当细度模数固定,级配变化时对混凝土坍落度也有影响,但只是颗粒过分集中分布于某1级或相邻2级、或颗粒成间断分布时影响较大,由于通常不会出现这些特殊级配,所以实用中只需控制细度模数,不需控制级配。 In this paper, the results of sand thickness (expressed in fineness modulus) and gradation on concrete are listed. The results show that the sand thickness has a significant influence on concrete slump and sand rate, but has no effect on the strength. When the fineness modulus is fixed, Grading changes also affect the slump of concrete, but only the particles are too concentrated in a certain level or adjacent to the second level, or particles into a larger distribution of intermittent impact, because usually do not appear these special grading, so practical In the control of fineness modulus only, without control gradation.