1前言水泥防水砂浆作为刚性防水材料,在防渗、堵漏工程中应用广泛。水泥防水砂浆的品种很多,抗渗性能也有所不同,但其组成材料不外乎为水泥、细集料和改性材料。细集料主要起骨架作用,本文研究表明砂子的细度模数大小对防水砂浆抗渗性能有着不同的影响。2原材料抗折抗压强度(MPa)(1)砂子:选用细砂、中砂、粗砂。其细砂技术数据为:细度模数1.5、含泥量1.2%、泥块含量0.8%、堆积密度1320kg/m3、紧密密度1470kg/m3、空隙率51%。其中砂技术数据为:细度模数2.4、含泥量0.6%、泥块含量 1 Introduction Cement waterproof mortar as a rigid waterproof material, seepage control, plugging a wide range of applications. Many varieties of waterproof mortar, impermeability is also different, but nothing more than the composition of the cement, fine aggregate and modified materials. The fine aggregate mainly plays the role of skeleton. The study shows that the fineness modulus of sand has different influence on the impermeability of waterproof mortar. 2 flexural strength of raw materials compressive strength (MPa) (1) sand: the choice of fine sand, sand, coarse sand. The fine sand technical data: fineness modulus 1.5, clay content 1.2%, mud content 0.8%, bulk density 1320kg / m3, compact density 1470kg / m3, the porosity of 51%. Sand technology which is the data: fineness modulus 2.4, containing 0.6% mud, mud content