石英砂对水泥浆性能及其水膜厚度影响实验研究

Experimental Study on Effect of Quartz Sand on Properties and Water Film Thickness of Cement Paste

石英砂是强度高、耐磨性好、化学性能稳定的硅酸盐矿物,其主要矿物成分为SiO_2,能与水泥水化产物Ca(OH)_2进行二次水化反应.为探索其对水泥浆性能及其水膜厚度的影响,研究测量了30组不同水胶比、不同石英砂掺量的水泥浆的流动性能、粘聚性和抗压强度.为揭示石英砂水泥浆的流变性能控制机理,本研究进一步测量了5组不同石英砂掺量水泥浆的填充密度,并基于填充密度测量结果计算出各水泥浆试样配比的水膜厚度,探索水膜厚度对石英砂水泥浆流变性能的影响.实验结果表明,石英砂的掺入能增加水泥浆的流动性能,且石英砂掺量越大,水泥浆流动性能越好,但水泥浆的抗压强度随石英砂掺量的增大而逐渐降低.石英砂掺入对填充密度影响不大,水膜厚度为流动性主要控制因素,水泥浆的流动性能随水膜厚度增大而增大.

Quartz sand is a kind of silicate material with high strength, high abrasion-resistance and high chemical stability. Its main mineral composition is SiO2 and can react with Ca（OH）2 to produce gel for strength development. To study the effect of quartz sand on performance and water film thickness, the flowability, cohesiveness and strength of 30 mixes of cement paste with different water/binder ratio were measured. The packing density of the packing density of 5 different powder mixes with various quartz sand content was measured. The water film thickness of each cement paste mix was calculated based on the packing density test. The influence of water fihn thickness on the flowability of cement paste was discussed. Results demonstrated that addition of quartz sand would increase the flowability, but impair the compressive strength. Packing density results showed that the addition of quartz sand had little effect on packing density. The water film thickness is the major governing factor of flowabilty of quart sand cement paste.