无砂透水混凝土试验研究

Experimental Study of Sand-Free Pervious Concrete

为解决透水混凝土强度与透水性的矛盾,配制出高性能透水混凝土,研究骨料类型以及骨料级配、水胶比、孔隙率、硅灰等因素对透水混凝土抗压强度与透水性等性能的影响。结果表明:骨料类型和骨料级配对透水混凝土性能影响显著,5～10 mm和10～15 mm各50%的混合级配的强度比5～10 mm单一级配提高15%,但透水性降低32%;相同条件下,辉绿岩骨料的透水混凝土强度要高于花岗岩11%,透水系数高于花岗岩骨料28%。水胶比和孔隙率对透水混凝土性能影响明显,为兼顾透水混凝土强度和透水性要求,实验中推荐最佳水灰比范围为0. 25～0. 30,孔隙率合理范围为15%～18%;当水胶比为0. 25时,最佳硅灰掺量为6%。

In order to solve the contradiction between strength and permeability of pervious concrete, high-performance pervious concrete was prepared. Effects of aggregate type, aggregate gradation, water-binder ratio, porosity and silica fume on compressive strength and permeability of pervious concrete were studied. The results show that the aggregate type and aggregate grade paired pervious concrete has significant effect on its performance, and the strength of 50% mixed grades of 5-10 mm and 10-15 mm is 15% higher than that of 5-10 mm single grade, but the permeability is 32% lower. Under the same conditions, the pervious concrete strength of diabase aggregate is higher than 11% of granite, and the pervious coefficient is higher than 28% of granite aggregate. The water cement ratio and porosity have obvious influence on the performance of pervious concrete. In order to give consideration to both strength and permeability requirements of pervious concrete, the range of optimal water cement ratio is recommended to be 0.25-0.30 in the experiment, and the reasonable range of porosity is 15%-18%.When the water-cement ratio is 0.25, the optimum silica fume content is 6%.