低胶凝材料用量透水混凝土性能研究

Study on the Performance of Pervious Concrete with Low Binding Material Content

为了降低透水混凝土中胶凝材料的用量并提高透水性,通过调整水胶比、外加剂等因素研究了低胶凝材料用量透水混凝土的孔结构、透水性和强度。结果表明:减小浆体的流动性会增大透水混凝土的实际堆积体积,导致透水混凝土的实际孔隙率增大;低胶凝材料用量对透水混凝土的机械强度不利,但可以通过优化水胶比(w/b)和外加剂制备出单位体积胶凝材料用量小于300 kg,透水系数大于6 mm/s,抗折强度2.5 MPa,抗压强度大于15 MPa的透水混凝土,完全满足人行步道等使用环境的需求。

To reduce the cost of binding material and improve the permeability of pervious concrete,the effects of water-binder ratio and admixtures on pore structures,water permeability and strength of pervious concrete with low binding material content are studied.The results show that a paste with low flowability can increase the actual accumulation volume of pervious concrete,resulting in the increase of porosity.Low binding material content is bad for mechanical strength,but a pervious concrete with binding material of 300 kg/m 3,permeability of 6 mm/s,bending strength of 2.5 MPa and compressive strength of more than 15 MPa can be prepared by optimizing the w/b ratio and admixture,which meets the needs of usage method like pedestrian walkways.