基于骨料特性和浆体厚度的透水混凝土配合比设计

Mix Proportion Design of Permeable Concrete Based on Aggregate Properties and Mortar Thickness

传统的透水混凝土配合比设计主要以骨料堆积密度和目标孔隙率为主要设计参数,缺乏强度设计依据,且实际孔隙率与目标孔隙率相差较大,透水性能难以保证。提出一种基于骨料特性和浆体均匀包裹模型的透水混凝土配合比设计方法,其主要引入骨料比表面积和浆体厚度2个参数,据此设定合理的浆体厚度和水胶比,再通过计算所得骨料的比表面积确定浆体的体积,最终确定配合比。试验表明:该方法可有效地以浆体数量控制有效孔隙率的大小,透水混凝土的力学性能符合设计要求,透水性能良好,能适应不同骨料特性和强度要求的透水混凝土配合比设计要求。

The traditional permeable concrete mix design is mainly based on two design parameters of aggregate packing density and target porosity. However, it lacks strength design basis, the actual porosity is quite different from the target porosity, and the permeable performance is difficult to guarantee. To this end, a design method of permeable concrete mix proportion based on aggregate characteristics and uniformly wrapped mortar model is proposed. It mainly introduces two parameters of aggregate specific surface area and mortar thickness, and accordingly determines the reasonable mortar thickness and water-binder ratio. Then the volume of mortar is determined according to the calculated aggregate specific surface area and finally determines the mix proportion. The test shows that such method can effectively control the effective porosity by the volume of mortar and the mechanical properties of the permeable concrete can meet the design requirements with good permeable performance. Moreover, it can adapt to permeable concrete mix proportion design with different aggregate characteristics and strength requirements.