基于可压缩堆积模型的透水混凝土配合比设计

Mix Proportion Design of Pervious Concrete Based on Compressible Packing Model

基于可压缩堆积模型,以全孔隙率为设计指标,提出了一种考虑成型过程和集料级配影响的透水混凝土配合比设计方法。该方法首先根据可压缩堆积模型挑选出干堆积密实度较高的级配集料,引入反映成型过程影响的比例因子λ建立了集料在透水混凝土中的堆积密实度与其干堆积密实度之间的关系,进而确定出单位体积透水混凝土的集料用量;然后根据集料用量和水灰比,计算得到透水混凝土的水泥浆体体积和水泥用量。对依据该方法设计的透水混凝土性能验证试验表明,实测全孔隙率与设计全孔隙率非常吻合,达到预设目标;透水混凝土强度随小粒径集料体积分数的变化趋势与集料干堆积密实度的相近,但是并非干堆积密实越高则强度越高,强度还受到集料粒径的影响。

Based on the compressible packing model and the total porosity was taken as the main mix proportion design parameter, a mix proportion design method of pervious concrete considering the influence of molding process and aggregate gradation was proposed. In this method,the graded aggregates with high dry packing density were selected based on the compressible packing model,the relationship between the packing density of the aggregates in pervious concrete and its dry packing density was established by introducing a scale factor λ which reflected the influence of the molding method,then the aggregate mass per unit volume of pervious concrete was determined; and the paste volume and cement mass were calculated according to the aggregate mass and water-cement ratio. the pervious concrete has been formulated according to this method to validate it,the results demonstrate that the gap between the measured total porosity and the design total porosity is very small,which indicates that this method achieves the design object,and the strength variation tendency against the volumetric fraction of fine aggregates is similar to that of aggregate＇s dry packing density,but not the higher the dry packing density the higher the strength,the strength is also affected by the aggregates size.