孔隙率对透水性沥青路面渗透性能的影响规律

Influence of Porosity on Seepage Characteristic of Pervious Bituminous Pavement

为研究不同结构层孔隙率对透水性沥青路面渗透性能的影响规律,建立了透水性沥青路面渗透性能分析模型;基于多孔介质渗流理论,采用计算流体动力学(CFD)方法分析了不同结构层孔隙率对透水性沥青路面渗透性能的影响规律.结果表明:雨型(降雨强度)对透水性沥青路面渗透性能的影响比较明显,在Ⅰ型雨型(降雨强度为18.8mm/h)条件下透水性沥青路面的渗透速率大于其他雨型;当透水沥青混凝土层孔隙率(体积分数,下同)为15%~25%时,其对透水性沥青路面渗透性能的影响较小,大孔隙沥青稳定碎石基层孔隙率对透水性沥青路面渗透性能的影响比较明显,并且随孔隙率增大其渗透性能增强;当级配碎石层和砂垫层孔隙率大于35%时,其对透水性沥青路面渗透性能的影响较小.该研究成果将为透水性沥青路面结构以及混合料配比设计提供重要指导.

In order to investigate the seepage characteristic of pervious bituminous pavement, a model was proposed to simulate the seepage characteristic of pervious bituminous pavement. The influence of the po- rosity on the seepage characteristic of pervious bituminous pavement was investigated based on the porous media seepage theory. The simulation results show that the permeation rate is notably influenced by the rain type for the pervious bituminous pavement, and is larger under [ rain type（rainfall intensity is 18.8 mm/h） than that under the other rain types. The influence of the porosity of permeable asphalt con crete layer is slight on the permeation rate of pervious bituminous pavement. The permeation rate of pervi ous bituminous pavement is significantly impacted by the porosity of macropore asphalt stabilized macadam base layer, and increases with the increase of that. The influences of the porosity of graded gravel layer and sand cushion layer are slight on the permeation rate of pervious bituminous pavement when the porosi ty of that is more than 35% （by volume）. These results will provide some constructive instructions for the design of the structure and asphalt mixed material compounding ratio on pervious bituminous pavement.