降雨强度对透水沥青混凝土净污能力影响研究

Study on Influence of Rainfall Intensity on Purifying Capacity of Permeable Asphalt Concrete

为定量评估降雨强度对透水沥青混合料净化路面径流能力的影响,基于搭建的足尺道路路面平台设计了5种降雨强度下单、双层透水沥青混凝土的人工降雨模拟试验,测定了流经透水沥青混合料前后模拟径流雨水的代表性污染物浓度。结果表明:透水沥青混凝土能有效净化径流污染,且双层透水沥青混凝土的污染净化能力显著优于单层透水沥青混凝土,对悬浮物(SS)、总磷化合物(TP)、重金属锌(Zn)、重金属铅(Pb)、总氮化合物(TN)、化学需氧量(COD)的去除率分别达到80.25%、74.13%、70.30%、65.14%、63.75%、61.38%;随着降雨强度的增大,透水沥青混凝土对径流污染物的净化能力逐渐减弱,通过分析层数、降雨强度对透水沥青混凝土污染物净化率的影响,提出了层系数α和雨强折减系数β,可以通过人工降雨模拟试验结果推算一定降雨强度下实际透水沥青混凝土路面的污染物净化能力,为透水沥青混凝土路面的量化环境评价提供依据。

To quantitatively evaluate the impact of rainfall intensity on the ability of permeable asphalt mixtures(PAM)to purify the pavement runoff,the artificial rainfall simulation tests of the single-layer and double-layer PAM under five rainfall intensities are designed according to the erected full-scale road pavement platform to detect the representative pollutant concentrations of the simulated runoff rainwater before and after flowing through PAM.The results show that PAM can effectively purify the runoff pollution,and the pollution purifying capacity of double-layer PAM is significantly better than that of single-layer PAM.The removal rates of suspended solids(SS),total phosphorus compounds(TP),heavy metal zinc(Zn),heavy metal plumbum(Pb),total nitrogen compounds(TN)and chemical oxygen demand(COD)by PAM are 80.25%,74.13%,70.30%,65.14%,63.75%and 61.38%respectively.With the increase of rainfall intensity,the purification capacity of PAM to runoff pollutants is gradually weakened.The layer coefficientαand rainfall intensity reduction coefficientβare proposed by analyzing the impact of layer coefficient and rainfall intensity on the pollutant purifying rate of PAM.The pollutant purifying capacity of the actual PAM pavement under certain of rainfall intensity can be calculated by the test results of artificial rainfall simulation,which provides the basis for the quantitative environmental evaluation of PAM pavement.