为研究不同模拟条件下透水沥青混合料的渗透特性和净化能力,在室内制备PAC-13型透水沥青混合料马歇尔试件,并对其在风干与不风干两种模拟条件下的渗透系数与污染物净化率进行测定,研究渗透系数与污染物净化率的变化规律,分析风干效应对透水沥青混凝土渗透系数衰变速率的影响.结果表明:合理控制空隙率,可确保透水沥青混凝土的透水性能和净化能力;渗透系数的衰减意味着污染物去除率的提高,原空隙内壁和截留颗粒组成的新空隙结构强化了透水沥青混凝土对各种污染物的净化能力.

Pavement runoff is recognized as a primary source of non-point pollution in the urban area. It is difficult to treat the runoff-pollutants from different pavements because of complex distribution characteristics and influencing factors. This study presents the results of an experimental investigation aimed at determining the impact of three types of urban pavements, i.e., portland cement concrete pavements (PCC), dense asphalt concrete pavements (DAC) and permeable asphalt concrete pavements (PAC) on the rainfall-runoff process, concentration levels, and spatiotemporal distribution characteristics of typical runoff-pollutants. Runoff samples from the three types of urban pavements were collected and analyzed at different time-intervals beginning from runoff formation. The results indicated that PAC could better intercept and retain runoff-pollutants than DAC and PCC. In addition to the types of pavements, road-traffic characteristics and the surrounding environment significantly impacted the event mean concentrations of the selected rainfall events. Concentrations of suspended solids and heavy metals were higher at intersections and crosswalks, while those of organic pollutants were high in commercial areas. Besides, three parameters were proposed to characterize the first-flush effect intensity for runoff-pollutants. These findings help better understand the spatiotemporal distribution characteristics of runoff-pollutants from different types of urban pavements, which could also help strategically select measures to treat pavement runoff pollution.

It is now more popular to use basalt fibers in the engineering programs to reinforce the crack resistance of asphalt mixtures. However, research concerning the impact of the basalt fiber diameter on the macro performance of AC-13 mixtures is very limited. Therefore, in this paper, basalt fibers with three diameters, including 7, 13 and 25 μm, were selected to research the influences of fiber diameter on the crack resistance of asphalt mixtures. Different types of crack tests, such as the low temperature trabecular bending test (LTTB), the indirect tensile asphalt cracking test (IDEAL-CT), and the semi-circular bend test (SCB), were conducted to reveal the crack resistance of AC-13 mixtures. The entire cracking process was recorded through the digital image correlation (DIC) technique, and the displacement cloud pictures, strain, average crack propagation rate (V) and fracture toughness (FT) indicators were used to evaluate the crack inhibition action of the fiber diameter on the mixture. The results showed that the incorporation of basalt fiber substantially improved the crack resistance, slowed down the increase of the displacement, and delayed the fracture time. Basalt fiber with a diameter of 7 μm presented the best enhancement capability on the crack resistance of the AC-13 mixture. The flexibility index (FI) of the SCB test showed a good correlation with V and FT values of DIC test results, respectively. These findings provide theoretical advice for the popularization and engineering application of basalt fibers in asphalt pavement.

The removal of particulate matter (PM) by filter media during filtration process can mitigate the pavement runoff pollution effectively. However, this process also makes the filter media prone to clogging. To better understand the size ranges of PM captured by filter media and the subsequent impact on the clogging process, filtration test and clogging test were conducted on five types of filter media. The effect of layer thickness and grain size of different filter media on particle removal efficiency was evaluated, based on the results of PM removal rate and the particle size distribution. The subsequent long-term clogging characteristics of different filter media were also investigated. The results showed that filter media presented different capabilities to capture PM, which could be enhanced by less layer thickness or finer grain size. Normally, PM with the size range of over 49 μm could be captured effectively if proper layer thickness and grain size of filter media were selected. Besides, PM removal rate was not related to the clogging resistance of filter media. Though it can capture a larger amount of PM, Vesuvianite still maintained remarkable clogging resistance. The results will be beneficial to filter media selection and system design optimization for pavement runoff treatment.

为研究不同类型的城市绿地径流污染特征,以扬州市为研究区域,选取了公园绿地、小区绿地、工业区绿地、文教区绿地和道路绿地等五种不同类型的城市绿地,采集径流雨水水样并测试其中典型污染物的浓度.结果表明:不同类型城市绿地径流雨水均存在水质污染情况,其中道路绿地、工业区绿地污染严重,公园绿地、小区绿地次之,文教区绿地污染程度最低;城市绿地初始冲刷效应不强烈,大部分污染物呈现中等程度的初期冲刷效应;不同类型城市绿地污染物的赋存状态不同,其中TN(总氮)、Zn、Pb主要以颗粒态存在,COD(化学需氧量)、TP(总磷)主要以溶解态存在.

为研究路域土壤重金属的空间分布特征,以镇江市润州区龙门港路(透水沥青路面)与港前路(密实沥青路面)作为研究对象,探究土壤中重金属Pb、Zn的空间分布特征.通过分析路面径流雨水中Pb、Zn污染物含量,得出路面径流对土壤中重金属Pb、Zn含量的影响,并采集了80个土壤样品进行测试,利用单因子污染指数法、综合污染指数法进行了土壤重金属污染评价.结果表明:路面径流污染是导致土壤重金属含量较高的重要因素;城市道路重金属污染非常严重;透水沥青路面对重金属污染物具有一定的截留作用,减少了重金属进入土壤深处.

With the progress of modern society and the vigorous development of the automobile industry, traffic congestion occur continuously in urban roads. In addition, with the acceleration of the urbanization process in our country, the number of urban population and the number of cars are increasing constantly, which leads to the increasingly serious traffic congestion, and a series of traffic problems and environmental problems. The project selected Hanjiang Road in Yangzhou as the research object, and compared the current city fast track intersection vehicle exhaust emissions with green wave traffic signal control vehicle exhaust emissions under uniform traffic to highlight its energy saving effect, the benefit and improvement of the air environment. It also provided a theoretical reference to promote green traffic signal control for the construction of ecological society.