水膜厚度对多孔沥青路面摩擦摆值的影响

Effect of Water Film Thickness on Frictional Resistance of Porous Asphalt Pavement

多孔沥青(Porous Asphalt Concrete,PAC)路面虽具有排水功能,但在短时强降雨情况下,降雨强度超过了路面的排水能力,路表就会形成不同程度的水膜,这对高速行驶的汽车造成了巨大的安全隐患.为评价多孔沥青路面在不同水膜厚度下的抗滑安全性能,通过在室内制备6种多孔沥青混合料大车辙板试件,利用摆式摩擦系数测定仪测得其摩擦摆值,并与密级配沥青混合料试件(SMA-13和AC-13)的结果进行对比分析,提出了用水膜厚度表征的多孔沥青路面摩擦系数计算模型,并在广西南宁绕城高速公路进行了实证.研究结果表明,公称最大粒径对有水膜多孔沥青路面的抗滑能力有较大影响,PAC-5要好于PAC-13和PAC-10,PAC-16抗滑能力最好;水膜厚度对SMA抗滑能力影响的敏感性较小,临界水膜厚度为0.07 mm,同样水膜厚度下SMA摩擦系数比PAC更大;9.5 mm筛孔通过率对PAC的抗滑性能有影响,但并非呈线性相关关系;通过9.5 mm尺寸筛孔的质量分数为69%多孔沥青混合料对应的摩擦摆值最大,其抗滑能力最佳.

Porous asphalt concrete(PAC)pavement has good drainage capability;however,during heavy rainfall,the pavement s drainage capacity may be insufficient,causing different levels of water film formation on the road surface,which poses potential safety hazards to high-speed vehicles.To evaluate the skid resistance safety performance of PAC under different water film thicknesses,six large rut plate specimens of porous asphalt mixture were prepared,and their friction pendulum values were measured using a pendulum friction coefficient tester.The results were compared with those of dense graded asphalt mixture specimens(SMA-13 and AC-13).A calculation model for the friction coefficient of porous asphalt pavement was proposed,which considers water film thickness as a characteristic.The demonstration was conducted on Nanning Ring Expressway in Guangxi.The results indicate that the nominal maximum particle size has a significant effect on the skid resistance ability of porous asphalt pavement with a water film,where PAC-5 has better skid resistance ability than PAC-13 and PAC-10,and PAC-16 exhibits the best skid resistance ability.The critical water film thickness is 0.07 mm,and the friction coefficient of SMA is greater than that of PAC under the same water film thickness.The passing rate of 9.5mm sieve has an effect on the skid resistance performance of PAC,but it is not a linear correlation.The porous asphalt mixture with a 9.5 mm sieve hole passing rate of 69%exhibits the largest corresponding friction pendulum value and the best skid resistance ability.