车辙对大空隙沥青路面横向排水影响的室内模拟测试

Laboratory evaluation of the effect of longitudinal rutting on transversal permeability in porous asphalt pavement

为了研究纵向车辙对大空隙沥青路面横向排水的影响,研发了大空隙沥青混合料渗水系数的室内测试仪,该仪器可模拟路面横坡和雨水在大空隙沥青混合料中的流动过程.采用车辙试验仪对8种类型的OGFC沥青混合料试件进行往复荷载作用来模拟车辙变形,并利用研发的渗水系数测试仪,测试具有不同车辙深度的沥青混合料横向渗水系数,计算得到因车辙引起的混合料渗水系数衰减度.结果表明:车辙会明显降低大空隙沥青混合料的横向渗水系数;动稳定度与渗水系数衰减度无明显关系,而大空隙沥青混合料的车辙深度与渗水系数衰减度具有一定的线性关系,因此可作为控制渗水系数衰减的指标;增大集料的公称最大粒径、使用高黏改性沥青、增大混合料空隙率能有效降低车辙引起的排水系数衰减程度.

To investigate permeability loss or reduction due to longitudinal rutting,a permeameter was developed with consideration of both rainwater flowing procedure and the pavement transversal slope. Wheel rutting tests were conducted on the eight types of open graded friction course（ OGFC）samples to simulate the rutting deformation. The developed permeameter was used to test the permeability of OGFC samples with different rutting depths. The permeability loss due to rutting deformation was calculated. Results showthat permeability loss due to deformation-related clogging is significant. The permeability coefficient has no significant relationship with the dynamic stability,but it decreases linearly with the increasing rutting depth of the OGFC mixtures. The rutting depth is recommended as a design index to control the permeability loss of the OGFC mixture rather than the dynamic stability. Permeability loss due to deformation-related clogging can be reduced effectively by using large nominal maximum aggregate size,high viscosity asphalt binder and large air voids.