超薄磨耗层沥青混合料的抗剪性能

Shear property of ultra-thin wearing course asphalt mixture

基于单轴贯入试验和无侧限抗压试验,研究了原材料参数和试验条件对沥青混合料抗剪强度的影响.通过室内试验研究了SBS掺量、补强剂掺量和级配类型对超薄磨耗层高温稳定性、低温抗裂性、水稳定性和抗剥落性能的影响.试验结果表明：骨架结构混合料的抗剪性能优于悬浮密实结构,SBS改性沥青混合料的抗剪性能优于基质沥青混合料;最佳沥青用量下的混合料抗剪强度较大,且补强剂可有效改善混合料的抗剪性能;高温条件和低速行驶的车辆都易造成超薄沥青磨耗层的剪切破坏.当SBS掺量为4.0%～4.5%、补强剂掺量为0.30%～0.50%时,超薄沥青磨耗层能兼顾抗剪性能和其他路用性能,同时满足经济性.

The effects of raw material parameters and experimental conditions on shear strength of asphalt mixture were investigated based on uniaxial penetrating test and unconfined compressive test. The effects of SBS dosage, reinforcing agent dosage and gradation type on high temperature stability, low temperature crack resistance, water stability and anti-stripping performance of asphalt mixture were discussed by laboratory experiments. The results show that the shear property of skeleton structure is better than that of suspended dense structure, and the shear property of SBS modified asphalt mixture is better than that of matrix asphalt mixture. The shear strength of asphalt mixture with optimum asphalt content is large, and reinforcing agent can improve the shear property of mixture effectively. High temperature condition and running vehicle at low speed easily cause the shear failure of ultra-thin asphalt wearing course. When SBS dosage and reinforcing agent dosage are respective 4.0% to 4.5% and 0.30% to 0.50%, the ultra- thin asphalt wearing course can meet the requirements of shear property, other pavement performance and econonly.