半刚性基层沥青路面层间处治增强黏结力的试验

Test on strengthening interlayer cohesion of semi-rigid base asphalt pavement by interlayer treatment

为提高半刚性沥青路面中水泥稳定碎石基层和沥青层的层间黏结力,提出一种在半刚性水泥稳定碎石基层表面引入规则凹坑的层间处治新方法。采用标准尺寸的模具结合静压成型法,成型具有规则凹坑的基层表面,再整体成型半刚性基层沥青路面,采用剪应力和拉拔应力测试设备对试验样本进行最大应力测试,并对半刚性水泥稳定碎石基层处治凹坑后成型的沥青路面与传统的层间处治方法进行比较。研究结果表明:所设计的成型方法能高效成型表面有规则凹坑的半刚性基层及半刚性基层沥青路面。处治9个直径18 mm(Φ18)凹坑的路面层间最大剪应力比精铣刨工艺时所受剪应力提高5.2%,最大拉拔力提高7.39%;比喷洒透油层时最大剪应力提高41.05%,最大拉拔力提高29.51%;比未处治时最大剪应力提高71.65%,最大拉拔力提高80.38%。路面处治12个凹坑的最大剪应力比4个凹坑时提高22.72%,最大拉拔力提高23.2%;9个Ф18凹坑比9个Ф8凹坑承受的层间最大剪应力增加43.4%,最大拉拔力增加35.87%,增加凹坑的尺寸和个数均可等效于增加了其摩擦因数和铆锁抵抗力,具有提高力学性能的效果。当路面的环境温度变化时,采用凹坑处治的路面承受的层间最大剪应力变化最小,增强了环境变化下抗疲劳强度能力。与传统的层间处治方法相比,通过对半刚性水泥稳定碎石基层处治凹坑后成型的沥青路面能有效提高路面在外载荷下的抗剪强度、抗拉拔强度及抗疲劳强度能力,该方法可为半刚性基层层间工程化处治提供借鉴。

In order to improve the interlayer cohesion between cement stabilized macadam and asphalt layer in semi-rigid asphalt pavement,a new method of interlayer treatment by introducing regular pits on the surface of semi-rigid cement stabilized macadam base course was proposed.The standard size die combined with hydrostatic forming method was used to form the regular pits on base course,and the semi-rigid base asphalt pavement was finally formed by the die integration.The stress properties of the samples were tested by shear stress and pulling stress equipment,then the new treatment methods and traditional treatment methods were compared.The results show that the designed forming method can effectively form semi-rigid cement stabilized macadam base and semi-rigid base asphalt pavement with regular pits on the surface.The maximum interlayer shear stress of the pavement with 9 pits of diameter is 18 mm(Ф18)on the base is 5.2%higher than that of the milling process,and the maximum pulling stress is increased by 7.39%.The maximum interlayer shear stress is 41.05%higher than the base course with oil permeable layer,and the maximum pulling stress is increased by 29.51%.The maximum interlayer shear stress is 71.65%higher than that of the untreated base course,and the maximum pulling stress is increased by 80.38%.The maximum shear force of the base course with 12 pits is 22.72%higher than that of 4 pits,and the maximum pulling force is increased by 23.2%,the maximum interlayer shear force of the base course with 9 pits ofФ18 mm is 43.4%higher than that of 9 pits ofФ8 mm,and the maximum pulling stress is increased by 35.87%.Increasing size and number is equivalent to increasing friction coefficient and rivet resistance,which can improve mechanical property efficiency.With the change of the pavement temperature,the maximum shear force of the pavement treated with pits changes little,which enhances the fatigue strength of the pavement.Compared with the traditional interlayer treatment method,the semi-rigid cement stabilized macadam base treated by pits can effectively improve the shear strength,pulling strength and fatigue strength of the pavement under external loads.This method can provides a reference for engineering treatment of the base course.4 tabs,7 figs,25 refs.