透水聚酯纤维沥青混合料动力学特性研究

Study on Dynamic Characteristics of Permeable Polyester Fiber Asphalt Mixture

聚酯纤维透水沥青混合料是国内透水沥青路面材料的主要研究方向。目前相关研究主要集中在聚酯纤维透水沥青混合料静态、准静态条件下的力学性能研究,缺少冲击、撞击作用下的动态性能分析。该研究通过SHPB试验系统,成型试件后开展冲击压缩试验与劈裂试验,分析了混合料的动力学特性及规律。结果表明:(1)混合料存在明显的冲击抗压强度应变率效应,属于应变率敏感性材料,冲击抗压强度随应变率增大而提高;冲击压缩应力-应变曲线分为弹性变形、塑性变形、破坏三个阶段。(2)冲击劈裂强度随着冲击气压的增大而增大;(3)聚酯纤维的掺入可以显著提升透水沥青混合料的动力学特性,最佳掺量为0.4%,过量掺入会导致混合料抗劈裂强度下降;(4)集料断裂是聚酯纤维透水沥青混合料动态破坏的重要原因。

Polyester fiber permeable asphalt mixture is the main research direction of permeable asphalt pavement materials in China.At present,relevant researches mainly focus on the mechanical properties of polyester fiber permeable asphalt mixture under static and quasi-static conditions,but lack of dynamic properties analysis under impact.Therefore,in this paper,the impact compression test and splitting test were carried out after forming the specimen through the SHPB test system,and the dynamic characteristics and rules of the mixture were analyzed.The following conclusions were drawn:(1)The mixture has an obvious impact compressive strength strain rate eff ect,which is a strain rate-sensitive material.The impact compressive strength increases with the increase of strain rate;The stress-strain curve of impact compression can be divided into three stages:elastic deformation,plastic deformation and failure.(2)The impact splitting strength increases with the increase of impact pressure;(3)The addition of polyester fiber can significantly improve the dynamic characteristics of the permeable asphalt mixture,and the optimal content is 0.4%.Excessive addition will lead to the decrease of the anti-splitting strength of the mixture.(4)Aggregate fracture is an important cause of dynamic failure of polyester fiber permeable asphalt mixture.