OLSM-25防裂层沥青路面疲劳寿命与抗裂机理研究

Research on Fatigue Life and Anti- cracking Mechanism of Open- graded Large Stone Asphalt Mixes （OLSM -25 ） Anti- Cracking Layer in Asphalt Pavement

为了解决刚性基层沥青路面存在的沥青面层反射裂缝问题，提出了采用开级配大粒径沥青碎石混合料（Open—graded Large Stone Asphalt Mixes，OLSM）作为裂缝缓解层的方法，以国内外OLSM参考级配为基础，结合试验段修筑情况，采用二维有限元方法，建立设置OLSM-25裂缝缓解层的沥青路面有限元模型，对设置不同类型裂缝缓解层、不同级配OLSM-25裂缝缓解层的沥青路面进行疲劳分析，从宏观力学响应方面阐释了OLSM-25裂缝缓解层的抗裂机理。结果表明：在车辆荷载偏载作用下，与相同厚度的普通AC-25裂缝缓解层相比。采用OLSM-25裂缝缓解层可有效减缓基层裂缝的扩展速率，显著提高沥青路面结构的疲劳寿命，OLSM-25裂缝缓解层的抗裂效果优于普通AC-25裂缝缓解层。

In order to solve the problem of the reflective cracking in the rigid base asphalt pavement, a method of using Open - graded Large Stone asphalt Mixes （OLSM） as the crack relief layer is proposed. On the basis of the reference gradation of OLSM in the domestic and international, combined with the test roads construction, by u- sing of two - dimensional finite element method, the finite element model of asphalt pavement structure with OLSM -25 cracking relief layer has been established, fatigue analysis on asphalt pavement with two different types of cracking relief layer, and three different gradations OLSM - 25 cracking relief layer have been carried out, and the anti - crack mechanism of OLSM - 25 cracking relief layer has been illustrated from the aspects of macro mechani- cal response. The result indicates that as follows： Under the action of the asymmetric traffic load, compared to the ordinary AC - 25 cracking relief layer with the same thickness, by using the cracking relief layer of OLSM - 25, the propagating speed of the reflective crack will be slow down effectively, and the fatigue life of the asphalt pavement structure will be improved significantly, and the anti - cracking effect of OLSM - 25 cracking relief layer is better than that of ordinary AC -25 cracking relief layer.