Cape路面荷载型反射裂缝的细观数值分析

Mesoscopic Numerical Analysis of Reflective Cracking in Cape Seal Pavement Under Load

用细观数值方法分析Cape路面抗反射裂缝性能的主要影响因素；利用有限元方法进行数值分析，材料参数根据试验数据利用最优化方法拟合得出.数值分析表明，Cape路面的沥青碎石采用较低的沥青含量时，其抗反射裂缝性能较好，而采用较低的空隙率时则有不利影响，但这种不利的影响程度并不大；基层裂缝附近的Cape路面与旧路面可脱开时，反射裂缝不易萌发与扩展，但脱开长度不宜过大；摊铺厚度较大时其抗反射裂缝性能较高，但综合考虑摊铺厚度不宜超过5-6 cm；较好的基层处理质量能减缓反射裂缝的扩展；采用半开级配的沥青碎石能够消散应力，减缓反射裂缝的萌发与扩展.

A mesoscopic numerical analysis was made with FEM for the main influencing factors on the resistance to the reflective cracking in Cape seal pavement under load,and the parameters of materials used were given through fitting optimization.The results showed that in Cape seal pavement the resistance to reflective cracking is high if the asphalt content is low in asphalt macadam,while low void has adverse effect though it is not great.The reflective crack is not easy to form and propagate when the pavement in the vicinity of bottom crack can be separating to a certain extent from the old pavement.The resistance to reflective cracking is high for thick pavement but,in view of an overall consideration,the paving thickness should not exceed 5～6 mm.The propagation of reflective cracking can be dampened if temping well the substrate of pavement,and the gap-graded asphalt macadam can decentralize the stress to dampen the formation and propagation of reflective cracking.