沥青混合料加铺层抗反射裂缝试验新方法优化研究

A new method for evaluation of anti-cracking performance of asphalt mixture overlay

采用OT(overlay tester)试验,从级配类型、沥青类型、拉伸位移、试验温度、试件厚度研究沥青混合料加铺层抗反射裂缝性能的问题。结果表明,试验温度25℃时,不同级配类型混合料裂缝发展和破坏不同,最终造成抗裂性能的差异;试验温度15℃时,沥青类型影响大于级配类型影响,其中KWG沥青最优;增加拉伸位移,抗裂性能急剧下降,应根据气候特点和材料类型进行选择;增加厚度可有效延缓反射裂缝的发展。OT试验适用于评价沥青混合料加铺层抗反射裂缝性能。

Since it was difficult to evaluate the anti-reflection crack performance of asphalt mixture overlay by using conventional method,the effects of gradation type,asphalt type,tensile displacement,test temperature and sample thickness on reflective cracking performance were evaluated by using the OT test.The result showed that different gradation types led to the different development and damage mode at 25℃,which would cause different anti-reflection crack performance.At 15 ℃,asphalt type has a higher impact on the anti-reflection performance than that of gradation type while KWG asphalt has be best performance.The anti-reflection crack performance decreased with the increase of tensile displacement.It was better to choose tensile displacement according to climatic characteristics and materials.The development of cracking could be delayed by the increase of thickness.It can be concluded that OT test can be used to evaluate anti-reflection crack performance of asphalt mixture overlay.