【作者】 张兰峰；

【导师】 郝培文；

【作者基本信息】 长安大学 ， 材料学， 2008， 硕士

【摘要】 Top-down裂缝是柔性基层沥青路面常出现的破坏形式,其原因主要是由于重复交通荷载及低温应力引起的,被认为是和反射裂缝一样可能导致沥青路面承载力丧失的新型早期损坏。裂缝问题不仅是路面结构设计的问题,而且是材料设计的问题,为了防止裂缝发生,混合料就需要有更大的抗拉强度。本文主要针对沥青混合料各组成材料对抗裂性的影响进行研究。主要研究沥青用量、级配、沥青种类对top-down裂缝形成和扩展的影响。本文引入耗散蠕变应变能界限DCSE HMA作为判断沥青混合料开裂条件。研究基于沥青混合料IDT试验结果,将级配、沥青性质、集料特性等一些反映沥青混合料结构的影响因素包括在DCSE HMA中。针对每种沥青混合料分别进行25℃IDT抗拉试验,确定不同沥青混合料的抗拉强度和断裂能密度;进行25℃重复间接拉伸回弹模量试验,确定各沥青混合料的动态回弹模量和耗散蠕变应变能界限DCSE HMA;以及25℃间接拉伸蠕变试验,确定沥青混合料的蠕变柔量、沥青混合料开裂需要的DCSEmin和能量比ER= DCSE HMA/DCSEmin ,ER是确定沥青混合料是否发生开裂标准之一。最后本文对各沥青混合料进行25℃劈裂疲劳试验,验证了DCSE HMA作为沥青混合料抗裂性能评价指标的正确性。更多还原

【Abstract】 Top-down cracks is a sort of pavement failures, the major causes of leading top-down cracks are repeat traffic loads and low temperature stress. Top-down cracks having been considered as reflect cracks can result in asphalt pavement losting bearing capacity.Cracks is a matter of not only pavement structural design, more is materials designed matter.In order to avoiding cracking ,asphalt mixture demand greater tensile strength.This article aims at analyzing influence of crack resistance constructional materials of asphalt mixture.Mainly researchig influence of materials such as aspalt dosage、gradation、asphalt catalogue to top-down cracks formed and extended.Adopting AC-16 upper、middle、lower limit as test gradation ,Zhong hai 90# body asphalt、SBS modified asphalt、TPS modified asphalt as asphalt binder of mixture.This article introduce into dissipation creep strain energy limit(DCSEHMA),to analyze asphalt mixture cracking mechanism.This research based on asphalt mixture indirect tension test, DCSEHMA reflect properties of asphalt mixture,such as gradation、asphalt property、aggregate characteristics and so on. All kinds of asphalt mixtures are proceeded 25℃indirect tension test, ascertaining tensile strength and fracture energy density of different asphalt mixture.This article carried out resilient modulus of asphalt mixtures by indirect tension test at 25℃,to determine dynamic resilience modulus and DCSEHMA.Carrying out indirect tensile creep test at 25℃, to determine creep compliance、DCSEmin (asphalt mixture cracking requires minimum dissipation creep strain energy) and energy ratio ER= DCSEHMA /DCSEmin.ER is criteria to determine whether asphalt mixture can be crack and thichness of asphalt pavement. Finally,carrying out split fatigue test at 25℃for each asphalt mixture,to demonstrate whether DCSEHMA acting as asphalt mixture crack resistance indicator is validity .更多还原