ATB-30骨架密实级配与性能验证

ATB-30 Dense Skeleton Gradation and Performance Verification

为了提出ATB-30混合料骨架密实级配,分别采用马歇尔成型方法与垂直振动成型方法成型试件,基于i法,以i值对应沥青砂浆劈裂强度、抗剪强度最优为原则提出细集料级配,根据课题组已有成果提出粗集料级配、粗细比,拟定5组级配,通过力学强度与抗离析性能验证提出ATB-30骨架密实级配。结果表明:i为0.75时细集料级配最佳;粗细集料比例为67∶33、70∶30、73∶27时ATB-30混合料马歇尔稳定度、劈裂强度、抗剪强度分别为规范级配中值的1.20~1.27倍、1.06~1.13倍和1.18~1.31倍。试验段芯样的检测结果表明振动法成型与现场的相关性更高,建议采用振动法成型试件以评价大粒径沥青混合料的路用性能。在力学强度与抗离析性能均满足条件的基础上,提出ATB-30混合料骨架密实级配。

In order to propose ATB-30 dense skeleton gradation,the Marshall compaction method and vertical vibration compaction method are applied to prepare specimens.Based on the i method,fine aggregate grading is proposed based on the principle that the value of i corresponds to the optimal splitting strength and shear strength of asphalt mortar.According to the existing achievements of the research group,the coarse aggregate grading and thickness ratio are proposed,and five groups of gradation are put forward.The gradation is proposed through the verification of mechanical strength and anti-segregation performance.The results show that:when the i value is 0.75,the mechanical properties of fine aggregate gradation are the best;when the ratio of coarse and fine aggregate is 67∶33,70∶30 and 73∶27,the Marshall stability,splitting strength and shear strength of ATB-30 mixture are 1.20~1.27 times,1.06~1.13 times and 1.18~1.31 times of the standard grading median,respectively.The test shows that the vibration method is more relevant to the field.It is suggested to use the vibration method to form the test piece to evaluate the road performance of asphalt mixture with large particle size.On the basis of satisfying the mechanical strength and segregation resistance,the compactness gradation of ATB-30 composite skeleton is proposed.