【摘要】 以橡胶沥青再生混合料为研究对象,对冻融前后的小梁试件分别进行低温弯曲试验,研究不同胶粉掺量(6.4%,9.2%和14.1%)、不同胶粉细度(20目,40目和80目)和不同RAP掺量(25%,35%和50%)条件下的橡胶热再生沥青混合料的低温性能.基于工业CT无损检测技术,对冻融前后的橡胶热再生混合料试件分别进行扫描,并定量表征冻融前后试件体积指标的变化.研究结果表明:RAP掺量为25%,胶粉细度为80目,胶粉掺量为9.2%的橡胶热再生沥青混合料冻融后的低温性能下降幅度最小;相较于基质沥青热再生混合料,橡胶沥青热再生沥青混合料具有更好的耐久性及低温性能;通过对比工业CT扫描结果发现,冻融后的橡胶热再生沥青混合料试件闭口空隙率增大了20.3%,且在0~25mm3体积范围内的空隙数量减少了13.8%,在25~50 mm3体积范围内的空隙数量则增加了62.9%.更多还原

【Abstract】 This paper took rubber recycled asphalt mixture as research objects,and the low temperature bending test was conducted on small specimen beams before and after freezing-thawing process separately.The low temperature performances of rubber hot recycled asphalt mixture with different rubber powder dosages(6.4%,9.2%and 14.1%),rubber powder sizes(20mesh,40 mesh and 80mesh)and RAP dosages(25%,35%and 50%)were studied.The specimens were scanned before and after freezing-thawing process based on industrial computer tomography(CT)nondestructive testing,separately,and the quantitative analysis for the volume index of specimens was presented.The result shows that the low temperature performance of rubber hot recycled asphalt mixture with 25% RAP,80 mesh rubber powder fineness and 9.2% rubber powder dosage after freezing-thawing process has the minimal decrease.Compared with hot recycled mixture with neat asphalt,the hot recycled asphalt mixture with crumb rubber asphalt has better durability and low temperature performance.By the comparison of different CT scanning results,the enclosed air void of specimens after freezing-thawing process increased by 20.3%,and the air void number has decreased by 13.8%in 0~25mm3 volume range and increased by 62.9%in 25~50mm3 volume range.更多还原