论文部分内容阅读
布敦岩天然沥青(BRA)兼具性能和经济优势,为了研究BRA的路用性能,首先采用针入度等级评价方法对不同掺量的BRA改性沥青进行性能评价,其次结合长安街辅路大修工程利用车辙试验、浸水马歇尔试验、冻融劈裂试验及小梁低温弯曲试验对BRA改性沥青混合料路用性能进行试验研究。研究表明:BRA能有效改善沥青的高温性能、感温性能和抗老化性能,大大提高混合料的高温稳定性和水稳定性,而低温性能略有降低;BRA掺量不易超过30%,推荐掺量范围25%～30%,典型掺量30%。相关性研究表明:针入度、软化点、当量软化点与动稳定度相关性系数均在0.9左右,相关性良好,能有效评价BRA改性沥青的高温性能;延度指标不适于评价BRA改性沥青的低温性能;当量脆点、测力延度试验柔度系数与破坏应变相关系数分别达0.9643和0.9545,是BRA改性沥青低温性能的有效评价指标,且为保证混合料低温性能满足规范要求柔度系数应不大于412.6N/cm。
In order to study the road performance of BRA, Bourdon rock natural bitumen (BRA) has both performance and economic advantages. Firstly, the evaluation method of penetration degree is used to evaluate the performance of BRA modified bitumen. Secondly, The rutting test, immersion Marshall test, freeze-thaw splitting test and trabecular low temperature bending test were used to test the road performance of BRA modified asphalt mixture. The results show that: BRA can effectively improve the high temperature performance, temperature performance and anti-aging performance of asphalt, greatly improve the high temperature stability and water stability of the mixture, while the low temperature performance slightly decreases; BRA dosage is not easy to exceed 30% The amount of 25% to 30%, a typical content of 30%. Correlation studies show that: the correlation coefficient of penetration, softening point, equivalent softening point and dynamic stability are about 0.9, the correlation is good, can effectively evaluate the high temperature properties of BRA modified asphalt; ductility index is not suitable for the evaluation of BRA change Low temperature performance of asphalt asphalts; the correlation coefficients of equivalent ductility, ductility and failure strain of equivalent brittle point and test ductility test are 0.9643 and 0.9545, respectively, which are effective evaluation indexes of low temperature performance of BRA modified asphalt. In order to ensure low temperature performance of the mixture, The compliance factor should not be greater than 412.6N / cm.