TLA改性沥青及其混合料氯盐侵蚀下的性能研究

Study on the Performance of TLA Modified Asphalt and Its Mixture Under Chloride Erosion

为研究基质沥青及特立尼达湖沥青(TLA)改性沥青及其混合料在不同浓度和不同侵蚀时间的盐雾试验作用后性能的变化,通过沥青三大指标试验对两种沥青盐雾侵蚀的性能指标进行分析,然后通过浸水马歇尔试验和冻融劈裂试验对盐雾侵蚀后的两种沥青混合料水稳定性进行研究。结果表明,随着氯盐浓度的增大或作用时间的增长,两种沥青的针入度、延度减小,软化点上升,TLA的掺入可一定程度减小氯盐对基质沥青的侵蚀作用;随着氯盐浓度的增大或作用时间的增长,两种沥青混合料的稳定度、劈裂强度呈现线性递减的趋势,流值逐渐变大,与作用时间相比,浓度变化对稳定度的影响更大;TLA改性沥青混合料的冻融劈裂强度比大于基质沥青,且变化程度较小,TLA改性沥青的掺入可提高沥青混合料的水稳定性,更能抵抗氯盐盐雾侵蚀,具有更好的耐腐蚀性。沥青混合料的稳定度、流值、劈裂强度与氯盐浓度和作用时间呈线性相关的关系。

In order to study the change of properties of matrix asphalt, TLA modified asphalt and their mixtures after salt spray test with different concentration and different erosion time, the performance indexes of two kinds of asphalt salt spray erosion were analyzed through three indexes of asphalt, and then the water stability of two kinds of asphalt mixtures after salt spray erosion was studied through immersion Marshall test and freeze-thaw splitting test. The results show that with the increase of chloride concentration or the increase of action time, the penetration and elongation of the two bitumen decrease, and the softening point increases. The addition of TLA can reduce the erosion effect of chloride on the matrix bitumen to some extent. With the increase of chloride concentration or the increase of action time, the stability and splitting strength of the two asphalt mixtures show a linear decreasing trend, and the flow value will gradually increase. Compared with the action time, the change of concentration has a greater influence on the stability. The ratio of freeze-thaw splitting strength of TLA modified asphalt mixture is higher than that of base asphalt, and the change degree is small. The addition of TLA modified asphalt can improve the water stability of asphalt mixture, and better resist the erosion of chlorine salt spray, and has better corrosion resistance. The stability, flow value and splitting strength of asphalt mixture are linearly related to chloride concentration and action time.