相变材料对温拌沥青混合料路用性能及微观机理的影响

为研究相变材料DTC对温拌沥青混合料路用性能的影响，通过马歇尔稳定度试验、冻融劈裂试验、小梁弯曲试验、电子显微镜试验以及核磁共振试验，研究了不同DTC掺量下相变温拌沥青混合料的高温、低温、水稳性能的影响规律及其微观机理。结果表明：马歇尔稳定度值、小梁抗弯拉强度值与DTC掺量符合线性关系，通过t检验和F检验可知，短期老化对劈裂抗拉强度比的均值和方差无显著影响，长期老化对劈裂抗拉强度比的均值影响显著，对方差无显著影响。电子显微镜和核磁共振的研究发现：随着DTC掺量的增多，试件内的孔隙越来越多，但孔径分布及其峰值主要集中在0.01um-1um之间，孔隙度也在增大，这也正是DTC掺量越大，马歇尔稳定度值、劈裂抗拉强度值和小梁抗弯拉强度值下降越多的主要原因。通过灰色关联度分析获知，老化对沥青混合料路用性能的关联度影响甚微。因此，DTC掺量对沥青混合料的路用性能影响由大到小依次是马歇尔稳定度、抗弯拉强度、劈裂强度；相关性分析表明，沥青混合料微观结构特性与其宏观性能的相关系数都在0.77以上，宏细观性能紧密关联。

Influence of Phase Change Materials on Road Performance and Micro Mechanism of Warm mix Asphalt Mixture

In order to study the effect of phase change material DTC on the road performance of warm mix asphalt mixture, the high-temperature performance, low-temperature performance, water-stability performance and microscopic mechanism of the phase change warm mix asphalt mixtures with different DTC dosage were studied by Marshall stability test, freeze-thaw splitting test, trabecular bending test, electron microscope test and nuclear magnetic resonance test. The results show that Marshall''s stability value and the flexural tensile strength value of trabecular are linear with DTC dosage. Through t test and F test, it can be seen that short-term ageing has no significant impact on the mean and variance of split tensile strength ratio, but long-term ageing has significant impact on the mean of the tensile strength ratio of splitting, and there is no significant impact on its variance. The study of electron microscope and nuclear magnetic resonance shows that there are more and more pores in the specimens with the increase of DTC dosage, but the pore distribution and peak are mainly concentrated between 0.01um-1um, and the porosity is also increasing. This is also the main reason why the greater the DTC dosage, the more decreasing of the Marshall''s stability value, split tensile strength value and the flexural tensile strength value of trabecular. Through grey correlation analysis, it is learned that ageing has little impact on the correlation degree of road performance of asphalt mixture. Therefore, the influence of DTC dosage on asphalt mixture is Marshall''s stability, flexural tensile strength value of trabecular and splitting strength in the descending order. Correlation analysis shows that the correlation coefficient between the microstructure characteristics of asphalt mixture and its macroscopic properties is more than 0.77, so the macro and meso properties are closely related.