旧料掺量对温拌再生沥青混合料耐久性的影响分析
Influence of RAP content on durability of warm mix recycled asphalt mixture

为了研究旧料掺量对温拌再生沥青混合料耐久性的影响，采用冻融劈裂与水损坏敏感试验（MIST）研究混合料抗水损害性能，采用半圆弯曲试验研究混合料抗裂性能，采用标准贯入试验（SPT）研究混合料动态模型变化趋势。结果表明：随着回收沥青路面材料（RAP）含量的增加，水处理后沥青混合料弹性模量比逐渐提高，水对弹性模量的衰减程度影响相对较低；混合料破坏时的耗散徐变应变能DCSE？？f先增加后减少，温拌再生沥青混合料中存在一个最佳的RAP含量；旧料的增加在一定程度上降低了沥青混合料的抗开裂能力，使混合料向脆化方向发展，当旧料掺量达到一定水平后，再生沥青混凝土的抗裂性能将不再降低；同等条件下，RAP掺量越大，再生混合料动态模量越大，混合料表现出更多的刚性，更趋于脆性，随着试验温度的提升，温拌再生沥青混合料的动态模量更多地显现出黏弹性特征；相同RAP含量时，热再生沥青混合料浸水后抗变形能力、抗裂能力及动态模量均高于同等条件下的温拌再生混合料；热再生条件下能融化RAP料表面旧沥青的数量比温拌条件时多，使混合料更密实，其体积特征的变化带来了性能的差异。
To study the effect of old material content on durability of warm？？mix recycled asphalt mixture, the water resistance performance of mixtures were studied by freeze？？thaw splitting test and moisture？？induced sensitivity test (MIST), the anti？？cracking performance of asphalt mixtures were studied by semi？？circular bending test，the change trend of the dynamic modulus of the mixture.were studied by simple performance tester (SPT). The results show that, with an increase in recycled asphalt product (RAP) content, the dynamic modulus ratio of the asphalt mixture increases gradually after water treatment, the influence attenuation of water to the dynamic modulus is relatively low. The dissipated creep strain energy (DCSE？？f) of the warm？？mixed asphalt first increases and then decreases. an optimum RAP content in warm mix recycled asphalt mixture. There is an increase in RAP reduces the anti？？cracking ability of the asphalt mixture to a certain extent and causes the mixture to develop brittleness. When the RAP content reaches a certain level, the cracking resistance performance of the recycled asphalt is no longer reduced. Under the same conditions, the greater the RAP content, the greater the dynamic modulus of the regenerated mixture, the greater the stiffness, and the more brittle the mixture. With an increase in test temperature, the dynamic modulus of the warm？？mixed asphalt shows more viscoelastic characteristics. In a comparison between hot？？mixed and warm？？mixed asphalts with the same RAP content, the resistance to deformation, crack resistance, and dynamic modulus of the hot recycled asphalt mixture were higher than those under similar conditions. Under the condition of hot regeneration, The amount of old asphalt that RAP material is more than that of warm mix, under conditions of thermal regeneration. The higher density of the mixture and the change in volume characteristics lead to differences in performance. 4 tabs, ？？4 figs？？, 23 refs.？