温拌再生沥青混合料二次老化性能研究

Study on Secondary Aging Performance of Warm Mix Recycled Asphalt Mixture

为研究温拌再生沥青混合料二次老化性能,通过高温车辙、低温弯曲、浸水马歇尔、冻融劈裂以及半圆弯曲疲劳等试验及对应参数对混合料进行路用性能评价。试验表明温拌再生技术提高了沥青混合料的高温性能,但RAP(Recycle Asphalt Pavement)的存在降低了温拌再生沥青混合料的低温性能、水稳定性和疲劳性能,可以通过添加SBR(Styrene-butadiene Rubber)改性剂弥补相应性能的损失。随着RAP掺量的增加,二次老化后的温拌再生沥青混合料性能衰减幅度远高于新沥青混合料。因此,不仅要关注温拌再生沥青混合料刚制备好时的性能,还要注意其二次老化后的性能,即使使用了外掺剂,还是要谨慎选择RAP的掺量。

In order to study the secondary aging performance of warm-mix recycled asphalt mixture,the pavement performance of the mixture was evaluated through high-temperature rutting,low-temperature bending,water immersion Marshall,freeze-thaw splitting,and semicircular bending fatigue tests and corresponding parameters.Tests have shown that warm mix regeneration technology improves the high temperature performance of asphalt mixture,but the presence of RAP(Recycle Asphalt Pavement)reduces the low temperature,water stability and fatigue performance of warm mix recycled asphalt mixture,which can be modified by adding SBR(Styrene-butadiene Rubber) to compensate for the loss of performance.With the increase of RAP content,the performance attenuation range of the warm mix recycled asphalt mixture after secondary aging is much higher than that of the new asphalt mixture.Therefore,we should not only pay attention to the performance of warm-mix recycled asphalt mixture when it is just prepared,but also pay attention to its performance after secondary aging.Even if an external admixture is used,the amount of RAP should be carefully selected.