盐度对沥青混合料冻融劈裂试验影响研究

Research on Influence of Salinity on Freeze-thaw Split Test of Asphalt Mixtures

为研究沿海地区盐度对沥青混合料水稳定性能的影响,以普通沥青混合料与橡胶粉改性沥青混合料为研究对象,进行沥青混合料冻融劈裂试验。试验采用双面击实50次的标准马歇尔试块,分别放置在空气中、浸泡2 d介质与4 d介质3种条件,浸泡介质分别为10%盐水和清水。试验前,试块在-18℃的条件下冰冻24 h,然后在60℃的恒温水浴中浸泡24 h。试验结果表明:随着浸泡天数的增加,劈裂强度逐渐下降;浸泡盐水较清水冻融劈裂强度小,橡胶粉沥青混合料下降速度较缓。

In order to study the influences of salinity on moisture susceptibility of asphalt mixture, the freeze -thaw tests of normal asphalt mixtures and rubber modified asphalt mixtures were carried on. All Marshall specimens are made in accordance with the criterion of 50 beats on both sides. And then it was soaked in three different media： in the air, 2 d in salt water and fresh water, 3 d in salt water and fresh water. Before testing, the specimens are frozen 24 h at - 18 ℃, then are soaked in 60 ℃ temperature water bath. The results show that, with the times of immersion creasing, the split strength is deceasing, and the split strength of specimen soaked in salt water is smaller, the strength of mixtures using rubber modified asphalt decreasing slowly.