基于动水冲刷试验的温拌高黏沥青混合料水稳定性研究

Water Stability of Warm-Mix High Viscosity Asphalt Mixture Based on Dynamic Water Scour Test

本文对排水沥青路面水稳定性进行研究,通过浸水马歇尔稳定度试验、肯塔堡飞散试验和冻融劈裂试验对比分析高黏沥青和两种温拌高黏沥青混合料的水稳定性,并引入高精度河流动力学水槽试验系统,设计冻融循环-动水冲刷-劈裂耦合试验,研究温拌高黏沥青混合料的水稳定性,在不同冲刷高度、冲刷速度和冲刷时间下对三种OGFC-13型高黏沥青混合料的质量损失率和劈裂强度比进行研究。试验结果表明:高黏沥青混合料残留稳定度有超100%的现象,三种沥青混合料浸水飞散损失量均在11%以下,且冻融劈裂强度比在95%以上,试验结果无明显差异,现行试验方法无法有效评价温拌高黏沥青混合料的水稳定性;冻融循环-动水冲刷-劈裂耦合试验中,冲刷速度和时间对高黏沥青混合料水稳定性影响最大,冲刷3 d后质量损失率可达4%,经30 L/s的速度冲刷后,高黏沥青混合料的质量损失率超过5%,劈裂强度比降至85%以下;温拌高黏沥青混合料的水稳定性可采用冻融循环-动水冲刷-劈裂耦合试验进行评价。

This article focused on the water stability of drained asphalt pavement.The water stability of high viscosity asphalt and warm-mix high viscosity asphalt mixtures were compared and analyzed through the immersion stability test,the Cantabro test and the freeze-thaw splitting test.A high-precision river dynamics flume test system was introduced in the research.A freeze-thaw cycle-dynamic water scour-splitting coupling test was designed to study the water stability of warm-mixed high viscosity asphalt mixtures.The mass loss rate and splitting strength ratio of three kinds of OGFC-13 high viscosity asphalt mixtures were studied under different scouring heights,scouring speeds and scouring time.The results show that the residual stability of high viscosity asphalt mixture exceeds 100%.The results of the dispersion loss of three kinds of asphalt mixtures are below 11%,and the freeze-thaw splitting strength ratio is above 95%.There is no significant difference among the test results,so the existing standard methods cannot effectively evaluate the water stability of the warm-mix high viscosity asphalt mixture.In the freeze-thaw cycle-dynamic water scour-splitting coupling test,the speed and time of scouring have the greatest impact on the water stability of the high viscosity asphalt mixture.The mass loss rate reaches 4%after 3 d of scouring and exceeds 5%after scouring at a speed of 30 L/s,and the splitting strength ratio drops below 85%at the same time.The water stability of the warm-mix high viscosity asphalt mixture can be evaluated by the freeze-thaw cycle-dynamic water scour-splitting coupling test.