动水冲刷加速沥青混合料水损坏规律研究

Study on the law of dynamic water scouring to acceleratemoisture damage of asphalt mixture

文章研究动水冲刷加速沥青混合料水损坏的规律,设计了长时间浸水的沥青混合料试件的冻融劈裂试验和SMA-13的动水冲刷试验。研究结果表明,静水浸泡试验冻融劈裂强度比(tensile strength ratio,TSR)随浸泡时间的增加而降低,动水冲刷试验TSR随动水压力的增大、冲刷次数的增加而不断降低;冲刷32400次比冲刷10800次的TSR降低约9%,与静水浸泡3个月后的TSR降幅非常接近;动水冲刷可以在短时间内使沥青混合料水损坏达到在静态水长期浸泡下的程度,0.1 MPa压力下冲刷21600次的水损坏效果与浸水3个月的相近。

In order to probe the law of dynamic water scouring to accelerate the moisture damage of asphalt mixture,two kinds of asphalt specimens were processed.Some specimens were soaked for a long time after vacuum saturation and then split after freeze-thaw cycle.The freeze-thaw splitting test on the other specimens was also carried out after dynamic water scouring.The test results show that the tensile strength ratio(TSR)in hydrostatic immersion test decreased with the increasing immersion time.The TSR in dynamic water scouring experiment decreased with the increases of the dynamic water pressure and the erosion time.When the specimens were scoured from 10800 times to 32400 times,its TSR value decreased about 9%,which is very close to the TSR variation for asphalt specimens soaked for three months.Dynamic water scouring can make the moisture damage of asphalt mixture reach the degree of long-term immersion in the static water in a short period of time.The moisture damage effect of asphalt mixture with 21600 times of scouring under 0.1 MPa pressure is similar to that of three months of immersion.