沥青混合料水稳定性评价方法研究

马歇尔试件成型时采用不同击实次数,使试件空隙率控制在5 %～6 %这一抗水损害最不利状态下,并分别进行了浸水马歇尔试验、真空饱水马歇尔试验和冻融劈裂试验.研究表明,浸水马歇尔试验和真空饱水马歇尔试验无法模拟实际路面上空隙水受行车荷载作用对沥青膜的挤压破坏作用,不能准确地评价沥青混合料的水稳定性.而真空饱水率与冻融劈裂强度比之间存在良好的相关性,在饱水率为1.5 %～2.0 %时进行冻融劈裂试验可以较好的模拟沥青路面空隙水的存在状态和受力情况.因此,采用合理饱水率范围内冻融劈裂强度比来评价沥青混合料的水稳定性将更加可靠.

Study on the Immersion Stability of Asphalt Mixture

By different hitting times, air voids of Marshall specimens should be most disadvantageous to water damage between 5 % and 6 % for immersion Marshall test, vacuum water-saturated Marshall test and freez-thraw split test. The study shows that Percentage of vacuum water-saturated is well relative to freez-thraw split strength ratio. However, the freez-thraw split test can simulate preferably compression-damage function of traffic load to void water in pavement and evaluate the water stability of asphalt mixture when water-saturated rate is between 1.5 % and 2.0 % instead of the immersion Marshall test and vacuum water-saturated Marshall test. So, it is more reliable to evaluate the water stability of and reasonable range for water-staturated rate. asphalt mixture in freez-thraw split strength ratio