沥青混合料浸水马歇尔试验方法改进研究

Research on Improving Immersed Marshall Test Method for Asphalt Mixture

针对沥青混合料浸水残留稳定度超100%的现象,开展了改性沥青和基质沥青在水浴(60℃、48h)和空气浴(60℃、48h)中的老化试验研究,并提出了改进的浸水马歇尔试验方法。结果表明:沥青在水浴和空气浴条件下老化程度排序为:短期老化>空气浴老化>水浴老化>原样;现有的浸水马歇尔试验无法排除沥青老化对稳定度的影响,造成残留稳定度经常超过100%,试验结果失真,无法客观评价混合料水稳定性;改进的浸水马歇尔试验采用稳定度损失率来评价水损害程度,指标含义明确,对不同类型的混合料均适用。

For Over 100%residual stability of asphalt mixture,aging test research has been carried out on the modified asphalt and matrix asphalt in water bath(60℃,48 h)and air bath(60℃,48 h).The improvement method of Marshall immersion test has been proposed.Result has shown that the aging degree of asphalt in water bath and air bath is ranked as follows:short-term aging>air bath aging>water bath aging>original sample;the existing immersion Marshall test cannot exclude the influence of asphalt aging on stability,resulting in residual stability often exceeding 100%,and the test result is distorted and impossible to objectively evaluate the water stability of mixture.The improved immersion Marshall test adopts stability loss rate to evaluate water damage degree.The index has a clear meaning and could be applied to different types of mixtures.