超声波测试方法在沥青混合料冻融试验中的应用

基于超声波传播原理,将超声波测试方法引入到沥青混合料的冻融试验中.通过对试验结果的分析,讨论了试验数据离散性较大的原因,提出了影响超声波测试方法精度的多重因素;进而基于微观结构分析对试验数据提出了合理的修正方法,并推荐了超声波测试方法在沥青混合料冻融试验中应用的经验公式;最后通过对比试验验证了经验公式形式的正确性.结果表明,修正后的超声波传播速度能表征沥青混合料冻融后的劈裂强度,两者之间有着很好的指数关系.

Application of Ultrasonic Test Method in Freeze-thaw Test of Asphalt Mixture

First, based on the principle of ultrasonic propagation, the ultrasonic test method was introduced in freeze-thaw test of asphalt mixture.Through the analysis of test result, the reasons of obvious dispersion of test data were discussed, and the multiple factors of influencing precision of ultrasonic test method were presented.Then a reasonable modified method to test data was proposed based on analysis to microstructure, and the empirical formula for ultrasonic test method in freeze - thaw test of asphalt mixture was recommended.At last, the validity of the empirical formula was validated through contrast test.The result shows that (1) the modified ultrasonic propagation velocity can be used to characterize the splitting strength of asphalt mixture after freeze-thaw cycles; (2) there are good exponential relationships between the velocity and strength.