液体沥青混合料强度生成规律研究及性能优化

In order to improve the service life of cutback asphalt mixture pavement,the generation law of its splitting tensile strength and the method of performance optimization were explored. The changes of functional groups of cutback asphalt before and after curing at 110 ℃ were identified by Fourier transform infrared spectroscopy to determine the cohesive force mechanism of asphalt. And based on the generalized time-temperature equivalence principle,the splitting tensile strength growth models of two graded mixtures are studied. According to the characteristics of cutback asphalt mixture,the corresponding performance evaluation methods and indicators are put forward. Finally, the performance optimization scheme is proposed from the two aspects of filler and admixture. The results show that the essence of improving the cohesive force of cutback asphalt is the physical process of the volatilization of diluent components, and the Sigmoidal model can reflect the generation law of the splitting tensile strength of cutback asphalt mixture. In addition, compared with AC gradation, LB gradation has better performance. However, the two graded mixtures have the problems of poor water stability and insufficient initial strength. The performance can be optimized by adding cement:mineral powder = 3∶ 7 composite filler and 3% polymerized MDI. In general,the initial strength and water stability of LB-16 graded liquid asphalt mixture can meet the requirements after adding cement and polymeric MDI.