Strength improvement of cement emulsified asphalt mixture through aggregate gradation design

摘要

Aggregate gradation greatly affects properties of cement emulsified asphalt mixture (CEAM). In this work, an aggregate design based on fractal theory method (FTM) was put forward and trial calculation method (TCM) was adopted to design aggregate gradation of the mixtures. Properties of the mixtures, Marshall stability and splitting strength, were adopted as indexes to evaluate effects of the two methods. In addi-tion, other properties of the mixtures such as, voids in mineral aggregates, porosity and residual stability of the mixtures were carried out to verify effects of the two methods. Furthermore, the gradation obtained by the two methods was simulated based on partical flow code in two dimension (PFC2D). The results show that the aggregate with the optimum gradation possesses dense skeleton structure and excellent stability. Particle contact force is relatively uniform distribution. Besides, voids in the min-eral aggregate, porosity and residual stability of the mixture designed by FTM were superior to that designed by TCM. It was confirmed that the aggregate gradation design method with fractal model estab-lished in this work is reasonable and effective to improve strength of cement emulsified asphalt mixture. (c) 2021 Elsevier Ltd. All rights reserved.