Predicting the mechanical properties of semi-flexible pavement material with micromechanical modeling
Senlin Ling, Denis Jelagin, Manfred N. Partl, Daquan Sun, Hassan Fadil
Abstract
• The 3D representative volume element of semi-flexible pavement (SFP) material can accurately predict the uniaxial compressive strength and stiffness of SFP. • High-strength, low-modulus materials improve SFP mechanical properties by harmonizing cement and PA deformation. • The SFP properties can be improved by strengthening the interface properties, until a certain threshold value. • Aggregate modulus has no significant effect on the compressive properties of SFP, but higher modulus asphalt mortar significantly improve them. Semi-flexible pavement (SFP) material is a composite comprising cement, coarse aggregates and asphalt mortar, which has complex mechanical properties. Traditional experimental methods struggle to accurately quantify the effect of each phase and their interfaces on the SFP's mechanical properties. Micromechanical modelling based on finite element method offers a promising solution. In this study, a new micromechanical model for SFP is proposed, idealizing the material by representative volume elements. SFP mesostructure is represented as a simplified five element composite consisting of cement, asphalt mortar, aggregate, pore and cement-asphalt mortar interface. Periodic boundary conditions are used to simulate an infinite repetitive structure within a finite computational domain. The resulting model allows evaluating the stiffness and damage resistance of SFP in a computationally efficient manner. This model is utilized to explore the mechanical properties of SFPs and the results are compared with the experimental findings. The results show that the model captures the uniaxial compressive strength and stiffness for all materials examined. The model is further used to evaluate the effect of properties of individual elements of SFP on its stiffness and strength. The feasibility of using the proposed modelling approach to optimize the material design of SFP is discussed.