Mechanical Behaviour of Cement-Bound Gravels by Experiment-Based 3D Multi-Scale Modelling: Application to Non-Hazardous Waste Incineration Bottom Ashes Aggregates for Use in Road Engineering

Abstract

This paper presents a hierarchical multi-scale modelling approach devoted to investigating the mechanical behaviour of cement-bound gravels. Material studied is based on Non-Hazardous Waste Incineration (NHWI) bottom ashes. The elastic moduli of NHWI particles have been previously determined by an original indentation campaign never conducted so far on these types of aggregates. The results of the experimental campaign serve as input data to the developed numerical strategy. The modelling is based on the definition of Representative Elementary Volumes (REV) considering all the heterogeneities of the material. The "virtual laboratory" set up made it possible to determine the mechanical parameters characterizing the gravel treated with 3% of cement. The high value obtained of the internal friction angle (76 °) gives the material a good bearing capacity. The classification in mechanical classes 3 and 4 when the Young's modulus of the NHWI particles varies from 20 to 80 GPa proves the feasibility of the reuse of this type of industrial by-products in this sector of activity. The present modelling approach is validated by means of comparisons with experimental results of the literature.