Epoxy resin concrete has high strength, good durability, good toughness, short forming time, the advantages of easy construction, etc. As a high-performance material, it has been applied in various fields such as machinery, construction, chemical industry, truss structures, etc. Based on its high strength, better seismic resistance than that of concrete structures, lower cost than that of steel structures, better plasticity, assembly, and simpler construction technology than those of wood structures, it has very broad prospects for development and space application. In this study, an atomistic modeling approach has been used for predicting the mechanical properties of epoxy concrete. Fully atomistic models were built by varying the weight percent of the polymer (epoxy) and the aggregates (silica and calcite) using molecular dynamics (MD) simulations. The modulus of elasticity of epoxy concrete was predicted by calculating the induced stress and developed strain of the distorted model. The results showed that the elastic modulus of epoxy concrete was higher by 41% than that of conventional cement concrete. The effect of epoxy resin binder was found to be significant for the adhesion between the epoxy and aggregates, which enhanced the compressive strength. Addition of calcite microfiller helped in reducing the void content in the aggregate mixture and thereby increased the strength of polymer concrete. The simulation results agreed well with experimental measurements reported in the literature. The study demonstrates that MD can be used as a useful tool for material design and performance prediction and can also help in understanding the fundamental chemistry?mechanics relationship of epoxy concrete at an atomistic scale.