Molecular Dynamics Study of the Bonding Mechanism at the Epoxy/Concrete Interface

Abstract The damage to carbon fiber reinforced concrete structures primarily occurs due to the degradation of adhesion at the binder-concrete interface, making it the most susceptible to failure. This leads to the blockage of stress transfer between the epoxy resins and the concrete, which in turn makes the structural durability degraded. This paper establishes a molecular model of reticulated epoxy resin with a high degree of cross-linking and a molecular model of C-S-H gel with a calcium-silicon ratio of 1.69, using sub-dynamic simulation methods. Based on the multi-scale mapping relationship of “CFRP/concrete interface - epoxy resin/concrete interface - epoxy resin/C-S-H interface,” we innovatively developed a molecular model of the epoxy resin/C-S-H interface at the nanoscale. Molecular dynamics simulations were employed to investigate the chemical bonding between the epoxy resin and the C-S-H matrix. This study reveals the bonding mechanism at the molecular level between epoxy resin and C-S-H, providing valuable insights into the epoxy resin/C-S-H interface.