The 4th Asian Concrete Federation Symposium on Emerging Technologies for Structural Longevity (ACF2023- ETSL)

5 / 2022-02-26 14:27:43

Mechanical properties of microcapsule-based self-healing concrete interface: a molecular dynamics study

C-S-H,Epoxy,Microcapsule,Molecular dynamics,Self-healing concrete

As a new material, microcapsule-based self-healing concrete can effectively inhibit the propagation of cracks and improve the durability of concrete structures. In this study, the composite models of microcapsule core (epoxy) with C-S-H were established, and its interfacial behaviors were studied by molecular dynamics simulation, which is intended to analyze the mechanical properties of the microcapsule-based self-healing concrete and the interfacial behavior between the microcapsule and the cement matrix on the microscopic level. Three C-S-H/ epoxy models, in which the epoxy resins were uncured and cured with different curing agents (MC120D/TEPA), were established to study the effect of curing agents on the interfacial mechanical property. Through the analysis of interfacial binding energy, radial distribution function and stress-strain curve, it can be concluded that curing agent has a great influence on the bonding behavior of epoxy resin and cement matrix. The cured-epoxy resin can increase the interface binding energy by at least 50%, and can increase the strength of concrete, which is due to the interaction of N atoms and O atoms in TEPA and Ca atoms in C-S-H and the hydrogen-bond interaction.