MODELING OF CARBONATION BASED ON THERMO-HYGRO PHYSICS WITH STRONG COUPLING OF MASS TRANSPORT AND EQUILIBRIUM IN MICRO-PORE STRUCTURE OF CONCRETE

Abstract

A carbonation model based on thermo-hygro physics is presented in this paper. Reaction of C-S-H gel was newly added to the existing model as well as calcium hydroxide reaction, and a micro-pore structure model for carbonated concrete was improved by considering volume change and surface-area increase of hydrated products. The proposed model coupled with moisture equilibrium/transport gives reasonable predictions for carbonation progresses under low and high CO₂ concentrations in a unified manner. In addition, temperature dependent parameters were installed in the system. Although detailed mechanisms should be further investigated, the proposed methodology is able to simulate carbonation phenomena under various temperature conditions.