Mathematical modeling and applications for concrete carbonation

Abstract

A new concept, carbon dioxide (CO2) transport in concrete, is proposed in this paper to describe solute-transport processes. Using this concept, a new one-dimensional mathematical model was developed to describe the transport phenomena of carbon dioxide in concrete structures. By treating transport phenomena as a concrete carbonation process, a one-dimensional linear partial differential equation was derived based on the principle of mass balance and convective-dispersive equation and was found the analytical solution by the separation of variables and the Laplace transform methods combined with some substitution approaches. The concrete carbonation numerical results were determined using parameters, such as the diffusion coefficient, CO2 concentration, carbonation depth and time, occurring in concrete structures. The numerical results are presented to illustrate the practical applications of this model. These results are shown clearly that the proposed model may actually describe the concrete carbonation process chemically and physically. It is suggested that experiment should be performed to select suitable parameters for numerical simulations.