ABSTRACT
The dissolution of portlandite leads to carbonation, which affects the sustainability of the concrete. Therefore, it is important to understand the dissolution behavior at the portlandite-water interface. The current contribution aims at the development of a multi-scale bridging modeling approach that connects the atomistic scale to the (sub-) micro scale. In this work, first, the biased molecular dynamics, metadynamics coupled with ReaxFF is employed to calculate the reaction path as a free energy profile of calcium dissolution at 298K in diluted water from the different surfaces of portlandite. The reason for the reactivity of (010) crystal plane is higher compared to the (001) surface is explained. In addition the influence of neighboring Ca on the dissolution rate is also investigated. The calculated rate constant of most important atomistic reaction steps provided an input for developing the upscaled model using a kinetic Monte Carlo (KMC) method.
