We have a new publication from CBM with Puttipong Srimook. We investigated why and how we can obtain the S-shape water imbibition curve in the case of concrete. There are two possible inflection points. The first one is controlled by cracks, facilitating quick water adsorption and a quick increase in the moisture transport coefficient due to water re-distribution from the crack space to the matrix.
The second one is controlled by dynamic microstructure change caused by the colloidal nature of C-S-H.
We investigated different kinds of possibilities numerically using the newly developed rigid-body spring network + truss-network + crack-channel models. This model can precisely simulate the 1) mass transport affected by dynamic microstructure change by C-S-H and 2) crack opening – closure caused by the volume change of matrix caused by the C-S-H gel water content change.

P. Srimook, I. Maruyama, Anomalous moisture transport in dried cementitious material: A numerical analysis, Constr. Build. Mater. 449 (2024) 138365. https://doi.org/10.1016/j.conbuildmat.2024.138365.