Experimental study and multi-physics modelling of concrete under supercritical carbonation

• Published in: Construction & building materials Vol. 227; p. 116680
• Main Authors: Bao, Hao, Yu, Min, Xu, Lihua, Saafi, Mohamed, Ye, Jianqiao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.12.2019
• Subjects: Carbonation depth; Concrete; Irregularity; Random aggregate model; Supercritical carbonation; Supercritical carbonation; Concrete; Carbonation depth; Random aggregate model; Irregularity
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2019.116680

•We experimentally and numerically studied irregularity of carbonation depth of concrete.•We proposed novel method to randomly distribute aggregates.•We included both aggregates and cement porosity in the numerical model.•We investigated the effects of volume ratios and gradation of aggregate on the carbonation depth. This paper presents both experimental study and multi-physics modelling of supercritical carbonation of concrete. A novel mathematical model is proposed to simulate random distribution of coarse aggregates in concrete. Supercritical carbonation tests of concrete are carried out and the measured carbonation depth is compared with the simulation results. On the basis of previous research on random field of porosity and supercritical carbonation of cement mortar, a new supercritical carbonation model is developed to study the effect of randomly distributed coarse aggregates and porosity on the irregularities of carbonation depth of concrete. The effect of the type, volume fraction and gradation of coarse aggregates and the porosity of ITZ on the distribution of irregular carbonation depth are also studied. The results demonstrate that the proposed two-dimensional random coarse aggregates model can be used satisfactorily to generate different types, volume fraction and gradation of coarse aggregates with the designed mix proportion within a confined space. The method provides a better and more realistic predictive model for simulating carbonation depth of concrete due to random distribution of coarse aggregates and porosity.