Numerical study of ITZ contribution on mechanical behavior and diffusivity of mortars

Simulating the effect of microcracks on the diffusivity and permeability of concrete using a three-dimensional model

“…Such effects were not considered in the simulations presented in this study for the sake of simplicity and because we were mainly interested in quantifying the effects of microcracking. Furthermore, the effect of ITZ on transport properties is very small relative to the effect of microcracks, as shown in our previous experimental and numerical studies [Wong et al, 2009;Abyaneh et al, 2013a] and more recently in [Bernard & Kamali-Bernard, 2015]. Therefore, the findings of this study are not expected to be substantially influenced by this approximation since the effect of the added microcracks would be far greater than that of the ITZ.…”

Multi-scale analytical theory of the diffusivity of concrete subjected to mechanical stress

“…In reality, the presence of the porous ITZ zone modifies the structure of the paste far away from the aggregates and leads especially to a decrease of its porosity in order to respect the water conservation [20]. Herein the present study, however, the effect was not considered.…”

“…A number of empirical and theoretical equations between the diffusivity in cement paste and the porosity of cement paste have been established, e.g., in the work [20,21,25,26]. Among them, the theoretical model proposed by Zheng and Zhou [21] has demonstrated to have good agreement with the available experimental data, and it was thus utilized in this work.…”

“…1(a), at the meso-scale concrete was often considered as a three-phase composite composed of coarse aggregate particles, cement paste matrix (herein it is denoted as ''Paste matrix-I'') and the interfacial transition zones (i.e., the ITZs) between the former two phases, with each phase having its own distinct mechanical and diffusion characteristics. In which, the ITZ phase has been shown to have a dramatic influence on the mechanical and transport properties of concrete, and is often considered as a third phase in the composite description of concrete [7,11,[18][19][20]. Fig.…”

Towards a realistic morphological model for the meso-scale mechanical and transport behavior of cementitious composites

“…This is generally an extension of the mortar phase, with the aggregates considered as embedded in the ITZ phase. In this particular study, the ITZ has been assumed to have no influence on the overall compressive behavior of the concrete specimen [10,35] or on the homogenized transport properties [35].…”