Numerical simulation of interfacial transition zone in ternary blended cement based composites

Author(s): Y. Gao, G. D. Schutter, G. Ye, H. L. Huang, Z. J. Tan, K. Wu
Paper category: Proceedings
Book title: Proceedings of the Seventh International Conference on Concrete under Severe Conditions – Environment and Loading
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 274-283
Total Pages: 10
Language : English

Abstract: The interfacial transition zone (ITZ) surrounding aggregate often plays a significant role in the overall performance of cementitious materials, for instance, the mass diffusivity of ions. Therefore, a reliable characterization of ITZ microstructure is important when material behavior of concrete needs to be assessed. Numerical simulation techniques have witnessed fast development as several integrated hydration models were proposed. However, to some extent, the relevant modeling skills referring to ITZ actually seem insufficient. In this paper, based on the continuum hydration model HYMOSTRUC, the microstructure of ITZ in ternary blended cement based composites has been simulated. In particular, two factors are emphasized. Firstly, within hydrating paste, cementitious particles hydrate upon variable local water binder ratio, as caused by the wall effect. Secondly, the moisture transport due to capillary suction is incorporated to obtain a better approximation of realistic hydration situation. For the sake of illustration, the aggregate-ITZ-bulk paste microstructure of ternary blended mortars with varied nominal water binder ratios, i.e., 0.3, 0.4, 0.5, are simulated. It is found that the simulated microstructural features match well with experimental measurements, as carried out in a previous study by means of back scattered electron (BSE) image analysis.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00