Multi-scale model to simulate diffusion in high-performance concrete

Author(s): Yunsheng Zhang, Qian Jiang, Zhiyong Liu, Laibao Liu
Paper category: Conference
Book title: 2nd International conference on Microstructural-related Durability of Cementitious Composites
Editor(s): Guang Ye, K. Van Breugel, Wei Sun, Changwen Miao
Print ISBN: 978-2-35158-129-2
e-ISBN: 978-2-35158-123-0
Publisher: RILEM Publications SARL
Pages: 1025 - 1034
Total Pages: 9
Language: English

Abstract: 
Chloride transport property of concrete is of great importance to determine the durability of the concrete structure. In this paper a multi-scale microstructural model is applied to compute the chloride diffusivities of high performance concretes with different water-to cement ratios, fineness modulus of sand, volume fractions of aggregates and sand-to-coarse aggregates ratios. The 3D microstructure and of cement matrix, interface transition zone (ITZ) are stimulated by using digital-image-based models. Their corresponding diffusivities are computed based on the 3D microstructure. Finally, the fully multi scale diffusivity of high performance concrete is obtained by using a hard core soft shell microstructure model. An electrical accelerated chloride diffusion tests are also conducted to verify the computer simulation results. The results are showed that the predicted results have a good agreement of the same order with measured values. The higher W/C, greater sand-to-coarse aggregates ratios, smaller fineness modules and less volume fraction of aggregates have higher diffusion coefficients of mortar or concrete. In addition, the thickness of ITZ with 25 μm can be determined by the porosity as a function of distance from the aggregate surface.

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