Simulation of chloride ion transport in concrete under the coupled effects of a bending load and drying–wetting cycles. (30th April 2020)

• Record Type: Journal Article
• Authors: Tongning, Cao; Lijuan, Zhang; Guowen, Sun; Caihui, Wang; Ying, Zhang; Pengshuo, Wang; Aoxue, Xu
• Is Part Of: Construction & building materials. Volume 241(2020)
• Publication Date: 2020-04-30
• Subjects: Concrete -- Bending load -- Drying–wetting cycle -- Variable coefficient of chloride ion transport -- Tortuosity; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118045
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A variable coefficient constitutive model for chloride ion transport under coupled bending and drying–wetting conditions is proposed. The model considers the key factors such as the porosity, tortuosity and saturation changes during the transport of chloride ions in concrete. The two-dimensional variable coefficient constitutive equations of water and chloride ion transport are solved by the alternating implicit finite difference method. Abstract: The transport of chloride ions in concrete under the coupled effects of a bending load and drying–wetting cycles accelerates the degradation of marine concrete. Based on the microstructure characteristics of concrete, the models of the tortuosity of concrete under a bending load were built. Considering the interaction between the transport of water and the tortuosity in the concrete microstructure, a nonlinear diffusion-convection model of the water and chloride ions transport in unsaturated conditions were also proposed in this paper. Finally, a two-dimensional variable coefficient model of chloride ion transport in concrete under the coupled effects of a bending load and drying–wetting cycles was also established based on Fick′s second law, which was numerically solved using the alternating direction implicit (ADI) method. The results show that the values predicted agree with those of experiments and those reported in the literatures.