Numerical simulation of chloride diffusion in reinforced concrete structures with cracks

Author(s): C. K. Y. Leung, D. W. Hou
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: 261-273
Total Pages: 13
Language : English

Abstract: Steel corrosion is a major problem with concrete structures. For a given cover thickness, the corrosion initiation time depends on the chloride diffusivity. Under practical loading situation, concrete structures are allowed to crack. As chloride diffusion occurs at a higher rate through the crack than the bulk matrix, cracking will facilitate the initiation of steel corrosion at the location intersected by the crack. In cracked concrete, diffusion occurs as a two-dimensional process. Besides diffusing along the crack, chlorides also migrate in the perpendicular direction due to concentration gradient between the crack and the adjacent matrix. Such a diffluence effect will significantly slow down chloride penetration through the crack. In the present study, finite element analysis is performed to study the effect of cracking on chloride diffusion in cracked concretes with different values of Do (diffusion coefficient of concrete matrix), Dcr (coefficient of diffusion through cracks) and w (widths of cracks). Based on the simulation results, we will derive the empirical equation for an equivalent diffusion coefficient (Deq) which can be employed directly in the solution of the one-dimensional diffusion equation to calculate the corrosion initiation time. The study will provide a convenient but accurate approach for predicting the chloride diffusion under real world situations where cracks are present in a concrete structure.

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