An Analytical Solution of Chloride Transfer into RC Pipe Pile by Convection–Diffusion Effect Considering Time-Dependent Surface Chloride Concentration

• Published in: Iranian journal of science and technology. Transactions of civil engineering 2024, Vol.48 (5), p.3273-3283
• Main Authors: Chen, Deqiang, Mo, Peng, Chang, Zhenchao, Hao, Tianzhi, Li, Zhaofeng
• Format: Article
• Language: English
• Subjects: Chloride; Chloride transport; Chlorides; Civil Engineering; Concrete aggregates; Concrete pipes; Convection; Diffusion; Diffusion effects; Diffusion rate; Engineering; Exact solutions; Finite difference method; Immersion; Integral transforms; Mathematical analysis; Permeability; Permeability coefficient; Pipe piles; Porosity; Pressure effects; Reinforced concrete; Research Paper; Seawater; Submerging; Time dependence; Transport processes
• ISSN: 2228-6160; 2364-1843
• DOI: 10.1007/s40996-024-01372-2

Marine reinforced concrete (RC) pipe pile in the immersion zone experiences the influence of both diffusion and convection effects. Additionally, the surface chloride concentration of RC pipe pile exhibits time-dependent behavior. In the view, this paper employs the methods of function transformation and integral transformation to develop a convection–diffusion analytical model of RC pipe pile considering time-dependent surface chloride concentration, which can evaluate chloride transport process of RC pipe pile in the immersion zone. After validating the accuracy and applicability of the proposed analytical model through finite difference method and available experimental data, the influence of model parameters on the chloride concentration in RC pipe pile is analyzed. The investigation places particular emphasis on studying the influence of convection effect and time-dependent surface chloride concentration on the chloride concentration in RC pipe pile. Compared with the diffusion model, the convection–diffusion model accelerates the transport process of chloride in RC pipe pile. Compared with the constant surface chloride concentration model, the exponential surface chloride concentration model slows down the transport process of chloride in RC pipe pile. Both the seawater pressure and permeability coefficient of concrete have positive effects on the chloride concentration in RC pipe pile, while the concrete porosity and aggregate size have negative effects. Increasing the seawater pressure, permeability coefficient, porosity and aggregate size by 10%, respectively, resulted in a 9.09%, 9.09%, − 10% and − 13.75% variation in the convection effect of the RC pipe pile, respectively.