Service life of underground concrete pipeline with original incomplete cracks in chlorinated soils: Theoretical prediction

Abstract This paper presents a theoretical model, considering the effects of original incomplete crack on the chloride ion diffusion, to predict the service life of underground concrete pipelines in chlorinated soils. The deterioration process of pipelines is divided into the chloride ion diffusion phase, the initial stress generation phase and the initial crack generation phase, three sub phases according to the corrosion mechanism. A dual compound media diffusion model and a partially cracked thick-walled double cylinder model are developed to model the three deterioration phases, based on which a theoretical approach is proposed to predict the service life of underground pipeline. An ABAQUS model is developed to check the validity of dual compound media diffusion model for the first phase, which ensures reliable results are propagated to subsequent analysis. Extensive parametric studies are conducted to demonstrate the effects of the original crack depth and width, the soil pressure, the tensile strength of concrete, the cover thickness and the diameter of the reinforcing bar on the service life of underground concrete pipelines. The proposed approach, properly taking the effects of original incomplete cracking and soil pressure into account, would be served as a significant theoretical base for the design and maintenance of underground pipelines in chlorinated soils.