Mechanical response and spray technology for corrosion and voids concrete drainage pipes under traffic loads: simulation and full-scale testing

Abstract

In various drainage pipeline projects, people widely employ the reinforced concrete drainage pipelines with bell and spigot. Deterioration of drainage pipelines made from reinforced concrete, including bell-and-spigot misalignment, inner wall corrosion and wall bending, can lead to structural failure. Traffic loads is one of the main factors causing pipeline failure. As for the reinforced concrete pipeline, understanding its bending moment becomes very important for pipeline safety evaluation under traffic load. An array of the full-scale tests conducted on buried corroded and void concrete pipeline under traffic loads are introduced in this research. One model of full-scale test parameters is established through numerical simulation analysis, which is adopted with the aim of studying the bending moment of the pipeline made from the reinforced concrete, caused by traffic loads. Firstly, a traffic heavy load model of a pipeline with 1000 mm diameter under a maximum of 300kN was established. Additionally, as for the numerical model, its correctness was verified by full-scale tests. Then, these impacts of traffic load flow, soil cover depth, and position on pipeline bending moment is studied. In order to make the corroded pipeline achieve the original structural performance, this study used this newly developed PVA reinforced cement composite material with early strength and good durability to spray repair the pipeline. The results show that the most unfavorable condition is that with the heaviest traffic load, the vehicle rear axle acts directly on bell-and-spigot joints. If the depth of the soil cover is deeper, the initial pipeline stress will be higher, the influence of traffic loads on the pipeline will be lessened. However, even if a 3 m soil cover depth, heavy trucks still cause a large bending moment, and large-diameter rigid pipelines is designed to be shallow in the cover of the soil, the traffic loads will not be conservative enough in the congested. As to the corroded pipeline repaired by spraying, its structural performance is sufficient to fulfill the original pipeline structure property, which verifies feasibility of the material and technology.