Trenchless rehabilitation for concrete pipelines of water infrastructure: A review from the structural perspective

Concrete-based pipelines or linings are widely used for water and sewer systems. However, concrete pipes suffer from the problems of aging and deterioration due to complex loading (internal and external), severe service environments, and the brittle nature of concrete. This paper provides a state-of-the-art review of trenchless rehabilitation methods for concrete pipelines, including spray-in-place, grouting, sliplining, modified sliplining, cure-in-place pipe, close-fit, and fiber-reinforced polymer lining. In addition, an emerging structural retrofit method with Engineered Cementitious Composites (ECC) was introduced. The rehabilitation methods were classified into non-structural, semi-structural, structural, as well as the retrofit of structure and function. The technical features, advantages, drawbacks, and application conditions of each method were summarized to provide the basis for method selection. ECC can be applied as a coating by manual spraying and centrifugal spraying methods. The tailored characteristic of self-stressing enhances the integrity of the ECC liner and host pipe. The intrinsic advantages of ultra-high tensile ductility, anti-corrosion, jointless technique, tiny crack widths, self-healing behavior, as well as low cost make ECC a sustainable and resilient material for pipe rehabilitation and retrofit with increased load capacity, enhanced durability, and leakage-proof performance. © 2021 Elsevier Ltd