State-of-the-Art Review on Application of Spray-Applied Pipe Linings in Gravity Stormwater Conveyance Conduits

Gravity stormwater conveyance conduits are in need of special attention in terms of proactive/preventive asset management and rehabilitation/renewal strategies. Failure of these systems is costly for departments of transportation, both directly due to the replacement of the failed system and indirectly due to the time and money, and even in some cases lives lost, for the users of the highway. Different studies show that design and implementation of culvert renewal and rehabilitation methods are complex due to the depth of soil cover, traffic loads, type of embedment, culvert material, age, level of deterioration, access limitations, and so on. Spray-applied pipe linings (SAPLs) are used to renew deteriorated culverts and drainage structures for semistructural and structural applications. SAPLs consist of spraying cementitious or polymer (resin-based) materials inside a host culvert. Geopolymer and cementitious materials are categorized under cementitious SAPL, and polyurea, polyurethane, and epoxy are types of resins that are used in polymeric SAPL. The objective of this work is to present a literature review on progress acquired over the years in understanding the application of SAPLs in gravity stormwater conveyance conduits. This literature review comprises not only design methodologies and equations, but also covers methods and means for performance specifications and installations in rehabilitation and renewal of different types of SAPLs, such as invert paving, hand spraying, machine spraying, and others. Publications are identified that directly or indirectly reported the application of SAPLs in gravity stormwater conveyance conduits over the period from 1982 through 2021. Experimental and numerical literature was categorized into SAPL materials, structural behavior, soil–structure interaction, durability, and surface friction to be identified for flow capacity improvement. This literature review defines and categorizes the SAPL materials for structural and semistructural applications and suggests whether SAPLs can renew deteriorated culvert pipes in each of these conditions. Further research is needed to identify the behavior of different SAPL materials and their soil/host culvert structure interactions. Parts of the important gaps in knowledge are the impact of adhesion to the host culvert and the statistical percentile occurring this adhesion.