Advancements in structural cured in place pipe (CIPP) materials, liner design and manufacture

Abstract

In the past, structural CIPP solutions have been reliant on traditional methods and materials, such as felt liners and polyester resins requiring a significant time and resource investment. As new and more demanding standards are introduced – such as the 2019 American Water Works Association (AWWA) “Structural Classification of Pressure Pipe Linings” protocol – the need for more innovative methods has grown. Composite materials borrowed from aerospace, renewable energy, and other fields, present an opportunity for more sustainable future solutions. This whitepaper reflects on the development of CIPP technology to date, in order to look forward to new advances in the use of composite materials for structural and pressure pipe rehabilitation. Progress over the last five decades will be analysed, including the introduction of standards such as the ASTM F1216. Details of new applications for composite materials will be examined, including the use of advanced fibres, new generation custom fibre weaving and specialised resins in the manufacturing of structural CIPP lining. The benefits of the use of composite materials will be discussed, including improved load carrying characteristics and a reduction in the thickness and weight of the materials required to achieve this. An overview of liner design and manufacture will be discussed, along with some of the latest advances in resin formulation and cure. The information shared will demonstrate why the most recent CIPP structural test protocols necessitate the use of innovative, advanced composite CIPP liners and novel resin curing technology.

Techniques