Rehabilitation with cured-in-place plastic pipes - experiences and outlook

Important results from the project

The project aimed to ease water utilities condition monitoring of installed CIPP(cured in place pipe) and to perform procurement of CIPPfor sewers. In total 25 liners in use were excavated and analysed in the lab to assess the chemical and mechanical condition. A procedure to evaluate new installations of CIPP was created and a guide on important matters to consider when procuring CIPP were also formed. The chemical compositions of CIPP was reviewed to spread knowledge on possible environmental and health risks to consider with the chemical composition of CIPP.

Expected long term effects

The chemical resistance for excavated CIPP were in general good and they were in good condition. Some CIPP showed signs of material changes due to use and other defects connected to installation. The apparent ring stiffness were in all cases above 2 kN/m2 and in most cases well above. The project considered the quality control of new installation of CIPP to be neglected, something that needs to be improved to increase the general quality. The procurement guide is expected to ease for water utilities, but consensus about the level of the terms could not be reached within the reference group.

Approach and implementation

Before starting the project, the greatest risk was to acquire excavated CIPPThis was successful thanks to large commitment from water utilities and CIPP installation companies. It turned out harder than expected to find installation protocols, which was considered to be connected to the neglected quality control of new installations of CIPP in Sweden. To reach consensus within the reference group how the guidelines for procurement should be termed was not successful, to expect that was probably a to simplistic starting point from the project.