Fibre Reinforced Cement (FRC) sewer pipelines failed by 2 main mechanisms: failure of individual pipe lengths caused by chemical attack or overloading etc.; and failure of the joint rubber seals, which can occur even when pipe lengths are in good condition.
When joints fail, full-length lining is often the preferred renovation method. An alternative was to use robotic devices to test each joint's integrity and repair defective joints by injecting a sealant. However, joints currently performing satisfactorily may subsequently fail through on-going bio-degradation within the pipes' lifetime. An alternative 'permanent' solution was to locally seal all joints and this may be the most economic renovation technique, especially for longer pipe lengths.
Robotic devices and a range of injection materials exist, but to date there was no independent assessment of productivity / success rate of the technology or long term performance of available sealant materials. Robotic techniques can potentially operate during partial 'live' conditions, which may have additional operational and cost benefits.
This project assessed installation technology capabilities and applicability of sealant materials including their short / long term mechanical properties in-situ.
- Independent assessment of whether appropriate use of joint sealing techniques can offer a cost effective permanent solution for FRC pipelines, and hence reduce the risk associated with introducing these new methodologies
- Exploitation of techniques that may enable repair during 'live' operational conditions with reduced cost and customer inconvenience
- Potential reduction in capital maintenance expenditure, and reduced sewer infiltration and exfiltration.