Asbestos Cement water mains deterioration and failure prediction models
Project Status Project Commenced
In the UK, there is approximately 50,000km of Asbestos Cement (AC) water mains, 60% of which have been in service for over 50 years, the majority (approximately 66%) being small diameter, 100mm or less. With time, it has been noted that the failure rate of AC mains is increasing, demanding the need of replacement which can cost around £5 billion.
Several studies have identified that the principal failure mechanism of AC water mains is:
- exposure to conveyed water that has an aggressive nature, typically low alkalinity
- exposure to aggressive soils, typically low pH
- failure of the joints, typically due to microbial attack on the natural rubber joint rings
All of the above deterioration mechanisms are directly proportional to time, i.e., the longer the exposure, the greater the level of deterioration. Whilst there may be opportunities to extend the life of such pipes through lining and pressure management, these interventions are unlikely to be a success due to the small diameter and long-term exposure to the aggressive conditions that has already taken place.
If the level of AC main failures (pipe and joints) continue to increase, this will impact on the number of interruptions to supply and levels of leakage.
This project will be a collaborative project with the Water Services Association of Australia (WSAA).