Factors contributing to the failure of asbestos cement water mains

Abstract

Asbestos cement (AC) water mains were installed extensively in North America, Europe, and Australia from the late 1920s to the early 1980s and still form a significant component of water distribution networks of many cities. These water mains are ageing and some water systems have experienced a high breakage rate in AC mains in recent years. It is essential that a clear understanding be developed of the factors contributing to their failure to ensure that municipalities and water authorities can manage their AC water-main assets. In this paper, the historical failure data of AC water mains from the City of Regina were collected and correlated with their corresponding environmental setting, including soil type, water quality, climate, and construction and maintenance practices. The predominant factors that influence the AC pipe breaks were identified. It was observed that pipe age, diameter, climate, clay soil, and construction and maintenance methods all influence the failure of AC water mains in the city, with climate and clay soil conditions being the two critical factors. Some chemical attack from the conveyed water and soil pore water may have occurred and detrimentally affected the structural integrity of the AC water mains. Key words: asbestos cement pipes, water mains, pipe failure, clay soil, climate.