Application of injection material for rehabilitation of underground pipeline using fly ash surfactant mixtures

Abstract

A large amount of waste is produced at coal preparation plants. The properties of the waste vary depending on the mineralogical content of the mother rock in which the coal is embedded. The quality of the waste depends on the method of mining and cleaning, but it consists mostly of clays, quartz, carbonaceous materials, mica, pyrites and so on. About 80% of coal-ash is now utilised in Japan, and the remaining is disposed of at disposal sites. However, the life span of each disposal site is limited and it is difficult to find new disposal sites. It is therefore desirable that the percentage of utilisation of fly ash be increased in every possible way in Japan. One way of achieving this goal is to incorporate more fly ash in cement mixes that can be applied as the injection material for natural/artificial openings. In this study, different combinations of fly ash, surfactants and water were investigated to determine the influence of surfactants on the properties of fly ash mixtures used in slurry pipe jacking.