Suction and volume changes of a bentonite-enriched sand

Landfill barriers are used to control or prevent both migration of leachate from the landfill waste and the ingress of the surrounding groundwater. A typical barrier system may include a combination of engineered barriers and fluid collection layers, Bentonite-enriched sand is a commonly used barrie r material, The addition of relatively small amounts of bentonite (5-15%) c an dramatically improve the performance of a granular material, providing b oth a low permeability and an enhanced mechanical stability. This paper exp lores the suction and volume change characteristics of a bentonite-enriched sand. In addition to determining the dry density-moisture content relation ships for a range of compactive efforts, a series of oedometer tests has be en performed and a comprehensive number of suction measurements made, These data have allowed the suction and volume change characteristics to be defi ned. The results are presented and discussed, allowing a clearer understand ing of the long-term behaviour of these materials to be developed.