Fly-ash-stabilized gypsiferous soil as an embankment material

A highway expansion project was proposed at the boundary of Texas and New Mexico State, where gypsum deposits are overlaid almost the entire construction area. In order to use the local gypsiferous soil as a suitable embankment material, soil stabilization using fly ash as an admixture was proposed. Even though the application of fly ash as a soil stabilizer started around 1950s, there are not many case histories related to the stabilization of gypsiferous soils using fly ash. In this study, a series of laboratory testing on gypsiferous soils before and after the addition of fly ash is presented. Analysis is done on the physical and mechanical properties of the stabilized soils as well as the chemical processes involved in the stabilization.