ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS VICKSBURG United States
This report focuses on the laboratory study to evaluate a number of foam materials for their suitability as crater-backfill materials. Seven foam formulations were evaluated between the summer of 2015 and the spring of 2016. Four of these materials were commercially available. The remaining formulations were designed specifically to support this project. The materials were analyzed for compressive strength, reactivity, and expansion ratio, in addition to other properties. Ultimately, two foam materials were identified and recommended for future development efforts at the field scale. All of the materials evaluated in this study were deemed hydro-sensitive, as the structure of the material and the critical properties for performance changed when the foam reacted in the presence of water. This issue should be addressed through contingent actions, such as isolation from water sources and adjustments to the formulation in future development efforts.