As part of decommissioning an underground oil tank at an institutional facility in Washington, DC, it needed to be filled with excavatable material that was lighter than the roughly 55lb/cuft heating oil it was designed to hold.
The tank is located in a small empty lot, which is slated for redevelopment in approximately three years.
To be officially considered decommissioned, the tank had to be completely filled. It is slated for removal as part of the redevelopment process of the area (it sits within a future basement excavation) so the fill material had to be excavatable.
CJGeo proposed 20lb/cuft cellular concrete for the abandonment grouting. This afforded plenty of factor of safety to reduce the likelihood of settlement induced by filling the tank, and maximized excavatability
CJGeo placed the fill material over a period of two days onsite. Because cellular grout is highly mobile, no entry was required during the placement of the fill material, which designed a significant amount of risk out of the process.
The 1200CY placement was performed over two days onsite.