Location: Durham, NC Overview: This project involved the placement of an engineered lightweight fill at Duke Hospital to support an elevated slab over basement-level loading docks. Cellular Concrete was selected to reduce structural loading while providing a durable, high-performance fill solution compatible with the hospital’s structural and architectural requirements. Challenge: The elevated slab design required a fill material that would minimize dead load on the structure without sacrificing bearing capacity. Traditional fill materials posed risks of overloading the elevated slab and required extensive compaction, which was impractical in the confined conditions above the active loading dock area. Solution: Class V Cellular Concrete with a cast density of 45 pcf and a minimum compressive strength of 200 psi was selected as the engineered fill. The material’s high flowability allowed it to be placed efficiently, self-level into position, and eliminate the need for mechanical compaction. Its lightweight nature significantly reduced dead load while still providing the required bearing capacity for the finished slab system. Results: • Material: Class V Cellular Concrete • Cast Density: 45 pcf • Minimum Compressive Strength: 200 psi • Application: Lightweight fill over elevated slab above basement loading docks • Key Benefit: Reduced structural loading with no compaction required