Thin-shell Concrete Dome Construction. Proof-of-concept, scale model, Juneau, Alaska, Nov 2009.
This 5/8 sphere (volume) dome is ~ 1 cm (1/2 inch) thick, 2.8 m (8 1/2 feet) in diameter. Primary reinforcement is "C-Grid" carbon fiber epoxy grid made by Chomarat, for concrete reinforcement.
3 cm closed-cell urethane foam sprayed on interior for thermal insulation.
Strong enough for Earth burial for protection from weather, and from shrapnel and small-arms fire in combat areas. See: