Pumice is a proven natural coarse aggregate for the production of structural lightweight concrete specified to ASTM C330. Structural lightweight concrete made with Glass Mountain Pumice™ Lite-Rock™ lightweight aggregate meets or exceeds those specifications as tested by UL Testing. It also meets or exceeds the ASTM E119 Fire Endurance Rating as tested UL Testing.
Lite-Rock™ mix designs produce concrete with a standard 28-day compressive strengths averaged over 4000 PSI. ASTM C330 reports calculated equilibrium density of 106.4 pounds per cubic foot based on oven-dry density of 103.4 pounds per cubic ft. Lite-Rock™ also meets or exceeds ASTM E119 at two to four hours in structural floor and roof assemblies depending on thickness. Tests indicate structural lightweight concrete made with Lite-Rock™ transmits less than half as much heat as normal weight concrete of similar thickness.