PUMICE - A strong, durable porous glass aggregate of volcanic origin. An ideal natural material for use in structural lightweight concrete. With the continuing increase in energy costs, the use of a natural aggregate marks a return to the economic principles associated with the use of lightweight concrete. Pumice was used in ancient Rome over 2,000 years ago in the construction of the Pantheon, the Coliseum, the immense vaults of the public baths and many other notable structures still standing today. Pumice aggregate concrete has been used in Germany and France since 1850 and is still a major construction material. AGG-LITE VAC-LITE - The trade names for the pumice aggregates being produced meets or exceeds the requirements established by the American Society of Testing Materials for use as an aggregate in structural concrete and concrete block. This aggregate has been approved for use by the Department of Building and Safety, the City of Los Angeles and by the International Conference of Building Officials for specific precast concrete products. UNIT WEIGHT - As low as 60 pounds per cubic foot are possible with pumice aggregate concrete. There is a corresponding decrease in strength as the volume of pumice is increased as indicated on the Strength vs. Unit Weight graph (see "Engineering Data" page.) COMPRESSIVE STRENGTH - In excess of 4,000 pounds per square inch can be attained with pumice aggregate concrete at a unit weight in the range of 110 pounds per cubic foot. WORKABILITY - Is excellent even at extremely low slump due in part to the spherical shape of the aggregate particles.With properly designed and batched mixes there is no segregation or excessive surface water. Hardened pumice aggregate concrete has the unique capability of being nailed, sawed or drilled with ordinary hand tools.   California Lightweight Pumice, Inc., San Clemente, CA 92672