Abstract: Disclosed are improved compositions, systems, methods and techniques for processing and preparing cement, cement constituents and concrete formulations involving natural pozzolans. In various embodiments, the water demand, compressive strength, set times and workability in concrete incorporating certain natural pozzolans can be improved by blending with calcium carbonate powders, while further improvements can be accomplished if the calcium carbonate is inter-ground with the natural pozzolan to a desired and/or minimum fineness. This addition of calcium carbonate, fly ash, ground granulated blast furnace slag, ground glass and various acids to a natural pozzolan can desirably reduce water requirements and improve the physical performance characteristics of the natural pozzolan and the overall characteristics of the concrete.

Abstract: Disclosed are improved compositions, systems, methods and techniques for processing and preparing cement, cement constituents and concrete formulations involving natural pozzolans. In various embodiments, the water demand, compressive strength, set times and workability in concrete incorporating certain natural pozzolans can be improved by blending with calcium carbonate powders, while further improvements can be accomplished if the calcium carbonate is inter-ground with the natural pozzolan to a desired and/or minimum fineness. This addition of calcium carbonate, fly ash, ground granulated blast furnace slag, ground glass and various acids to a natural pozzolan can desirably reduce water requirements and improve the physical performance characteristics of the natural pozzolan and the overall characteristics of the concrete.