Synthetic pozzolans
Synthetic pozzolans are produced using local materials to provide a cementitious material that is uniform in chemistry and properties independent of the location where the materials are obtained. Two methods of production are described. One is a high temperature process in which materials are processed in a semi-molten or molten state. The second process is a low temperature aqueous process.
1. A synthetic pozzolan comprising:
at least 10% by mass of an activatable amorphous phase comprised of one or more of siliceous, aluminosiliceous and aluminous material, said activatable amorphous phase configured to be activated by conducting a chemical reaction to form a cementitious compound, and
a crystalline phase, wherein the crystalline phase comprises, in its majority, synthesized crystalline melilite or synthesized crystalline plagioclase feldspar.
2. A composite material produced by blending the synthetic pozzolan of claim 1 with an activator and water.
3. The composite material of claim 2 wherein the activator is selected from hydraulic cement (1-70 wt %), free lime (1-20 wt %), calcium hydroxide (1-20 wt %), and alkali hydroxides (NaOH, KOH 1 to 10 wt %), individually or in combination.