• The big difference between geopolymers and regular Portland cement is that their setting mechanism does not depend on HYDRATION, but rather in a POLYMERIZATION, which happens in a short period of time, while cement's hydration is mostly completed within one month, and fully completed only until one year.

• Geopolymer paste can be combined with the same aggregates used for Portland cement, for its use as mortar or concrete.

Uses:

• Among the many potential uses of geopolymer materials are heat insulation for re-entry for space crafts and the storage of corrosive substances, however possibly the most significant use is as a replacement for PORTLAND CEMENT as a cementitious binder in the construction industry.

• Geopolymer's excellent mechanical and long term properties greatly exceed those of Portland cement and position geopolymer as an interesting new alternative to solve old civil engineering problems: how to obtain high early strength and durability.

Properties:

• Compressive strength: 6,000 – 16,000 psi (depending on the fly ash used).

• Flexural strength: Approximately twice that of OPC.

• Chemical resistance: Two to Five times greater resistance to sulfuric acid attack compared with OPC; virtually immune to sulfate attack.

• Porosity/Permeability: Ten times lower than OPC utilized in typical structural applications.

• Strength gain: Full strength is gained within 1 to 3 days; 80% of ultimate strength is gained within a couple of hours.

• Setting time: 30 to 120 minutes

• Fire Resistance: Non-flammable non-combustible.

• Carbon dioxide emission: 10% or less compared with OPC (i.e., 90% CO 2 emission reduction).

• Alkalis are incorporated in the geopolymer paste, therefore will not react with aggregates

• Geopolymer does not have any phase that can lead to ettringite formation

• Geopolymer's structure will allow much less ion penetration (Chlorine and Carbonate ions).

• Small drying shrinkage due to the geopolymer's smaller capillaries and its overall higher density.