Natural zeolite may be designated, in accordance with the European standard EN 197-1, as a natural pozzuolana.
Similar to other pozzuolanas, it does not harden after mixing with water.
However, if pulverized, it reacts in the presence of water with soluble calcium hydroxide creating compounds of calcium silicates and calcium aluminates which are the carriers of gradually increasing hardness. Using zeolite in the building industry:
- Zeolite is used as an anticorrosive admixture of cements. Applying 15 weight-% Zeolite as a substitution for normal Portland cement, a sulphate-resistance is obtained comparable to that of sulphate-resistant Portland cement. The usage of Zeolite is suitable for applications in demanding aggressive sulphate environment.
- Zeolite may be used as an inert admixture to sealing mixtures for ecological buildings to prevent the spread of contaminated waters from old ecologic loads, chemical or from any other industrial enterprises.
- Zeolite improves the stability of cement suspensions significantly. It is suitable to prepare cement admixtures for underground sealing tanks and grouting of hoods, as well as for injection mixtures of cable couplings.
Zeolite cement suspensions settle more slowly and separate into a solid phase and a liquid phase slowly too. The stabilizing effect of zeolite is connected with its sorption and exchange properties.
- Zeolite is used as an additive for the production of light construction and insulation building materials and pozzuolana cements.