The Natural Pozzolan Association is a network of natural pozzolan producers working to improve the performance and durability of the nation’s concrete infrastructure through the increased understanding and use of naturally-occurring hiqh quality supplementary cementitious pozzolanic materials.


Natural pozzolans are a class of siliceous or siliceous and aluminous materials which, in themselves, possess little or no cementitious value but which will, in finely powdered form and in the presence of water, react chemically with calcium hydroxide at ordinary temperature to form compounds possessing cementitious properties that greatly improve concrete durability and perfomance. The quantification of the capacity of a pozzolan to react with calcium hydroxide and water is given by measuring its pozzolanic activity. Natural pozzolans are sustainable and of magmatic origin.