Durability properties of geopolymer mortars

Environmental concerns related to the production of cement in terms of energy consumption and emission of CO2 are driving the search for more sustainable alternatives. One possible alternative is to use industrial by-products as the binder. At present both fly ash and slag are frequently used as cement replacement materials. Both of these materials provide a more sustainable alternative to concrete and have been shown to increase durability in aggressive environments. Recent research has shown that it is possible to use fly ash or slag as a sole binder by activating them with an alkali component. The development of these materials is still at the early stages, with little knowledge about the long term performance of the materials. This paper reports the early age durability characteristics of three geoploymer mortars. It reports the compressive strength, resistivity and ultrasonic pulse velocity data at 28, 90 and 150 days, together with the results of sulphate exposure test.