Properties of alkali activated mortars with combinations of different starting materials
Alkali-activated cements are rather new binders that are produced by the activation of pozzolans with different alkali solutions. The utilization of these types of materials might solve an important ecological problem in terms of the use of an industrial sub product. Among the precursor materials used, blast furnace slag (BFS) and fly ash (FA) has been prominent ones because of their favorable chemistry. Turkey is rich in natural pozzolans and has extensive deposits of pumice. Pumice may contain up to 75% SiO2 and has a high pozzolanic activity. There are limited numbers of studies about using pumice powder (PP) as a binder in alkali activated mortars. In this study, alkali activated mortars were produced with using different amount of BFS, FA and PP. The mortar mixture proportions were 1:2.5:0.5 by weight of binder, sand and water respectively. BFS to binder ratio was kept constant as 0.5. PP was replaced with FA by 10, 20 and 30% by weight. Sodium hydroxide (NaOH) was chosen as the alkaline activator. Compressive strength development, physical properties and abrasion resistance of mortars were determined. Compressive strength increased with the increase in PP ratio and NaOH amount. Physical properties did not change considerably. Abrasive resistance improved by increase in the NaOH amount.