CHARACTERIZATION ALKALI-ACTIVATED MORTAR MADE FROM FLY ASH AND SANDBLASTING

This research is to find out the contribution of waste energy utilization in Indonesia as a binding agent of alkali-activated mortar. In a previous study, researchers investigated mortar made from class F fly ash/GGBFS/micro-silica in Japan. The inclusion of GGBFS is to shorten/normalize the setting time and micro-silica is to improve mortar performance. This research is then continued by using abundant waste material in Indonesia, namely class C fly ash, by making cubic mortar specimens. Setting time of class C fly ash paste from Indonesia is very fast, in contrast to that of class F fly ash paste from Japan. Sandblasting as abundant waste material in Indonesia is substituted to class C fly ash to lengthen the setting time of paste and to improve standard deviation of a compressive test of mortar specimens. On the other hand, the addition of sandblasting waste has a negative effect, because it reduces a compressive strength of mortar specimens.