Fundamental Study of Alkali-Activated Powder

Abstract

This paper presents development of alkali-activated powder for use as binder in construction work. The precursor was consisted of fly ash and ordinary Portland cement for the production of geopolymer paste. The replacements of fly ash by ordinary Portland cement were 0, 10, 20 and 30 by weight of binder. The NaOH concentration of 10 molar and sodium silicate solution were used as alkaline activator. The liquid to binder ratio of 0.4 and 0.5, sodium silicate to NaOH solution of 1.0 and 2.0 were used as for all mixes and curing at 25 and 60 degrees Celsius. Geopoly paste that has been thoroughly grinded, called alkali powder, for use as binder in construction work. In which the binder in construction consists of alkali-activated powder, Portland cement and silica fume. The replacements of alkali-activated powder by ordinary Portland cement and silica fume were 40 and 10 by weight of binder respectively. The NaOH concentration of 2 molar and water. The water to binder ratio of 0.45, were used as for all mixes and curing at room temperature.

The compressive strength results of hardened geopolymer paste were increased with increase ordinary Portland cement replacement. And the results of testing the alkali-activated powder setting time showed that, when the amount of ordinary Portland cement in geopolymer paste increased, faster alkali-activated powder setting time. And when the incubation temperature of the geopolymer paste increased, the setting time of the alkali-activated powder slows down. The above information can be used as basic information in development of alkali-activated powder for use as binder in construction work.