Effect of Sodium Hydroxide (NaOH) Concentration on Compressive Strength of Alkali-Activated Slag (AAS) Mortars

Abstract

Energy saving in building technology is among the most critical problems in the world. Thus it is a need to develop sustainable alternatives to conventional concrete utilizing more environmental friendly materials. One of the possibilities to work out is the massive usage of industrial wastes like ground granulated blast furnace slag (GGBS) to turn them to useful environmental friendly and technologically advantageous cementitious materials. In this study, ground granulated blast furnace slag (GGBS) is used to produce of alkali activated slag (AAS) mortar with the effect of alkaline activator concentration. Alkali activated slag (AAS) mortar is accelerated using alkaline solution of sodium silicate mixed with sodium hydroxide. The fixed ratio of sodium silicate to sodium hydroxide is 1.7 and the concentration of sodium hydroxide is varied from 6M to 12M. Concentration of 10M NaOH promotes the best properties of mortar by achieving the greatest compressive strength. Substitution of mineral admixture also influences strength performance of AAS mortars. The mortar with 20% calcium carbonate demonstrates the maximum compressive strength. The used of alkaline activation system is the best method to prepare industrial byproduct concrete. Moreover, alkali activated product itself gains superior properties which lead to the system become the most interesting method to produce sustainable concrete.

Chemical and Physical Characterization of Fly Ash as Geopolymer Material

“…[13] The research conducted by Tajunnisa stated that more irregular shape particles required more water in mixing geopolymer paste [8].With the purpose of produce geopolymer paste, water content is represented by alkali solution. It is also concluded that concentration and composition of alkali solution plays an important role in developing mechanical properties of geopolymer paste [20][21][22].…”

Recycling of Precast Concrete Waste Sludge With Paper Mill and Biomass Ashes for Lightweight Granulated Aggregate Production

“…The results of the mechanical properties (Figure 4) show that low concentration sodium hydroxide -Torgal et al, 2008;Thunuguntla and Gunneswara Rao, 2018). However, an excess of alkali has detrimental effects hindering the formation of the alkali activation reaction products (Pacheco-Torgal et al, 2008;Hashim et al, 2015).…”

Improving Geopolymer Characteristics with Addition of Poly-Vinyl Alcohol (PVA) Fibers

“…Using fly ash as a choice in making geopolymer technology is one of many inventions to decrease by-product piling in power plants. Geopolymer binder is formed by mixing fly ash with alkali solution, where sodium hydroxide (NaOH) with a concentration of 8 to 16 molar is applied [3,4]. Other than NaOH, sodium silicate (Na2SiO3) is also mixed to enrich soluble silica in the binder system, where the fly ash usually contains less reactive silica than other alumina-silica source e.g.…”