Alkali-Activated Materials Incorporating Active and Inactive Fillers: Strengths of Slag/Waste Crushed Stone Powder-Based Systems

In order to avoid the disadvantages of alkali-activated slag and to utilize coal fly ash (FA), much research has been done on geopolymer (GP) or broadly called alkali-activated material (AAM), which uses a blend of ground granulated blast furnace slag (GGBFS) and FA as amorphous active fillers. However, in order to achieve carbon neutrality, coal-fired power generation will inevitably be reduced, thus the AAMs using FA may face a lack of FA in the future. To develop the AAMs using a blend of active and inactive fillers as precursors, and to find an alternative to FA, the author investigated the strengths of AAM using a blend of GGBFS and siliceous or limestone crushed stone powder (CSP). The latter is a by-product of crushed stone aggregates. The experimental results show that although CSP is an inactive filler, it can replace FA to produce the desirable AAMs and even high-strength AAMs, and the alkali-activated GGBFS/CSP is possible to meet the quantitative and qualitative needs of construction industry for binding material.