Properties of ultra-high performance geopolymer concrete incorporating recycled waste glass

Abstract

One of the advantages of geopolymer technology is the ability to recycle a variety of wastes. In this paper, waste glass was incorporated into ultra-high performance geopolymer concrete (UHPGC). Recycled waste glass replaced fine sand in various ratios in UHPGC. Several mixtures were prepared by replacing natural sand with 0 %, 7.5 %, 15 %, and 22.5 % of waste glass (WG). The prepared samples were submerged in 2 % H2SO4 and 5 % MgSO4 solutions. Furthermore, the samples were subjected to high temperatures (200–800 °C) for 1.5 h. The effect of the WG on UHPGC’s flowability, strength, durability properties, and elevated temperature resistance was examined. The experimental results demonstrate that the flowability of the mixture was increased by glass content. Compressive strength was reduced from 126 MPa to 121 MPa for the substituted 22.5 % natural sand by WG at ambient curing. After 120 days of exposure, the strength loss of the control mix and samples containing 22.5 % WG submerged in MgSO4 solution was found to be 5.3 % and 1.16 %, respectively. While submerged in H2SO4, the control mix and samples with 22.5 % WG lost 7.7 % and 1.83 % of their strength, respectively. Additionally, mixtures incorporating WG showed better thermal stability as compared to the control mixtures after high temperature exposure. Finally, after being heated, microscopic studies showed that mixtures with WG had less microcracks and a better transition zone between the geopolymer paste and the fine aggregate.