ASR potential of alkali-activated soda-lime glass powder in the absence of calcium sources

This study aims to investigate the reaction products of alkali-activated soda-lime glass powder (SLGP) in the presence of calcium sources. To that end, SLGP, blast furnace slag (BFS), and their mixtures were activated using a solution mixed with sodium silicate and sodium hydroxide. To demonstrate their macroscopic behaviors, such as strength development and swelling capacity, hardened synthetics were analyzed using mercury intrusion porosimetry, X-ray diffraction, thermogravimetry, Fourier-transform infrared spectroscopy, scanning electron microscopy, electron dispersive spectroscopy, and nuclear magnetic resonance. The results show that the activation of SLGP with BFS significantly reduced the compressive strength of the synthetics and formed alkali–calcium-silicate hydrates (N-(C)–S–H gels) as binding substances, which had morphological and chemical similarities to swellable alkali–silica reaction (ASR) gels. However, a combination with the BFS transformed the SLGP-products into cementitious C-(N)-A-S-H gels and mitigated not only strength loss but also the swelling phenomena. Based on these results, incorporating SLGP within 50% of the BFS-based synthetics is recommended.