A novel self-hardening cementitious material by the self-activation of glass powder

The high carbon emissions associated with alkali activators used in ground granulated blastfurnace slag (GGBS) based alkali-activated materials bring a controversy about their sustainability. This study investigated the self-hardening behavior of three glass powders (GPs) in the activator-free self-activating cementitious materials. The mechanisms of the self-activation of the different GPs were revealed. The experimental results showed that the dissolution of the GPs can release Na⁺ to form an alkaline solution. Due to the self-activation nature of the GPs, the hydration of the paste was promoted with the replacement of GGBS by GPs. As a result, the self-activation of 100% fluorescent lamp GP can achieve a satisfactory compressive strength (30.8 MPa). The main hydration product was N-C-S-H gel, which was similar to that in normal alkali-activated materials. The TGA, FTIR, and NMR results indicated that the GGBS can be activated by the GPs without the addition of external alkalis activators. The dense microstructure contributed to the strength development of the self-hardening cementitious material.