An investigation of alkali-activated slag pastes containing recycled glass powder under the effect of elevated temperatures

Herein, the possibility of including recycled glass powder as a promising material in amalgamation with slag to produce new binder materials activated by sodium silicate solution capable to resist high temperatures was studied. Slag was partially replaced with glass powder (GP) at ratios in the range of 0-15%, by weight, with a step of 5%. The powders were activated by a constant concentration of sodium silicate solution. The percentage of water absorption and compressive strength were monitored at the ages of 3, 7 and 28 days. After 28 curing days, the specimens were subjected to severe temperatures in the range of 400-1000 degrees C with a step of 200 degrees C for 2 h and the residual compressive strength was monitored. The results were analysed by X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and energy-dispersive X-ray spectra. The results revealed higher water absorption and lower compressive strength with the incorporation of GP. The incorporation of GP has a negative effect on the compressive strength of alkali-activated slag (AAS) pastes after exposure to 400 and 600 degrees C, whilst it has a positive effect after exposure to 800 and 1000 degrees C.

Automated summary

This study investigated the possibility of incorporating recycled glass powder with slag to produce new binder materials. The results showed that the addition of glass powder affected the water absorption and compressive strength of the materials, and had different effects on compressive strength at different temperatures.