The hydration and microstructure characteristics of cement pastes with high volume organic-contaminated waste glass powder

This study investigates the influence of the organic-contaminated waste glass powder-filter glass on cement hydration and the microstructure characteristics of the hydration products. In order to study the influences of organic contamination, treated (washed) glass powder was used as reference addition. The incorporation of filter glass powder results in longer induction periods and lower reaction intensity compared to the samples with washed glass. The addition of chemical accelerators such as CaCl2, nanosilica and microsilica can significantly improve the hydration of samples containing high volumes of filter glass powder. The organic contamination shows a negligible effect in terms of hydration products identified by XRD analysis. In mixtures with high volume filter glass powder (70%), the formation of calcium hydroxide was delayed at 3 and 7 days. Samples containing more than 50% waste glass present a higher pore volume in pore sizes lower than 15 nm and lower pore volume between 20 and 50 nm. It was observed from the SEM analysis that the organic contamination may slow the pozzolanic reaction of glass particles in mixes with 70% filter glass. (C) 2018 Elsevier Ltd. All rights reserved.