ASR mitigation using binary and ternary blends with waste glass powder

摘要

Alkali silica reaction (ASR), commonly referred to as "concrete cancer", is a major durability problem in concrete structures. ASR is a chemical reaction that occurs between the reactive amorphous silica from the natural aggregates and the alkalis in cement in the presence of moisture. This reaction causes undue expansion and cracks in hardened concrete which over time results in deterioration. The use of supplementary cementitious materials (SCMs) has been proven effective to minimize ASR distress. In this study, a synergistic function of glass powder was evaluated in binary and ternary blends with conventional SCMs (slag and silica fume) for ASR mitigation. The ASR mitigation was evaluated using the accelerated mortar bar test (AMBT) and miniature concrete prism test (MCPT) methods. Additional testing including the flow test, strength activity index (SAL), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive x-ray spectral analysis (EDS) was conducted to examine the pozzolanic activity, microstructural analysis, and chemical composition. The results demonstrated that the use of SCMs along with glass powder reduce ASR expansion substantially. The binary or ternary blends of 20% replacement of glass powder, slag, or silica fume can be utilized for ASR mitigation without compromising other concrete properties. Also, the ternary system containing glass powder with other conventional SCMs performed better compared to individual use of SCMs to mitigate ASR. These results were also supported by the findings of the microstructure and chemical analysis, in which the glass powder and SCMs were found to reduce the cracks due to ASR expansion. (C) 2021 Elsevier Ltd. All rights reserved.