Characteristics of volume change and heavy metal leaching in mortar specimens recycled heavyweight waste glass as fine aggregate

Industrial waste, such as heavyweight waste glass, has become a global concern in terms of environmental safety and resource recycling. The reuse and recycling of heavyweight waste glass are necessary from the viewpoint of environmental protection. At the same time, concrete, three-quarters of which consists of aggregate, is one of the most widely used infrastructure materials, and it is being exhausted. The heavyweight waste glass being is considered as the most suitable substitute for aggregate due to its physical characteristics and chemical composition. In this study, to evaluate whether heavyweight waste glass could be as a concrete material, we carried out drying shrinkage, expansion by alkali-silica reaction (ASR) and heavy metal leaching of mortar. We found that when the heavyweight waste glass substitution ratio increased, the drying shrinkage decreased. Furthermore, the existing models predicted the experimental results, inversely. However, the expansion of ASR mortar gradually increased with an increase in the substitution ratio of heavyweight waste glass. When fly ash 20% or blast furnace slag 50% was mixed in mortar specimens, the ASR expansion could be controlled within the permitted limit of 0.1% at 14 days by the ASTM 1260 criteria. Moreover, the leached concentration of As, Cd, Cu and Hg from the mortar were detected below the criteria specified in drinking water regulatory levels, however, further investigation is needed to determine the leaching characteristics of Pb and Cr according to heavyweight waste glass substitution ratio in mortar specimens. Conclusively, the overall test results of this study have demonstrated that it may be feasible to utilize heavyweight waste glass as fine aggregate in mortar specimens. (C) 2018 Elsevier Ltd. All rights reserved.