Assessment of long-term reactivity of initially lowly-reactive solid wastes as supplementary cementitious materials (SCMs)

Recently, due to various reasons, the amount of commercial supplementary cementitious materials (SCMs) available for the concrete industry has depleted and hence a wide range of moderately to lowly active solid wastes are being considered as SCMs. However, using such wastes as SCMs needs an efficient and practical procedure to estimate their long-term reactivity. For this purpose, different mechanical and chemical testing schemes have been specified (e.g. Chapelle test, relative strengths, activity index, modified lime reactivity test, R-3 method) to assess their reactivities. In this study, a wide range of solid wastes including incinerated bottom ash (IBA), different colored soda-lime glass powders, fluorescent lamp glass powder (FLGP) and pulverized fly ash (PFA) were tested to evaluate their reactivities. It was found that there were moderate correlations between 180-day relative strengths (RS180day) of standard mortars and the bound water content or portlandite consumption of the R-3 method. Moreover, the mortar strength values of the modified lime reactivity test were adequately correlated with RS180day of the standard mortars. In comparison, the portlandite consumption values of the Chapelle test had a poor correlation with RS180day. In addition, the studied materials can be classified as lowly-reactive (IBA), moderately-reactive (MGP, BGP, WGP, GGP, BGP, FLGP) and highly-reactive (PFA) SCMs. (C) 2019 Elsevier Ltd. All rights reserved.