Production of artificial aggregates by granulation and carbonation of recycled concrete fines

Abstract

There is a growing need to find ways to reuse fine concrete waste from the construction industry. In this study, recycled concrete fines were granulated and used as lightweight aggregates. Ladle slag, a steel industry residue, was used as a co-binder in different ratios (0, 10, 20, and 30%). The materials were blended and granulated, and then the granules were cured in three conditions: ambient condition, humidity chamber, and carbonation chamber. The results showed that the ladle slag content of 30% cured in a humidity chamber produced the strongest granules, with a crushing strength of 127 N, which was 135% greater than a commercial lightweight aggregate. The granules generally had satisfactory density and water absorption with a higher ladle slag content. Carbonation increased the granule strength with a low ladle slag content and decreased the granules’ water absorption. The improved physical and mechanical properties of carbonated granules are attributed to the formation of calcium carbonate during the carbonation process. The granules produced in this study show good potential for use as lightweight aggregates in the construction industry. Graphical abstract

Managing carbon waste in a decarbonized industry: Assessing the potential of concrete mixing storage

“…The potential of incorporating CO2 into concrete is not limited to the acceleration of the natural carbonation reaction in conventional concrete (e.g., Meng et al 2022 ). Another alternative based on the same principle is the accelerated carbonation of recycled aggregates (e.g., Singh et al 2021 ; Kursula et al 2022 ; Torrenti et al 2022 ; Zhang et al 2023 ) prior to the production of recycled aggregates concrete. However, a variety of other options have explored using other concrete components as CO2 absorbers.…”