Effects of cold-bonded artificial aggregate properties on the behaviour of concrete

Abstract

The study investigates the use of artificial aggregates (AAs), specifically manufactured from ground granulated blast furnace slag (GGBFS) and ordinary Portland cement (OPC), to mitigate environmental harm caused by illegal quarrying due to the scarcity of natural aggregates (NAs). A cold-bonded pelletization technique was employed to produce five types of AAs with varying proportions of GGBFS & OPC as 82.5:17.5, 85:15, 87.5:12.5, 90:10, 95:5. The AAs with maximum OPC content exhibited a density of 1298 kg m⁻³, water absorption of 4.8%, and crushing and impact values of 28.6% and 26.3%, respectively. The impact of these AAs on concrete properties was assessed, revealing that AAs facilitated the production of workable concrete with low-density ranges between 1700–2337 kg m⁻³. Despite a decrease in concrete strength with higher AAs content, structural requirements were met, demonstrating AAs’ potential to effectively substitute natural coarse aggregates (NCAs). The concrete microstructure confirmed the formation of a strong interfacial transition zone (ITZ) and strength-developing cement-hydrated products. This research underscores the scientific contribution of AAs to address aggregate scarcity sustainably and recommends its application in structural elements by experimental validation.