Experimental Investigation on the Engineering Properties of a Novel Geomaterial Containing Bottom Ash, Blast Furnace Slag and EPS Beads

Abstract

This study presents the experimental findings on a Novel Geomaterial (NGM) developed using bottom ash as the primary constituent material. The NGM was made by mixing bottom ash with blast furnace slag and some expanded polystyrene beads, and it relied on ordinary Portland cement as the binder for real. Five different EPS bead contents 0.2%, 0.4%, 0.6%, 0.8% and 1.0% were considered as mix ratios. Blast furnace slag was incorporated at three replacement levels of 4%, 8%, and 12%. In addition, two cement to bottom ash weight ratios, 20% and 30%, were adopted in the study. The experimental program looked at compressive strength, the stress-strain behavior, density, plus the initial tangent modulus for the NGM while using various mix designs and different curing times. The researchers performed compressive strength tests on 70 mm cube samples that were cured for 7 days, 14 days, and 28 days. The results indicate that compressive strength consistently improved with increasing slag content, higher cement dosage, and longer curing duration across all mix ratios, with recorded strengths ranging from 135 kPa to 1020 kPa. The stress–strain behavior exhibited a nonlinear relationship, with compressive stress increasing progressively with axial strain. Furthermore, the density of the prepared NGM decreased from 993 kg/m³ to 611 kg/m³ depending on the mix ratios, while the initial tangent modulus showed a positive correlation with compressive strength. The findings show a kind of manageable trade-off between density and short-term compressive behavior, but the whole thing around environmental sustainability and field readiness is still up in the air, mostly because embodied carbon assessment, leachability checks, durability testing, and wider field-scale validation still need to be done.