Physico-mechanical and chemical performance of Portland cement modified with eggshell powder for sustainable construction

Abstract

Cement is one of the most used materials in the construction industry. Its production contributes about 8% to the global emissions. This study explores the use of eggshell powder (ESP) that contains over 80% calcium carbonate (CaCO 3 ) as a partial substitute for ordinary Portland cement (OPC), such as Types B and D, to substitute limestone within the cement matrix. The physical (consistency and setting time), compressive strength, and chemical (Scanning Electron Microscope with Energy Dispersive Spectroscopy, (SEM-EDS), and X-ray Diffraction (XRD), X-ray fluorescence (XRF)) properties were evaluated against British, Indian, and established standards in the literature. The results showed that cement consistency (31–35%) and setting times were within acceptable limits according to BS EN 197-1 (initial ≥ 60 min) and IS 8112 (initial ≥ 30 min, final ≤ 600 min). The mechanical strength of the samples exceeded the required strength (42.5 N/mm 2 ) recommended by the British Standards, except for samples B10N and D10N, which showed strength reductions of 8.4% and 12.3%, respectively. The SEM-EDS and XRD analyses confirmed a high CaCO 3 content in the samples. The study suggests that incorporating ESP into OPC should not exceed 5% by weight, as higher proportions could negatively impact the cement’s physical and strength properties. This approach will promote environmental sustainability by using agro-waste while ensuring the cement remains suitable for construction.