Integrated performance and carbon emission assessment of self-compacting concrete incorporating calcined zeolite and glass powder

Abstract

The process of manufacturing cement is significantly responsible for causing environmental pollution and carbon dioxide emissions, which require researchers to find environmentally friendly concrete materials. This paper focuses on examining the mechanical performance and carbon footprint emissions associated with self-compacting concrete containing calcined zeolite and glass powder as replacements for Portland cement and natural sand, respectively. Five mixes of SCC with replacements of 0%, 5%, 10%, 15%, and 20% have been made and named SCM, SCGZ1, SCGZ2, SCGZ3, and SCGZ4. The fresh properties were analysed using standard tests for SCC, and the hardened properties were examined by conducting compressive, split tensile, and flexural tests for 7, 28, 90, and 180 days. The statistical validation of the experimentally obtained data was performed by means of Analysis of Variance (ANOVA). The results proved that the use of CZ and GP improved the mechanical characteristics of the SCC mixture as compared to the control mixture. All mixtures were characterized by different levels of mechanical resistance; in particular, SCGZ4 mixture exhibited the maximum value of the compressive strength at 28 days, i.e., 36.48 MPa. The improvement in mechanical properties was provided by the synergistic effect of the pozzolanic and filler effects of both materials, which improved particle packing and densification of the matrix. Embodied carbon analysis confirmed a decrease in carbon footprint from 348 kg CO₂/m³ for the control mixture to 308.1 kg CO₂/m³ for SCGZ4, i.e., by 11.4%. In addition, the carbon intensity index confirmed more than 25% improvement in carbon efficiency.