Assessing the sustainability and cost-effectiveness of concrete incorporating various fineness of eggshell powder as supplementary cementitious material.

The eggshell powder (ESP) has been used as a partial cement replacement to reduce the cement content in concrete production. According to recent estimates, cement production contributes to 7% of global Carbon Dioxide (CO) gas emissions. However, most of the studies so far have focused on the mechanical strength aspect of the concrete incorporating ESP; however, there is a lack of information on the influence of ESP on the sustainability of concrete in terms of embodied carbon and eco-strength efficiency. Therefore, this study aims at determining the influence of ESP on the sustainability and cost of an M40 grade concrete when different fineness ESP (50 µm and 100 µm) is utilized as partial cement replacement. The sustainability was assessed in terms of embodied carbon and eco-strength efficiency, while the cost-effectiveness was determined in terms of the overall cost of concrete and cost to produce unit compressive strength. It was observed that the control M40 concrete mix achieved a total embodied carbon of 482.88 kgCO/m. With 5 to 15% ESP of 100 µm fineness, the total embodied carbon was successfully reduced, ranging from 3.86 to 11.60%. While 5 to 15% of 50 µm fineness, the reduction ranged from 3.69 to 11.10%. The 50 µm fineness ESP exhibited slightly lower eco-strength efficiency compared to 100 µm fineness ESP; however, both achieved relatively higher eco-strength efficiency. In terms of cost, the inclusion of ESP resulted in a significant reduction in overall cost and was cheaper to produce 1 MPa compressive strength.