Eggshell-Derived Calcium-Rich Powder for Sustainable Cementitious Composites: A Critical Review of Mechanical Properties, Durability, Microstructure, and Environmental Implications

Abstract

This review paper investigates the role of eggshell powder (ESP) as a partial replacement for cement in M35-grade concrete. The cement was replaced with ESP at varying proportions of   0%, 2.5%, 4.5%, 7.5%, 8.5%, and 11% by weight. The study highlights improvements in workability, compressive strength, and tensile strength, particularly at lower replacement levels. Maximum compressive strength was observed at 4.5% ESP, with a 27.6% improvement over the control. The rapid growth of industrialization has led to pressing concerns regarding the disposal of biodegradable and industrial waste. One such waste product, eggshells—commonly discarded in large volumes by the food industry including hatcheries, bakeries, and fast-food outlets— poses environmental risks if not effectively managed. Rich in calcium-based compounds, these eggshells offer potential as a sustainable additive in construction materials. This research investigates the feasibility of incorporating eggshell powder (ESP) as a partial substitute for cement in M35-grade concrete. Since traditional cement production is highly energy-intensive and a major contributor to carbon dioxide emissions, replacing a portion of it with ESP could significantly reduce environmental damage. This strategy not only promotes the recycling of waste materials but also helps preserve natural limestone resources and decrease the overall ecological footprint of concrete production. This paper consolidates experimental results and discusses the feasibility of ESP as a sustainable cement substitute in concrete applications.