A Study on Partial Replacement of Cement with Eggshell Powder (Esp) and Fine Aggregate with Robo Sand in M30 Concrete

G Prema Swathi#1,Nathipam Kumar Siva Venkata Sunil*2, Muliki Venkata Appa Rao#3,,Ayinavilli
Laxman#4, Md Zeeshan Khan#5
#1 Assistant Professor, Department Of Civil Engineering, Godavari Institute Of Engineering And Technology
(Giet), Rajahmundry, Andhra Pradesh.
#2-5 B.Tech, Student, Department Of Civil Engineering, Godavari Institute Of Engineering And Technology
(Giet), Rajahmundry, Andhra Pradesh.

Abstract:The construction industry is a major contributor to environmental degradation due to the excessive use of natural resources such as cement and river sand. Cement production generates significant carbon emissions, while uncontrolled extraction of river sand leads to ecological imbalance. This study focuses on developing sustainable concrete by partially replacing cement with eggshell powder (ESP) and fine aggregate with manufactured sand (robo sand). Eggshellpowder, a bio-waste material rich in calcium carbonate (CaCO₃), was used as a cement replacement at levels of 0%, 3%, 6%, 8%, 10%, 12%, and 15%, while river sand was replaced with robo sand at proportions of 0%, 50%, and 100%. Concrete specimens were prepared and tested for workability, compressive strength, and split tensile strength at curing periods of 7, 14, and 28 days. The workability of concrete was assessed using the slump test, which showed a gradual decrease in slump values with increasing ESP and robo sand content due to higher water demand and angular particle characteristics. However, all mixes remained within acceptable workability limits for structural applications. The mechanical properties indicated that the inclusion of ESP improves the microstructure of concrete by acting as a filler material and enhancing particle packing. Robo sand further contributes to strength improvement due to better interlocking between particles. The optimum performance was observed at 10% ESP and 100% robo sand replacement,achieving a maximum compressive strength of 41 MPa at 28 days. Beyond this level, a reduction in strength was observed due to decreased cementitious content. The study concludes that the combined use of ESP and robo sand can produce sustainable and high-performance concrete, reducing environmental impact and promoting eco-friendly construction practices..
Keywords:Eggshell Powder (ESP), Robo Sand, Sustainable Concrete, Compressive Strength, Flexural Strength, Split Tensile Strength, M30 Concrete