Mechanical behavior of Nano Eggshell Powder and fishnet fiber‐reinforced cement concrete columns under axial compression

Abstract In this study, the mechanical, durability, and structural performance of reinforced concrete using Nano Eggshell Powder (NESP) and Waste Fish Net fibers (WFN) have been evaluated. NESP was used as a partial replacement of cement starting from 0% to 3% by weight of cement, and WFN fibers were used at a constant dosage of 1.5% in M25 grade concrete. The tests that were conducted under the experimental program include compressive strength test, split tensile strength test, flexural strength test, water absorption test, acid resistance test, and axial load tests. Under axial compression, six reinforced concrete columns were tested. Three of these columns were regular RCC columns, while the remaining three were made of fiber‐reinforced nano‐modified concrete. All columns measured 100 mm × 100 mm × 1300 mm. The analysis of NESP by SEM, EDS, XRD, and FTIR showed its microstructure, chemical form, and calcite crystal structure. The results showed the optimum performance of 2% NESP replacement. The compressive strength at 28 days increased to 44.51 MPa, which is 12.5% more than the control mix. The values of split tensile strength and flexural strength improved by 12.4% and 12.5%, respectively. Water absorption was reduced by nearly 19%, and improved resistance against acid attack was noted. Structural testing showed an increase in axial load capacity of 6.8% with restriction of the lateral buckling displacement. Incorporating eggshell waste and discarded fishing nets is a solution for sustainability in waste generation, cement usage, and carbon dioxide emissions.