Influence of elastobar and zycoprime nanochemicals on concrete properties with coarse aggregate partially replaced by periwinkle shell

Abstract

Solid waste management, particularly of periwinkle shells, poses a persistent environmental challenge in Nigeria's riverine regions. While past studies have explored the use of periwinkle shells in concrete, limited attention has been given to the potential benefits of nano-chemical additives. This study investigated the properties of concrete mixed with periwinkle shells and nano-chemicals (Elastobar and Zycoprime) enhancing its performance. Periwinkle shells were obtained from Ilaje, Lagos State, and subjected to particle size distribution analysis to determine their coefficient of curvature (Cc) and uniformity coefficient (Cu). Their porosity, permeability, specific gravity, aggregate impact value (AIV), and aggregate crushing value (ACV) were determined according to standard methods. Concrete of grade M30 was prepared with partial periwinkle shell replacement at 0, 20, 40, 60, 80, and 100% aggregate. Tests included slump, bulk density, compressive strength, tensile strength, and water absorption at 28 days. The microstructure of the optimal mix was analyzed using Scanning Electron Microscopy (SEM). The periwinkle shell had Cu (1.31), Cc (1.80), porosity (45%), permeability (1.2 × 10?² cm/s), specific gravity (2.68), AIV (40.2%) and ACV (37.6%). The slump, bulk density, compressive strength for slumps above 20 mm, tensile strength, and water absorption ranged from 51.56 to 76.12 mm, 2345.78 to 2360.25 kg/m³, 10.91 to 42.10 MPa, 1.49 to 4.50 MPa, and 3.6 to 26% respectively. SEM images revealed a denser microstructure with fewer voids in the optimal mix. Incorporating Elastobar and Zycoprime with periwinkle shells in concrete enhances its performance, making it suitable for mass concrete and load-bearing applications.