Valorization and Utilization of Nano-CaO from Eggshell Waste in Concrete Composites for Sustainable Structures

Sequel to sustainability and the rise in the cost of building materials, the search for affordable and cheap building materials has been on the increase, especially in developing countries. Consequently, this research investigates chemical, strength and workability properties of Bamboo Leaf Ash (BLA) and Egg Shell Powder (ESP) concretes. Bamboo leaves and Eggshells (ESs) were processed to obtain BLA and Nano - CaO. The X-ray fluorescence (XRF) technique was used to analyze the chemical compositions of BLA and ESP. The cement (Ordinary Portland cement) was replaced at 15% in weight for the ratios (40:60, 45:55, 50:50 and 55:45) of BLA: ESP respectively. The cubes were crushed to get the various compressive strength of the concrete at different curing days. XRF analysis shows that BLA is formed by silica in concentration level of about 68% and ESP has a high concentration of CaO (89.2%), which contributes to strength development of concrete. At 28day curing, the 40:60 replacement gave optimal strength of 25.90 MPa slightly above the 0% replacement of 25.59 MPa. Samples with 55:45 ratios produced highest slump at 60mm. Based on the findings, it is concluded that ternary blend of these composite materials can achieve enhanced concrete properties for sustainable constructions. Keywords: Sustainable concrete, waste management, supplementary cementitious material, recycled materials.