Development of sustainable cementitious composites using agricultural waste and seashells

Abstract

This study investigates the development of sustainable cementitious composites by partially replacing ordinary portland cement (OPC) with agricultural waste ashes such as rice husk ash, groundnut shell ash, coconut shell ash, and bamboo leaf ash, along with seashell ash. The aim is to minimize environmental impact and promote low-carbon construction practices. The raw materials were cleaned, calcined, and characterized using XRF and FESEM analyses to assess their chemical composition and microstructure. Experimental results revealed that a 70% OPC and 20% agro-waste + seashell ash blend exhibited optimal performance, achieving a 28-day compressive strength of 0.71 MPa and a tensile strength of 0.507 MPa, suitable for non-structural applications such as paving blocks and tiles. The high silica and calcium oxide content enhanced pozzolanic reactivity and matrix densification. These composite reduced CO₂ emissions by up to 15%, provided effective waste valorization, and offered cost efficiency. The findings highlight its potential as an eco-friendly, sustainable alternative to conventional cement for future green infrastructure.