Performance Evaluation of Cashew Nutshell Ash Aiming Their Use in Cement Composites

Abstract

Every year, the agro-industrial sector generates a lot of waste by-products that, due to poor management and a lack of awareness of their values, present risks to the environment, society, and economy. One of the promising substitute materials for cement that can be used in the construction industry is cashew nut shell waste. Thus, the ash from cashew nutshell was investigated in this work. Since they are a byproduct of the energy generation process, ashes maintain a significant position among the agro-industrial wastes. Because most ashes include pozzolanic activity, they can be utilized in place of cement to create low-cost composites with less energy waste. The current study uses Thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTGA), X-Ray Fluorescence Analysis (XRF) and X-Ray diffraction (XRD). It is concluded that using CNSA in concrete is beneficial in reducing environmental and sustainability issues. CNSA concrete is advantageous in environments with high sulfate concentration. It was found that the total amount of silicon oxide (SiO₂), aluminum oxide (Al₂O₃), and iron oxide (Fe₂O₃) obtained in CNSA. An amorphous structure is indicated by the broadened peak that occurs in the XRD pattern at about 2θ=24^○. Increasing the activation temperature tends to cause the activated carbon to graphitize. Chemical testing revealed a low silicon (SiO2) content, and the analysis of the CNSA-soluble extract revealed the presence of heavy metals.