Optimum pretreatment of corn stover ash as an alternative supplementary cementitious material

Abstract

As sustainable construction practices become more popular, researchers are looking into using readily available and inexpensive agricultural waste materials as a supplementary cementitious material. This study investigates the impact of various pretreatment methods on the chemical composition, crystal structure, morphology, and cost of producing pretreated corn stover ash collected from four different sources in the U.S. This study also evaluates the performance of mortars and pastes containing treated corn stover ash through tests such as compressive strength, flow measurement, calorimetry, and thermal analysis. In addition, thermodynamic modeling is used to predict the phase composition, chemical composition of the pore solution, pH, and electrical resistivity of pastes made with selected pretreated corn stover ashes. The results suggest that acid pretreatment is the most effective and economical method for improving the quality of corn stover ash and that it removes a significant amount of alkalis from the raw material. The simulation of the reaction between cement and the pretreated corn stover ash was confirmed by the experimental results, indicating a marked enhancement in the pozzolanic activity and chemical and physical characteristics of the system.