Evaluating the availability and carbon footprint of agricultural waste ashes: a strategy for achieving sustainable cement production in India

Abstract

The effective reuse of agricultural waste ashes as a sustainable alternative for cement in blended concrete enables a substantial reduction in carbon dioxide emissions. However, agro-waste ashes are disposed of as waste which causes severe air and land pollution. To encourage the widespread adoption of agricultural waste ashes as alternative cementitious materials, it is required to assess their performance with respect to other well-established alternative by-products. Thus, the present study covers a comparative assessment of the performance of agricultural waste materials, including rice husk ash, sugarcane bagasse ash, bamboo leaf ash, and banana leaf ash, with respect to other prospective alternative wastes such as fly ash, slag, metakaolin, silica fume, cement kiln dust, ceramic waste powder, marble waste powder, glass powder, and wood ash, as pozzolans in blended concrete. Besides, this study provides the distribution of these alternative materials across several regions in India and explores their comparative performance in blended concrete. Optimum replacement levels of rice husk ash, sugarcane bagasse ash, banana leaf ash, and bamboo leaf ash are 20, 20, 10, and 10%, respectively. Due to the carbon-rich fibrous structure of agricultural waste ashes, the loss of ignition of agricultural waste ashes is higher than the industrial by-products. Moreover, the permeability of agricultural waste ashes based blended concrete is significantly lesser than the control concrete. Incorporating agricultural waste ashes as pozzolans in blended concrete leads to a significant reduction in carbon dioxide emissions offering both economic and environmentally sustainable construction solutions.