Mechanical, durability, and microstructural characteristics of rice-straw-ash-based clay bricks: a sustainable approach to utilize biomass-based power plant waste

Abstract

Burnt clay bricks are currently facing environmental issues as a result of the increasing depletion of natural clay resources. Recently, researchers have investigated the possibility of using a variety of wastes to produce clay-based bricks. Considering a similar approach, an experimental study has been conducted using agricultural waste, i.e., rice straw. In the study, the effect of the addition of rice straw in the form of ash on the performance of clay-based bricks has been evaluated by replacing the clay content of the mix with different proportions (2%, 4%, 6%, 8%, and 10% by weight) of ash. Apart from the preliminary characterization of materials, various physical, mechanical, and durability characteristics of ash-based bricks were determined. Advanced characterization techniques such as scanning electron microscopy and X-ray diffraction have also been utilized to identify/validate the effect of ash addition. The results revealed that the addition of 2% and 4% ash showed 22.25% and 43.82% reduction in strength, respectively, satisfying the requirements prescribed in Indian Standards, i.e., IS 3495 and IS 1077: 1992, for first- and second-class clay bricks. In addition, the microstructure assessments also validated the obtained results, suggesting the produced bricks are suitable for various practical applications in construction practices.