Enhancement of the mechanical properties of green concrete bricks modified with nanomaterials from cement kiln dust and red brick dust

Abstract

This study presents a methodology for investigating the effect of adding nano cement kiln dust (NCKD) and nano red brick dust (NRBD) on the mechanical properties of concrete bricks. Cement kiln dust and red brick dust were processed into nanomaterials and incorporated into concrete brick mixes as partial replacements for cement at varying percentages: 0%, 10%, 20% and 30%. The research evaluated the fresh and hardened properties of the brick mixes. The workability of the fresh mixes was assessed using the slump test. The hardened properties, which included compressive strength, flexural strength and shrinkage, were measured after 28 days. Results indicated that replacing up to 10% of the cement with NCKD and NRBD led to improvements in the mechanical properties of the bricks. Higher replacement levels of 20% and 30% exhibited a slight increased effect on these properties. In particular, the replacement level of 10% resulted in a 21.6% increase in compressive strength and a 37.8% increase in flexural strength compared with the control bricks (with 0% replacement). In addition, the use of nano additives contributed to reduced shrinkage and improved microstructure by filling voids in the bricks. The findings of this research support the development of ‘green’ concrete bricks with enhanced mechanical properties, reduced environmental effects, and increased sustainability in the construction industry.

Keywords

• Nano cement kiln dust (NCKD)
• Nano red brick dust (NRBD)
• Compressive strength (CS)
• Flexural strength
• Dry shrinkage
• Nano cement bricks (NCMs)