Flexural Properties of Coconut Fiber Hybrid Multi-walled Carbon Nanotube Reinforced Foam Concrete

Abstract

In this study, the enhancement mechanism of flexural properties of foamed concrete was systematically discussed by using a hybrid system of multi-walled carbon nanotube (MWCNT) and coconut fiber. The study is divided in two parts. Firstly, the effect of MWCNT content and foaming method on the flexural strength of foamed concrete was studied. It was found that using a physical foaming process, the addition of MWCNT content in the range of 0.08 wt.% to 0.17 wt.% better improved the flexural strength compared to chemical foaming. But both methods reach their maximum strength at 0.2 wt.% with improvements around 110–119% compared with the reference group (without reinforcements). Secondly, the load-deflection curve characteristics of foamed concrete reinforced with fixed coconut fiber content and various MWCNT dosages were analyzed. By using a piecewise model for the load-deflection curve, it was found that the experimental data were well predicted (R² > 0.98), especially when the reinforcement content is 0.2 wt.%. In addition, the strengths of the foam concrete prepared in this study are higher than for similar studies in the literature. In summary, MWCNT-coconut fiber composite system can effectively improve the flexural properties of foamed concrete, providing a strong basis for the high-performance design of lightweight and sustainable building materials.