Performance and mechanism analysis of natural fiber-reinforced foamed concrete

This study examines the microstructure and mechanical properties of foamed concrete modified by natural fibers (basalt, coir, and sisal) in concentrations ranging from 0.15 % to 0.45 %. The objective was to develop high-performance natural fiber-reinforced foamed concrete (NFRFC). Comprehensive experimental analyses were performed, including assessments of micromorphology, phase composition, water absorption, compressive and flexural strength, as well as durability. The results indicate that coir fibers markedly enhance the compressive strength of NFRFC, outperforming sisal and basalt fibers. Optimal compressive strength, an increase of 42.19 % over the control, was achieved with a coir fiber content of 0.3 %. Conversely, excessive fiber addition was found to enlarge pore size and connectivity, adversely affecting the NFRFC's microstructure. All fiber variations significantly improved the flexural properties, with basalt fibers providing the most effective reinforcement. Additionally, while freeze-thaw and wet-dry cycles generally diminished the performance of foam concrete, the inclusion of natural fibers like coir mitigated micro-cracking and enhanced durability. The study suggests incorporating suitable quantities of coir or sisal fibers into foamed concrete to achieve durable, high-performance NFRFC suitable for various engineering applications.