Influence of cellulose nanofibers and metakaolin for sustainable HPC beam-column joints under cyclic loads

ABSTRACT

This research examines the effectiveness of cellulose nanofibers (CNFs) in reinforcing beam-column joints against repeated, reversed stresses (cyclic loading), a crucial factor in earthquake resistance. By exploring various combinations of silica fume and CNF content, the study aimed to develop a high-performance concrete mix. The hypothesis centered on enhancing joint ductility, the ability to absorb energy, through the combined effect of CNFs with varying lengths and volumes alongside silica fume. The results were remarkably positive. When CNFs were incorporated, the joints exhibited significant improvements in multiple areas: deformability (capacity to deform under stress), ductility (energy absorption), and overall ability to dissipate energy during cyclic loading. Furthermore, the CNFs led to a reduction and better distribution of cracks within the joints, while also increasing the load required for initial cracking and the overall load-bearing capacity. These findings highlight the promise of cellulose nanofibers as a reinforcement material for beam-column joints in earthquake-prone structures. Further research can optimize their use with silica fume for broader adoption in sustainable and resilient construction practices.

Keywords:
Cellulose nanofibers; Silica fumes; Metakaolin; Concrete; Cyclic loads