Influence of Hybrid Fibers on Flexural Properties of Ultra High Toughness Cementitous Composites with Nano-SiO₂

Abstract:

Ultra High Toughness Cementitous Composites (UHTCC) is a unique class of the ultra-ductile fiber reinforced cementitious composites. To meet the increasingly high requirements for materials in the construction, nanoSiO₂, polyvinyl alcohol (PVA) and steel (ST) fibers were added into UHTCC to improve the mechanical property and control the crack width. Multiple effects of nanosilica and hybrid fibers on the flexural properties of UHTCC under three-point bending are evaluated. The results show that nanoSiO₂ can increase flexural strength of UHTCC while equivalent deformability is guaranteed. When the addition of nanoSiO₂ is 5%, the highest flexural strength is 15.77MPa. Moreover, hybrid steel-PVA fibers effectively mitigate negative influence from nanoSiO₂ which induce the wider cracks of UHTCC as the stronger matrix. Comparing with mono fiber composites, hybrid fibers composites exhibit remarkably higher flexural strength and slightly lower deformation. The best performance are 24.85MPa and 2.34% at maximum volume of hybrid fibers.

• Periodical: Key Engineering Materials (Volumes 645-646)
• Pages: 411-415
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.645-646.411
• Online since: May 2015
• Authors: Xiang Gao, Qing Hua Li*, Shi Lang Xu
• Keywords: Flexural Properties, Hybrid Fibers, Nano-SiO₂, UHTCC

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