Improving steel fiber reinforced concrete pull-out strength with nanoscale iron oxide coating

• The paper studies the pull-out strength of nanorods coated steel fibers in concrete.
• The iron nanorods increase the fiber pull-out strength by over 80%.
• The electrodeposition process of iron nanorods is simple and easy to scale up.

Fiber-reinforced concrete (FRC) has been extensively used all over the world for over 40 years. Steel fiber, being the first and most commonly employed reinforcement fiber, is always favored as the uniformly dispersed reinforcement for concrete due to its improvement towards mechanical strength, failure mode and bonding toughness. This article depicts a nanoscale reinforcement of iron oxide coatings on steel fibers prepared by electrodeposition method. The results indicate that pristine Fe2O3 particles, Fe2O3 nanorods and nanosheets were synthesized under different depositing conditions. The nanorod and nanosheet coated steel fibers were embedded in cement mortar for fiber pull-out tests. Corresponding pull-out tests revealed that iron oxide coating showed a strength enhancement up to 82% compared to the conventional fiber reinforced cement mortar samples.