Influence of nanoparticles additions on the bond between steel fibres and the binding paste. (1st October 2017)

• Record Type: Journal Article
• Authors: Carmo, R.N.F.; Costa, H.; Júlio, E.
• Is Part Of: Construction & building materials. Volume 151(2017)
• Page Start: 312
• Page End: 318
• Publication Date: 2017-10-01
• Subjects: Nanoparticles -- Steel fibres -- Binding paste -- Fibres' bond; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2017.06.085
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Evaluation the influence of nano-SiO2, nano-Al2 O3 and nano-ZnO on fibres-to-binding paste bond. Innovative pull-out test designed to record the bond-slip curves of fibres using traditional equipment. Adding nanoparticles to the binding paste is more effective than applying on the fibres' coating. Nano-Al2 O3 increases slightly the bond strength and nano-ZnO has a negative effect on the bond strength. Abstract: In the last decades, steel fibres have been widely used to reinforce the binding paste of concrete, mainly aiming at preventing/controlling cracking, by significantly increasing the (low) tensile strength and deformation capacity of current concretes. In this scope, the bond between steel fibres and the binding paste is of paramount importance. Following the more recent development of nanoparticles, several studies have been conducted to assess how they can enhance the properties of concrete mixtures. An experimental program was defined and conducted to analyze the influence of nanoparticles additions in the fibre-to-paste bond strength. A new pull-out test for monitor the fibres' slip versus the applied load was specifically designed in this scope, using current equipment, and thirty-six specimens were tested up to failure. It was concluded that it is more effective to add nanoparticles to the binding paste than to add these as fibres' coating and the fibres' anchorage, namely the hooks at both ends of the fibres, plays a much more significant role on the fibres-to-paste bond strength than the nanoparticles addition.