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The pull-out tests for bonding between rebar with inside strain gauges and steel fibre reinforced concrete (SFRC) were carried out to study the bond properties of specimens with varying concrete strengths. Based on the analysis of measured rebar strain, the distribution function of bond stress performed in cubic smooth spline was established. The distribution of bond stress and relative slip in bonded segment was obtained under the action of load at each stage, and the effects of steel fibre and concrete strength on bond properties were further analyzed. The results indicate that with the increasing of volume fraction of steel fibers and concrete strength, the bond stress of bonding specimens next to loaded end is improved and the ultimate bond stress moves to loaded end in general. Meanwhile, the slip at loaded end and free end were reduced. Finally, the bond-slip constitutive model reflecting the interaction process of rebar and SFRC was proposed. [ABSTRACT FROM AUTHOR]

According to the significant deformation and crack propagation of steel fibre reinforced concrete (SFRC) , the expression of hoop elongation for SFRC is established. Furthermore, the calculation method of bond strength between rebar and SFRC is proposed by the elasticity theory, fictitious crack theory and post-cracking softening model. The method is verified by the test results. The effects of relative cover thickness ( ratio of concrete cover to rebar diameter) , crack number and rebar diameter on the relative bond strength (ratio of bond strength to SFRC tensile strength) are analyzed. The results show that the relative bond strength of rebar embedded in SFRC is between plastic solution and partially elastic solution. Within 0. 5%-l. 5% volumetric ratio of steel fibre, the relative bond strength increases with the increase of relative cover thickness and crack number, but reduces with the increase of rebar diameter. However, when the crack number is more than five or the rebar diameter is more than 32 mm, the variations of crack number and rebar diameter have insignificant effects on the relative bond strength. [ABSTRACT FROM AUTHOR]