Title:
Analytical Bond-Slip Model of Steel Bar to Concrete Under Confinement (Prepublished)
Author(s):
Fangduo Xiao, Shikun Chen, Jizhong Wang, Dongming Yan, and Junlong Yang
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
analytical model; bond-slip response; fictitious crack; FRP-stirrup dual confinement; radial stress
DOI:
10.14359/51749099
Date:
7/31/2025
Abstract:
The bond property between deformed bars and concrete plays a significant role in the safety of construction. Numerous database-dependent empirical models are proposed to evaluate the bond behavior without considering the effect of additional confinement, whose application range is quite limited as a result of unstable accuracy. In this paper, a new model was established based on the thick-walled cylinder model and fictitious crack theory, which can predict bond strength and bond-slip response with fiber-reinforced polymer (FRP)-steel confinement. The effects of various factors on the bond behavior, such as concrete strength, concrete cover, rebar diameter, bar surface geometry, and FRP/steel confinement, were comprehensively discussed. According to the radial crack radius, the radial stress and displacement induced on the bond interface can be calculated, and thus the analytical formulae of bond strength and slip were respectively developed in conjunction with deformed bar surface geometry. Finally, a new analytical model was proposed, which can simulate the bond-slip curves of the specimens with different confinement levels, covering unstrengthened, FRP-strengthened, stirrup-strengthened, and FRP-stirrup dually strengthened specimens. Compared with existing models, the proposed model can provide better agreement with existing test results.