Basic parameters test and 3D modeling of bond between high-strength concrete and ribbed steel bar after elevated temperatures.

This paper presents basic parameters test and an efficient numerical model for the bond between reinforcing bars and concrete after elevated temperatures. The chemical adhesive and friction coefficient are measured by self-designed setups, and the variation law of the parameters is summarized. In the 3D modeling, bar-to-concrete interface has been modeled by means of an explicit discretization of the bar ribs. Surface-to-surface contact pair elements are employed for the interface, and the tangential contact behavior is elastic-plastic with a Coulomb-type friction model. Comparison between experimental and numerical results shows that the proposed model describes the behavior of steel bar relatively well in the pull-out process after elevated temperatures. The 3D modeling makes up some deficiencies of macro pull-out test, such as the detailed stress distributions and crack patterns. [ABSTRACT FROM AUTHOR]