Title: Influence of Bond Behavior on the Cross Sectional Forces in Flexural RC Members Strengthened with CFRP

Author(s): G. Zehetmaier and K. Zilch

Publication: Symposium Paper

Volume: 230

Issue:

Appears on pages(s): 529-542

Keywords: bond behavior; bond coefficients; cross-sectional forces; externally bonded reinforcement; flexural members; numerical model; tension stiffening

DOI: 10.14359/14852

Date: 10/1/2005

Abstract:
In strengthened RC members the distribution of cross sectional tensile forcesis affected by the significant differences in bond behavior of the reinforcement layers.As the tensile forces in the externally bonded reinforcement is the essential input valuefor bond verification for example at the end anchorage, the detailed knowledge of thedistribution of forces in cracked sections is of fundamental importance. In this paperthe common models to describe the interactions in tensile members are summarizedand an advanced numerical model based on nonlinear bond stress-slip relationships forstrengthened flexural members is presented. On the basis of experimental resultscombined with parametric studies, the effects of various parameters – for example theaxial stiffness of CFRP, the diameter of internal rebars or the concrete compressivestrength – on the interactions between the different reinforcement layers areexamined. For practical design bond coefficients for a simplified calculation of crosssectional tensile forces are proposed.