DE-BONDING MODEL AND SENSITIVITY ANALYSIS FOR DEFORMATIONAL RESPONSE OF ANCHOR BARS

Abstract

The effect of the interface properties such as stiffness and the strength on the
pull-out behavior of a post-installed anchor bar is investigated using a multi-layer analytical model
in this study. The anchor bar is such that used in the concrete jacketing method to strengthen
reinforced concrete bridge piers. The mechanical properties of the infill layer are different from
the surrounding concrete. Therefore the existing pull-out model of deformed bars cannot be
applied directly in this case. By the sensitivity analysis the effect of these parameters is clarified
on the load-displacement curve, shear stress distribution, de-bonded length and the damage of the
surrounding concrete. Then the optimum combination of these parameters is investigated. From
the above analysis, it is confirmed that the elastic modulus of the interface should be large to
reduce the pull-out displacement and the increase of the shear strength of the interface makes the
pull-out load larger