Pull-out behavior evaluation of torque-controlled expansion anchors under various installation conditions of concrete

Abstract

Torque-controlled expansion anchors are widely used as anchoring elements in heavy nonstruc-tural elements. Although the installed torque is not considered a design parameter for determi-nation of anchor strength, it can affect the contact condition between the concrete and anchor as well as the failure mode under tensile load. This study performed pull-out experiments (total 85 specimens) for torque-controlled expansion anchors to evaluate the pull-out behavior under various installation conditions. Experimental results indicated that obtained inflection load and maximum displacement were affected by the installation torque. Concrete splitting failure was affected by pull-out behavior on concrete below critical edge distance. While maximum pull-out loads of M12 and M16 anchor was similar under the same embedment depth, pull-out behavior of the both types of anchors provide different characteristic. Accordingly, these results were analyzed to investigate the influence on anchor strength.