Experimental Evaluation of Influence of Member Thickness, Anchor-Head Size, and Orthogonal Surface Reinforcement on the Tensile Capacity of Headed Anchors in Uncracked Concrete

Abstract

Cast-in-place headed anchors with different head sizes embedded in plain and reinforced concrete members of various thicknesses were subjected to pullout tests. The influence of member thickness, anchor-head size, and orthogonal surface reinforcement on the tensile capacity and performance of anchor bolts was evaluated. The member thickness varied from 1.5 to 3.0 times the anchor embedment depth, and headed anchors with small, medium, and large heads were tested. The experimental results of the study showed that increasing member thickness and/or use of orthogonal surface reinforcement lead to increased anchorage capacity and ductility, whereas the anchorage stiffness decreases slightly. In contrast to anchorage ductility, tensile breakout resistance and anchorage stiffness increased significantly with increasing size of the anchor head. The experimental results corresponded closely to the results of a previous numerical study that suggested a modified model incorporating several modification factors for improving the predictive capability of the concrete capacity (CC) method. In the present study, these factors yielded improved prediction of the tensile breakout capacity of the tested headed anchors.