Experimental and analytical investigation of concrete failure modes in strand lifting loops under inclined loads

This study investigates experiments and analyses related to the use of strand lifting loops for handling precast concrete members. To this end, a total of 24 specimens were prepared, with variables including edge distance, lifting angle, and embedment depth. A finite element analysis of the experimental conditions was conducted to validate the experimental method. In the experiments, each specimen was independently manufactured and tested under individually applied loads. The experimental results were analyzed in terms of the failure modes and strengths of the specimens with respect to the key variables. The results revealed that the failure modes of the specimens could be categorized into concrete splitting failure, concrete breakout failure, and strand tensile rupture, all of which were closely related to the influencing factor, embedment depth divided by edge distance. Based on the experimental results, modification factors for the design of strand lifting loops are proposed. The findings indicate that the predicted strengths, obtained by applying these modification factors to the anchor design equations from ACI 318, effectively reflect the effects of the key variables.