STRENGTH EVALUATION OF LOOP JOINT OF PRECAST BEAM FOR PORT PIER

Abstract

 Recently, the introduction of precast concrete to the port pier is progressing in order to improve productivity. When the precast method is applied to the upper concrete of port pier, it is common to weld the main reinforcement and steel pipe piles by field welding in order to transmit the moment. The authors propose a new connection structure of pile top using loop joint which eliminates field welding and minimizes cast-in-place concrete. In this study, tensile tests for small specimens and reversed cyclic bending tests for beams were performed for practical application of this method and establishment of design method. The present result suggested that the strength of the loop can be evaluated by considering the decrease in strength by 20% in the existing Leonhardt’s equation. Furthermore, it suggested that beams joined by separate loop joints have the same strength as continuous double reinforcement without loops even under the conditions where positive and negative bending are repeatedly applied.