EXPERIMENTAL STUDY ON HALF-PRECAST REINFORCED CONCRETE BEAMS WITH TRUSS-SHAPED REINFORCING BARS

摘要

Arrangement of main and shear reinforcing barsin the shape of truss makes a reinforcing bar frame with highflexural rigidity for reinforced concrete (RC) beams.he construction load during concrete placement is sustained bythis frame, it would be possible to enhancethe workability to great extent by saving site work and reducingthe number of supports underneath.The purpose of this study is to clarify structural performance ofthe RC beam with truss-shaped reinforcement in the case ofusing half-precast concrete panel on behalf of the bottom form panel.In this paper, results of weight loading test of the truss-shapedreinforcing bar frame and concrete placing test of the RC beamwith truss-shaped reinforcement are presented. And also flexuraltest results of the hardened RC beams unber both monotonousand cyclic loading are presented.The following conclusions are obtained.(1)The truss-shaped reinforcing bar frame with precast concreteis able to sustain the construction load during concreteplacement without setting supports undemeath.(2)Influence of the differrence in both the surface condition andthe type of precast concrete on overall flexural performance ofthe RC beams is small, though cracks develop alongconstruction joint of the beam.(3)The RC beam with truss-shaped reinforcement shows thesame flexural performance as the RC beam with conventional reinforcement.