EXPERIMENTAL STUDY ON SHEAR BEHAVIOR OF RC BEAMS USING U-SHAPED UFC PERMANENT FORMWORK WITH SHEAR KEYS AND BOLTS

Abstract

UFC is one of the cementitious materials which have outstanding properties such as more than 200 MPa compressive strength, high ductility and durability. The permanent formwork for RC structures is one of the promising applications of UFC. This research is aimed to investigate the shear behavior of RC beams using a U-shaped UFC permanent formwork. Eight RC beams using a U-shaped UFC permanent formwork were tested by four-point bending test. The experimental parameters were the presence of shear keys at the internal surface of a UFC U-shaped permanent formwork, presence of screws and bolts, thickness of formwork, shear span to effective depth ratio and presence of stirrups. The experimental results indicated that a U-shaped UFC permanent formwork enhanced the shear capacity of RC beams more than twice compared to normal RC beams. In addition, the shear resistance mechanisms were investigated. By using a UFC formwork with shear keys and screwed bolts, the UFC formwork intercepted widening of diagonal cracks inside a RC part. Finally, the shear carried by a UFC permanent formwork was investigated. The proposed calculation method can provide a good agreement with the experimental values.