Flexural behavior of hollow reinforced concrete haunched (RCH) beams

Abstract

Hollow reinforced concrete hunched (RCH) beams are getting popularity due to low cost and low weight as compared with the solid RCH beams. Hollow RCH beams present a dramatic decrease in weight, without sacrificing strength and durability. The result is a product capable of spanning long lengths, all while: Reducing the need for excessive steel and concrete. Hollow bunched beams are used for monorail bridge girders. This research paper presents results of any experimental investigation conducted on hollow RCH beams representative of construction details of girders of monorail sky train in Bangkok, Thailand. In the first step, a large-scale hollow RCH beam (HB-01) was constructed at 1/5th scale (total length = 6.6 meter) and tested. Whereas in the second step, size, and configuration of hollow opening in hollow RCH beams were modified to study their effect on ultimate load carrying capacity and mid-span deflection of hollow RCH beams. For this purposes, two additional beams, i.e., HB-02 and HB-03 were constructed, tested and their results were compared with the control beam, i.e., HB-01. In case of hollow RCH beam HB-02, the size of hollow opening was increased by 68% and configuration of hollow opening along the length of the beam was kept identical to the control beam. Whereas in case of hollow RCH beam HB-03, the size of hollow opening was kept identical to control beam and length of hollow opening was extended to the ends of hollow RCH beam. All beams were tested under four-point bending scheme. The experimental results indicate that ultimate behaviour of hollow RCH beams is pure flexure and controlled by yielding of both tension and compression steel bars. Further, it is found that considered size and configuration of the hollow opening had a negligible effect on the load carrying capacity and mid-span deflection of hollow RCH beams. © School of Engineering, Taylor’s University.