Horizontal Thrust in Vertically Curved Reinforced Concrete Beams

Abstract

This study was conducted to investigate the horizontal thrust of vertically curved reinforced concrete (VCRC) beams. The middle portion of beam is curved like an arch; such beams are said to be vertically curved beams. In this investigation, 15 VCRC beams were cast, of which, 8 beams had a constant rise of 200 mm and varying chord length of curved portion from 490 mm to 1832 mm, and the remaining 7 beams had a constant rise of 300 mm and varying chord length of curved portion from 690 mm to 1844 mm. The vertically curved portions of VCRC beams are in a parabolic shape. Tie bars were used to arrest longitudinal (horizontal) displacement while testing the VCRC beams. VCRC beams were subjected to a gradually increased central concentrated load until collapse occurred. The behavior of the beams was intensely observed from the beginning until collapse occurred. The first crack load, ultimate loads, deflection, and horizontal displacement have been recorded. The force in the tie bars was calculated based on the measured horizontal displacement. The total force in the tie bars is the available horizontal thrust at each end of a VCRC beam. Theoretical horizontal thrust of VCRC beams is calculated based on the force method. These theoretical thrust values and experimental results have been compared. The average value of the ratio of theoretical horizontal thrust to experimental horizontal thrust is found to be very satisfactory.