Title:
Effectiveness of Web Reinforcement around Openings in Continuous Concrete Deep Beams
Author(s):
Keun-Hyeok Yang and Ashraf F. Ashour
Publication:
Structural Journal
Volume:
105
Issue:
4
Appears on pages(s):
414-424
Keywords:
beam; load capacity; shear; web reinforcement
DOI:
10.14359/19855
Date:
7/1/2008
Abstract:
Twenty-two reinforced concrete continuous deep beams with openings and two companion solid deep beams were tested to failure. The main variables investigated were the configuration of web reinforcement around openings, location of openings, and shear span-to-overall depth ratio. Web openings were located in either exterior or interior shear spans and the shear span-to-overall depth ratio was selected to be 0.6 and 1.0. The development of diagonal crack width and load capacity of beams having openings within exterior shear spans were insensitive to the configuration of web reinforcement. For beams having openings within interior shear spans, however, inclined web reinforcement was the most effective type for controlling diagonal crack width and increasing load capacity. It has also been observed that higher load and shear capacities were exhibited by beams with web reinforcement above and below openings than those with web reinforcement only above openings. The shear capacity of continuous beams having a shear span-to-overall depth ratio of 0.6 is underestimated using Kong et al.’s formula, whereas the predicted shear capacity of beams having a shear span-to-overall depth ratio of 1.0 is in good agreement with test results. The mechanism analysis based on the upper bound theorem also underestimates the load capacity of continuous deep beams having openings within exterior shear spans but shows better agreement with that of continuous deep beams having openings within interior shear spans.