Title: Behavior and Strength of Glass Fiber-Reinforced Polymer- Reinforced Concrete Deep Beams with Web Openings
Author(s): Jacob Frappier, Khaled Mohamed, Ahmed Sabry Farghaly, and Brahim Benmokrane
Publication: Structural Journal
Appears on pages(s): 275-286
Keywords: deep beams; glass fiber-reinforced polymer bars; openings; shear strength; steel; strain; strut-and-tie model
The current study investigated the behavior of reinforced concrete deep beams with web openings. Seven deep beams were tested: five had web openings—of which three were reinforced with glass fiber-reinforced polymer (GFRP) bars and two reference specimens were reinforced with steel bars—and two solid deep beams, one with GFRP bars and one with steel bars as reference. The beams were 1200 x 300 mm in cross section and 5000 mm in span. The shear span-depth ratio (a/d) was 1.13. The openings in the beam webs were 304 mm high and 340 mm wide. Different GFRP and steel reinforcement configurations were provided around the web opening. The results were analyzed in terms of cracking pattern, mode of failure, load-deflection behavior, opening effect, and efficiency of the reinforcement configuration. The GFRP- and steel-reinforced solid deep beams exhibited similar resistance, while the GFRP-reinforced deep beams with openings had slightly lower capacity than the steel-reinforced ones. Strut-and-tie models (STMs) available in ACI and CSA design codes and the literature were assessed. The accuracy of each model was confirmed, revealing the applicability of the STMs for complex truss models as in deep beams with web openings.