Title: Understanding Reinforcement Behavior Using Distributed Measurements of Shear Tests
Author(s): Jack J. Poldon, Neil A. Hoult, and Evan C. Bentz
Publication: Structural Journal
Appears on pages(s): 255-266
Keywords: distributed fiber-optic strain sensors; large beams; localized behavior; longitudinal reinforcement; post-yield behavior; shear; stirrups
The use of distributed fiber-optic strain sensors (FOS) has the potential to allow for reinforced concrete behavior to be quantified and understood with a new level of detail. In this investigation, three large reinforced concrete (RC) beams—JP-1, JP-2, and JP-3—with varying percentages of transverse reinforcement, were tested in three-point bending. Distributed FOS were installed on the longitudinal and transverse reinforcement bars, enabling identification and quantification of a number of behavioral mechanisms. These included stirrup demands at all depths and locations in the member, variations in longitudinal bar strain at the
support based on shear demand, and bending of longitudinal bars from stirrup hook anchorage. After longitudinal bar yielding, the development and growth of a plastic hinge was monitored in specimen JP-3 under increasing plastic rotation. Simultaneously, the stirrup strains increased despite being subjected to a near-constant shear force, especially near the critical section for shear.