Understanding Reinforcement Behavior Using Distributed Measurements of Shear Tests

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.

Automated summary

The use of distributed fiber-optic strain sensors allows for a new level of detail in quantifying and understanding reinforced concrete behavior. This investigation found variations in the behavior of longitudinal and transverse reinforcement bars under different shear demands.