Title: Distributed Sensing in Large Reinforced Concrete Shear Test
Author(s): Jack J. Poldon, Neil A. Hoult, and Evan C. Bentz
Publication: Structural Journal
Appears on pages(s): 235-245
Keywords: curvature; digital image correlation; fiber-optic strain sensors; large beams; shear; shear strains; stirrups
A large reinforced concrete (RC) beam designed to fail in shear was experimentally tested and monitored with distributed sensing technologies. Fiber-optic sensors (FOS) were used to monitor the strain along the flexural and shear reinforcement, and digital image correlation (DIC) was used to measure strains and displacements on the concrete surface. Measurements from the distributed sensing technologies were found to be in agreement with conventional sensors when tensile elongation and midspan deflection were analyzed prior to the development of extensive shear cracks. Results showed that cracking on the concrete surface was correlated with peaks in the FOS strain data for both the flexural and shear reinforcement. Combined distributed measurement (CDM) plots presented the full beam response at a given load. A method of monitoring the distributed shear strain was proposed and used to assess the behavior with increasing load and showed that prior to failure, approximately 45% of the beam displacement was due to shear strain. The presented measurement technique using FOS and DIC is shown to enable a more detailed study of shear failures, specifically, in a fashion that enables the quantification of the individual response of reinforcing steel and concrete under loading.