Title:
Understanding Shear-Resistance Mechanisms in Concrete Beams Monitored with Distributed Sensors
Author(s):
Jack J. Poldon, Neil A. Hoult, and Evan C. Bentz
Publication:
Structural Journal
Volume:
119
Issue:
6
Appears on pages(s):
329-340
Keywords:
aggregate interlock; digital image correlation (DIC); distributed fiber-optic strain sensors; large beams; shear; stirrups
DOI:
10.14359/51737148
Date:
11/1/2022
Abstract:
The shear-carrying mechanism in reinforced concrete (RC) has
long been uncertain, partly because previously available sensors were insufficient for capturing local behavior. In this study, three large RC beams with stirrups were instrumented with distributed fiber-optic sensors (DFOS) to measure the strain along the full length of the reinforcing bars, while digital image correlation (DIC) was used to measure distributed crack movement to calculate the forces that they transfer. The DFOS measurements along the stirrups showed that the total stirrup force along a shear crack was insufficient to resist the total applied shear. Free-body diagrams (FBD) were constructed along diagonal cracks using the sensor measurements and constitutive relations to investigate if the resulting summation of forces would be in equilibrium, and the results suggest that the main elements of shear resistance have been, at least approximately, identified for the first time with the aid
of distributed sensing.