Civil Engineering Reference
In-Depth Information
Figure 8.11
Loading positions and LVDT rosettes in beams B1-B5 (all dimensions are in mm)
vertical stirrups inside the beams to monitor the steel strains during the load test. The locations
of strain gages on the stirrups were selected so that they intersected the predicted shear failure
planes of the beams. It was found that stirrup strains reached yielding and beyond at failure,
with many stirrups far into the strain hardening range. In short, the stirrups in all five beams,
B1-B5, can be assumed to yield at shear failure.
8.3.2.2 Test Results
The load-deflection curves of the five beams B1-B5 are shown in Figure 8.12. Curves 1-6
represent the north and south ends of the group of three beams B1-B3, which have
a/d
1.61.
All three experimental curves follow the theoretical curve 11 based on flexural analysis until
the beams failed in web-shear mode. Similarly, curves 7-10 represent the north and south ends
of the group of two beams B4-B5, which have
a/d
=
=
4.29. All the experimental curves of
these two beams followed the theoretical curve 12 based on flexural analysis until the beams
failed in flexural-shear mode.
Shear-span-to-depth ratio (
a/d
)
Figure 8.12 clearly shows that the beams designed for web-shear failure (B1, B2 and B3)
had much higher shear capacities compared with the beams designed to fail in flexural-shear
