What should be used to resist diagonal tension in beams?

What should be used to resist diagonal tension in beams?

• A. Stirrups
• B. Longitudinal bars
• C. Bent bars
• D. Welded wire fabric cages

Answer: (A)

Diagonal tension in beams comes from shear forces trying to slide one part of the beam past another along a diagonal crack path. To stop that sliding, transverse reinforcement is placed in the web of the beam. Stirrups are exactly this kind of reinforcement: bars that run across the web and wrap around or cross the main longitudinal bars at regular intervals. By crossing the potential diagonal cracks, they hold the halves of the beam together, bridge the cracks, and convert some of the shear Action into reinforcement strain, which raises the beam’s shear capacity and improves ductility. This is why stirrups are the standard method for resisting diagonal tension in beams. Longitudinal bars are meant to resist bending along the length of the beam, not cross-connecting the web to stop diagonal cracking. Bent bars can provide some shear resistance in certain old or special detailing but aren’t the primary, reliable method for shear reinforcement. Welded wire fabric cages generally don’t offer sufficient shear resistance or anchorage for beam webs, so they aren’t used as the main solution for diagonal tension in beams.

Diagonal tension in beams comes from shear forces trying to slide one part of the beam past another along a diagonal crack path. To stop that sliding, transverse reinforcement is placed in the web of the beam. Stirrups are exactly this kind of reinforcement: bars that run across the web and wrap around or cross the main longitudinal bars at regular intervals. By crossing the potential diagonal cracks, they hold the halves of the beam together, bridge the cracks, and convert some of the shear Action into reinforcement strain, which raises the beam’s shear capacity and improves ductility. This is why stirrups are the standard method for resisting diagonal tension in beams.

Longitudinal bars are meant to resist bending along the length of the beam, not cross-connecting the web to stop diagonal cracking. Bent bars can provide some shear resistance in certain old or special detailing but aren’t the primary, reliable method for shear reinforcement. Welded wire fabric cages generally don’t offer sufficient shear resistance or anchorage for beam webs, so they aren’t used as the main solution for diagonal tension in beams.