A series of tests was conducted to study the stability of longitudinal reinforcing bars in fiber reinforced concrete (FRC) beams under monotonic loading and evaluate whether the ACI Building Code transverse reinforcement spacing limit of 16db can be relaxed in FRC beams. The specimens were simply supported beams subjected to four-point loading, with the middle portion of the beam representing the region under investigation. The test series included FRC specimens with hooked steel fibers in volume fractions of 0.6 and 1.2%. Hoop spacing was set at 24 and 32 longitudinal bar diameters (db), respectively. For comparison, a reinforced concrete (RC) beam with a hoop spacing of 16db was also tested. The specimens were designed so the compression reinforcement would yield in the constant moment region of the beam. Although use of fibers did not prevent bar buckling, test results showed that reinforcement buckling was delayed in the specimens constructed with FRC. Measured deflections when buckling occurred were 1.2-2.3 times greater in the FRC specimens than in the control beam.
Stability of reinforcing bars in steel fiber reinforced concrete flexural members
L. Monfardini;F. Minelli;
2015-01-01
Abstract
A series of tests was conducted to study the stability of longitudinal reinforcing bars in fiber reinforced concrete (FRC) beams under monotonic loading and evaluate whether the ACI Building Code transverse reinforcement spacing limit of 16db can be relaxed in FRC beams. The specimens were simply supported beams subjected to four-point loading, with the middle portion of the beam representing the region under investigation. The test series included FRC specimens with hooked steel fibers in volume fractions of 0.6 and 1.2%. Hoop spacing was set at 24 and 32 longitudinal bar diameters (db), respectively. For comparison, a reinforced concrete (RC) beam with a hoop spacing of 16db was also tested. The specimens were designed so the compression reinforcement would yield in the constant moment region of the beam. Although use of fibers did not prevent bar buckling, test results showed that reinforcement buckling was delayed in the specimens constructed with FRC. Measured deflections when buckling occurred were 1.2-2.3 times greater in the FRC specimens than in the control beam.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
