Shear strength of beams reinforced with synthetic macro-fibers and stirrups

Author(s): S. Altoubat, Y. Ardavan, K.A. Rieder
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: 1240 - 1252
Total Pages: 12
Language: English

Abstract: 
This paper presents and discusses experimental results on shear strength and ductility of RC beams. The combined effect of macro synthetic fibers and stirrups on the shear strength and ductility of the RC beams is specifically examined. The experimental program incorporated testing of 16 large beams under center-point monotonic loading. The beams were tested with a shear span to depth ratio of 2.3 and 3.5. The beam cross-section was 390 × 230 mm, and the amount and spacing of the stirrups were chosen to comply with the ACI-318-05 requirements for minimum shear reinforcement. Synthetic macro fibers were added at a volume fraction of 0.5%. The results showed that the addition of macro synthetic fibers significantly improved the shear strength and ductility of the RC beams and modified its cracking and failure behavior in a similar pattern as that with conventional minimum ACI shear reinforcement. The macro synthetic fibers improved the shear strength of the slender and short RC by 14% and 18%. Similarly, the addition of minimum ACI 318 stirrups increased the shear strength of the slender and short beams by 19%.The results also showed that the use of both stirrups and macro synthetic fibers at volume fraction of 0.50% improved shear strength of slender and short beams by 69% and 42%, respectively. These improvements showed that the combined use of the synthetic macro fibers and minimum stirrups has significant synergistic effects on shear strength. The results suggest that the synergy depends not only on the type of fibers and extent of reinforcement but also on the slenderness of the beam.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00