Effect of hybrid fibers on the flexural performance of high‐strength recycled aggregate concrete beams

• Published in: Structural concrete : journal of the FIB Vol. 25; no. 1; pp. 403 - 422
• Main Authors: Niu, Haicheng, Li, Bohan, Gao, Jinlong, Xie, Shu
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH & Co. KGaA 01.02.2024; Wiley Subscription Services, Inc
• Subjects: Concrete aggregates; Deformation effects; fiber reinforced concrete beams; flexural performance; Flexural strength; Formability; high‐strength recycled concrete; hybrid fibers; Polyvinyl alcohol; polyvinyl alcohol fiber; Recycled materials; steel fiber; Steel fibers
• ISSN: 1464-4177; 1751-7648
• DOI: 10.1002/suco.202200990

Fibers are mixed within reinforced high‐strength recycled aggregate concrete (RHRAC) beams to improve their flexural performance. This study experimentally and analytically investigates the effect of using RAC combined with polyvinyl alcohol fiber (PVAF) and steel fiber (SF) on the flexural performance of RHRAC beams. A total of 11 RHRAC beams (150 × 300 × 2600 mm3) are manufactured and subject to four‐point flexural testing. The parameters of the concrete are investigated, including the volume content of the PVAF and SF. The experimental results show that SF increases the flexural strength of RHRAC beams more than PVAF does. Conversely, the effect of PVAF on deformability is more significant than that of SF. In addition, the positive influences of hybrid fiber (PVAF and SF) on the crack load, flexural capacity, and deformation capacity are superior to those of single‐mixed PVAF or SF. Three different specifications are used to calculate the flexural capacity of the test beams, among which, JGJ/T465‐2019 is the most reliable.