Title: Ductility of Ultra-High Performance Concrete Beams Reinforced with Ordinary, High-Strength and Stainless Steel Bars

Author(s): Yang Li and Hassan Aoude

Publication: Symposium Paper

Volume: 351

Issue:

Appears on pages(s): 129-150

Keywords: bar fracture; beams; ductility; high-strength steel; stainless steel; UHPC

DOI: 10.14359/51734679

Date: 4/1/2022

Abstract:
Ultra-high performance concrete (UHPC) is a novel material which shows impressive properties including high strength, increased toughness and excellent durability. One of the potential applications of UHPC is in heavily-loaded beams and bridge girders where their use can allow for more efficient design sections and increased durability. On the other hand, the high bond capacity of UHPC can eventually lead to brittle bar fracture failures in flexural members, especially when combined with low or moderate amounts of ordinary steel reinforcement (ρ ≤ 1%). This paper examines the influence of reinforcement grade on the flexural behaviour of UHPC beams. As part of the study, a series of UHPC beams built with either Grade 400 MPa ordinary steel reinforcement, Grade 690 MPa high-strength reinforcement or Grade 520 MPa stainless steel reinforcement are tested under four-point bending. The main parameters investigated include the influence of UHPC, steel type and tension steel ratio. Overall the results show that the ductility of the UHPC beams is influenced by both the tension steel ratio and steel grade/type. The results also show the benefits of combining UHPC with higher grade or higher ductility steel reinforcement.