Abstract
Eight ultra-high-strength concrete (UHSC) square columns were constructed and tested to investigate the effects of yield strength of transverse (fyh ≈ 550 and 800 MPa [79.8 and 116.0 ksi]) and longitudinal reinforcement (fyh ≈ 480 and 640 MPa [69.6 and 92.8 ksi]) on axial load response. The UHSC had compressive strengths varying from 185 to 200 MPa (26.8 to 29.0 ksi). The effects of using high-strength transverse reinforcement with two different configurations and amounts were evaluated. For a constant amount of confinement reinforcement, high-strength transverse reinforcement improves the performance of well-confined UHSC columns in terms of strength, post-peak deformability, and toughness, provided that the hoops are detailed with proper end anchorage (135-degree seismic hooks). The use of high-strength transverse reinforcement was also effective in reducing steel congestion for UHSC columns. The effects of using high-strength longitudinal reinforcement in UHSC columns were also studied. It was determined that the combination of high-strength longitudinal reinforcement and UHSC results in yielding of this reinforcement. However, for typical longitudinal reinforcement ratios, the benefit of using high-strength longitudinal steel is limited due to the relatively small contribution of this reinforcement to the strength of UHSC columns and the early cover spalling of UHSC.
Original language | English |
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Pages (from-to) | 325-336 |
Number of pages | 12 |
Journal | ACI Structural Journal |
Volume | 113 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2016 Mar 1 |
Keywords
- Axial load
- Columns
- Confinement
- High-strength longitudinal reinforcement
- High-strength transverse reinforcement
- Ultra-high-strength concrete
ASJC Scopus subject areas
- Building and Construction
- Civil and Structural Engineering