Details
| Original language | English |
|---|---|
| Article number | 108289 |
| Number of pages | 18 |
| Journal | Structures |
| Volume | 72 |
| Early online date | 26 Jan 2025 |
| Publication status | Published - Feb 2025 |
Abstract
Iron-based shape memory alloys (Fe-SMAs) have gradually become a research hotspot in the field of structural strengthening due to their convenient application of prestress. However, unlike traditional prestressing methods, it is challenging to intuitively determine the effective prestress of Fe-SMAs using instrumentation. This study conducted bending tests on eight concrete T-beams near-surface mounted (NSM) with Fe-SMA bars to elucidate the effects of Fe-SMA reinforcement ratios and activation temperatures on flexural performance. The effect of preload on the recovery stress was investigated, leading to the proposal of a formula for calculating effective prestress. The results indicate that increasing the Fe-SMA reinforcement ratio positively influences load at service limit state, ultimate load, and post-cracking stiffness. With an increase in the activation temperature or reinforcement ratio, the residual displacement was reduced by at least 50 %. The effective prestress of Fe-SMAs is influenced by both the preload of Fe-SMA and the crack closure of specimens. As the preload increases, the recovery deformation capacity of the Fe-SMAs decreases. The theoretical values of anti-arch calculated using the proposed model match closely with the measured values. Fe-SMA NSM strengthening could be applied rapidly and demonstrated favourable strengthening effects.
Keywords
- Effective prestress, Flexural behaviour, Iron-based shape memory alloy (Fe-SMA) bar, Near-surface mounted (NSM) strengthening
ASJC Scopus subject areas
- Engineering(all)
- Civil and Structural Engineering
- Engineering(all)
- Architecture
- Engineering(all)
- Building and Construction
- Engineering(all)
- Safety, Risk, Reliability and Quality
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In: Structures, Vol. 72, 108289, 02.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Investigation on effective prestress in Fe-SMA bars and flexural behaviour of damaged T-shaped RC beams strengthened by NSM method
AU - Sun, Yu
AU - Dong, Zhiqiang
AU - Zhu, Hong
AU - Wu, Gang
AU - Sun, Zeyang
AU - Sun, Xinliang
AU - Ghafoori, Elyas
N1 - Publisher Copyright: © 2025 Institution of Structural Engineers
PY - 2025/2
Y1 - 2025/2
N2 - Iron-based shape memory alloys (Fe-SMAs) have gradually become a research hotspot in the field of structural strengthening due to their convenient application of prestress. However, unlike traditional prestressing methods, it is challenging to intuitively determine the effective prestress of Fe-SMAs using instrumentation. This study conducted bending tests on eight concrete T-beams near-surface mounted (NSM) with Fe-SMA bars to elucidate the effects of Fe-SMA reinforcement ratios and activation temperatures on flexural performance. The effect of preload on the recovery stress was investigated, leading to the proposal of a formula for calculating effective prestress. The results indicate that increasing the Fe-SMA reinforcement ratio positively influences load at service limit state, ultimate load, and post-cracking stiffness. With an increase in the activation temperature or reinforcement ratio, the residual displacement was reduced by at least 50 %. The effective prestress of Fe-SMAs is influenced by both the preload of Fe-SMA and the crack closure of specimens. As the preload increases, the recovery deformation capacity of the Fe-SMAs decreases. The theoretical values of anti-arch calculated using the proposed model match closely with the measured values. Fe-SMA NSM strengthening could be applied rapidly and demonstrated favourable strengthening effects.
AB - Iron-based shape memory alloys (Fe-SMAs) have gradually become a research hotspot in the field of structural strengthening due to their convenient application of prestress. However, unlike traditional prestressing methods, it is challenging to intuitively determine the effective prestress of Fe-SMAs using instrumentation. This study conducted bending tests on eight concrete T-beams near-surface mounted (NSM) with Fe-SMA bars to elucidate the effects of Fe-SMA reinforcement ratios and activation temperatures on flexural performance. The effect of preload on the recovery stress was investigated, leading to the proposal of a formula for calculating effective prestress. The results indicate that increasing the Fe-SMA reinforcement ratio positively influences load at service limit state, ultimate load, and post-cracking stiffness. With an increase in the activation temperature or reinforcement ratio, the residual displacement was reduced by at least 50 %. The effective prestress of Fe-SMAs is influenced by both the preload of Fe-SMA and the crack closure of specimens. As the preload increases, the recovery deformation capacity of the Fe-SMAs decreases. The theoretical values of anti-arch calculated using the proposed model match closely with the measured values. Fe-SMA NSM strengthening could be applied rapidly and demonstrated favourable strengthening effects.
KW - Effective prestress
KW - Flexural behaviour
KW - Iron-based shape memory alloy (Fe-SMA) bar
KW - Near-surface mounted (NSM) strengthening
UR - http://www.scopus.com/inward/record.url?scp=85216018479&partnerID=8YFLogxK
U2 - 10.1016/j.istruc.2025.108289
DO - 10.1016/j.istruc.2025.108289
M3 - Article
AN - SCOPUS:85216018479
VL - 72
JO - Structures
JF - Structures
SN - 2352-0124
M1 - 108289
ER -