Details
| Original language | English |
|---|---|
| Article number | 119286 |
| Number of pages | 15 |
| Journal | Engineering structures |
| Volume | 323 |
| Early online date | 15 Nov 2024 |
| Publication status | E-pub ahead of print - 15 Nov 2024 |
Abstract
This study presents an innovative application of smart metals for the prestressed strengthening of roadway bridges. The target structure is a steel–concrete composite bridge, in which poor construction practices cause nonlinear creep, excessive deflection, and crack growth. However, the high flood water level of the creek below the bridge limits the application of conventional strengthening solutions. Therefore, an innovative strengthening method using iron-based shape memory alloy (Fe-SMA) bars for the post-tensioning of bridge members was designed and employed. The study framework encompassed the design, laboratory examination, installation, and monitoring of Fe-SMA reinforcements. A finite-element simulation was used to estimate the effect of applied prestressing on the stress distribution of the structure. High-cycle fatigue tests of Fe-SMA bars with different types of connections at room temperature and –20 °C, were conducted to select the most reliable connections. A total of approximately 825 m of Fe-SMA bars with a diameter of 18 mm, comprising 68 Fe-SMA bars, were installed and activated. A wireless sensor monitoring system consisting of strain gauges, potentiometers, linear-variable differential transformer sensors, and thermocouples was utilized to measure the changes in strain and stress of the designed system under field conditions. The results revealed a prestress loss of 8.5 % owing to relaxation after six months, which match well to the values obtained by the laboratory tests. A second static loading test was conducted approximately six months after strengthening, and the results indicated a 9 % reduction in mid-span deflection and a remarkable 106 % reduction in average stresses in the lower flange at the mid-span of the beams. The results of monitoring the bridge for a duration longer than 6 months highlighted a significant decrease in the mid-span deflection and indicated the potential of Fe-SMAs for the lifetime extension of bridges.
Keywords
- Bridge, Iron-based shape memory alloy, Lifetime extension, Prestressed strengthening, Recovery stress, Strengthening, Structural health monitoring
ASJC Scopus subject areas
- Engineering(all)
- Civil and Structural Engineering
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In: Engineering structures, Vol. 323, 119286, 15.01.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Strengthening, lifetime extension, and monitoring of a deficient steel–concrete composite roadway bridge using iron-based shape memory alloys
AU - Vůjtěch, Jakub
AU - Ryjáček, Pavel
AU - Moshayedi, Hessamoddin
AU - Matos, Jose Campos
AU - Ghafoori, Elyas
N1 - Publisher Copyright: © 2024 The Authors
PY - 2024/11/15
Y1 - 2024/11/15
N2 - This study presents an innovative application of smart metals for the prestressed strengthening of roadway bridges. The target structure is a steel–concrete composite bridge, in which poor construction practices cause nonlinear creep, excessive deflection, and crack growth. However, the high flood water level of the creek below the bridge limits the application of conventional strengthening solutions. Therefore, an innovative strengthening method using iron-based shape memory alloy (Fe-SMA) bars for the post-tensioning of bridge members was designed and employed. The study framework encompassed the design, laboratory examination, installation, and monitoring of Fe-SMA reinforcements. A finite-element simulation was used to estimate the effect of applied prestressing on the stress distribution of the structure. High-cycle fatigue tests of Fe-SMA bars with different types of connections at room temperature and –20 °C, were conducted to select the most reliable connections. A total of approximately 825 m of Fe-SMA bars with a diameter of 18 mm, comprising 68 Fe-SMA bars, were installed and activated. A wireless sensor monitoring system consisting of strain gauges, potentiometers, linear-variable differential transformer sensors, and thermocouples was utilized to measure the changes in strain and stress of the designed system under field conditions. The results revealed a prestress loss of 8.5 % owing to relaxation after six months, which match well to the values obtained by the laboratory tests. A second static loading test was conducted approximately six months after strengthening, and the results indicated a 9 % reduction in mid-span deflection and a remarkable 106 % reduction in average stresses in the lower flange at the mid-span of the beams. The results of monitoring the bridge for a duration longer than 6 months highlighted a significant decrease in the mid-span deflection and indicated the potential of Fe-SMAs for the lifetime extension of bridges.
AB - This study presents an innovative application of smart metals for the prestressed strengthening of roadway bridges. The target structure is a steel–concrete composite bridge, in which poor construction practices cause nonlinear creep, excessive deflection, and crack growth. However, the high flood water level of the creek below the bridge limits the application of conventional strengthening solutions. Therefore, an innovative strengthening method using iron-based shape memory alloy (Fe-SMA) bars for the post-tensioning of bridge members was designed and employed. The study framework encompassed the design, laboratory examination, installation, and monitoring of Fe-SMA reinforcements. A finite-element simulation was used to estimate the effect of applied prestressing on the stress distribution of the structure. High-cycle fatigue tests of Fe-SMA bars with different types of connections at room temperature and –20 °C, were conducted to select the most reliable connections. A total of approximately 825 m of Fe-SMA bars with a diameter of 18 mm, comprising 68 Fe-SMA bars, were installed and activated. A wireless sensor monitoring system consisting of strain gauges, potentiometers, linear-variable differential transformer sensors, and thermocouples was utilized to measure the changes in strain and stress of the designed system under field conditions. The results revealed a prestress loss of 8.5 % owing to relaxation after six months, which match well to the values obtained by the laboratory tests. A second static loading test was conducted approximately six months after strengthening, and the results indicated a 9 % reduction in mid-span deflection and a remarkable 106 % reduction in average stresses in the lower flange at the mid-span of the beams. The results of monitoring the bridge for a duration longer than 6 months highlighted a significant decrease in the mid-span deflection and indicated the potential of Fe-SMAs for the lifetime extension of bridges.
KW - Bridge
KW - Iron-based shape memory alloy
KW - Lifetime extension
KW - Prestressed strengthening
KW - Recovery stress
KW - Strengthening
KW - Structural health monitoring
UR - http://www.scopus.com/inward/record.url?scp=85209100009&partnerID=8YFLogxK
U2 - 10.1016/j.engstruct.2024.119286
DO - 10.1016/j.engstruct.2024.119286
M3 - Article
AN - SCOPUS:85209100009
VL - 323
JO - Engineering structures
JF - Engineering structures
SN - 0141-0296
M1 - 119286
ER -