Details
| Original language | English |
|---|---|
| Pages (from-to) | 437-452 |
| Number of pages | 16 |
| Journal | Construction and Building Materials |
| Volume | 211 |
| Publication status | Published - 30 Jun 2019 |
| Externally published | Yes |
Abstract
Building, bridges and other civil structures usually require at some point in their service life a rehabilitation for reasons such as aging, increased load limits or fatigue. Application of iron-based shape memory alloy (Fe-SMA) members for prestress-strengthening of such structures has been recently introduced. Since civil structures are potentially subject to the fire hazard, the high-temperature mechanical behavior of retrofit materials is of great importance. Therefore, this work aims at providing the first systematic study on the structural fire behavior of Fe-SMA prestress-strengthened structural members. For this purpose, a series of transient total deformation tests was conducted on prestressed Fe-SMA strips of two different thicknesses of 1.5 and 0.5 mm. The transient lab-tests were performed to determine the creep-onset and failure temperatures of the Fe-SMA strips at different service load levels of 0, 80 and 240 N/mm 2 and heating rates of 5, 15 and 50 °C/min. The results showed that (1) a creep-onset temperature greater than 500 °C was observed at all different service load levels and heating rates; and (2) both the creep-onset and failure temperatures decreased with increasing service load levels. Finally, a simple engineering model was developed to estimate the fire-induced prestress loss in Fe-SMA members of retrofitted civil structures.
Keywords
- Elevated and high temperatures, Fe-Mn-Si SMA, Fire exposure, Iron-based shape memory alloy (Fe-SMA), Mechanical properties, Prestressed strengthening, Structural fire engineering
ASJC Scopus subject areas
- Engineering(all)
- Civil and Structural Engineering
- Engineering(all)
- Building and Construction
- Materials Science(all)
- General Materials Science
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In: Construction and Building Materials, Vol. 211, 30.06.2019, p. 437-452.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Elevated temperature behavior of an iron-based shape memory alloy used for prestressed strengthening of civil structures
AU - Ghafoori, Elyas
AU - Neuenschwander, Martin
AU - Shahverdi, Moslem
AU - Czaderski, Christoph
AU - Fontana, Mario
N1 - Funding Information: The authors would like to acknowledge the help from Ms. Veronika Zemp in conducting the laboratory tests. Thanks also go to re-fer AG Company, Switzerland, for providing the Fe-SMA material for the experimental series. This research was partially made with Government support under and awarded by the Swiss National Science Foundation (SNSF), Switzerland, SNSF Early PostDoc Mobility Fellowship (Project Number P2EZP2_175298) provided to Dr. Neuenschwander. Publisher Copyright: © 2019 Elsevier Ltd
PY - 2019/6/30
Y1 - 2019/6/30
N2 - Building, bridges and other civil structures usually require at some point in their service life a rehabilitation for reasons such as aging, increased load limits or fatigue. Application of iron-based shape memory alloy (Fe-SMA) members for prestress-strengthening of such structures has been recently introduced. Since civil structures are potentially subject to the fire hazard, the high-temperature mechanical behavior of retrofit materials is of great importance. Therefore, this work aims at providing the first systematic study on the structural fire behavior of Fe-SMA prestress-strengthened structural members. For this purpose, a series of transient total deformation tests was conducted on prestressed Fe-SMA strips of two different thicknesses of 1.5 and 0.5 mm. The transient lab-tests were performed to determine the creep-onset and failure temperatures of the Fe-SMA strips at different service load levels of 0, 80 and 240 N/mm 2 and heating rates of 5, 15 and 50 °C/min. The results showed that (1) a creep-onset temperature greater than 500 °C was observed at all different service load levels and heating rates; and (2) both the creep-onset and failure temperatures decreased with increasing service load levels. Finally, a simple engineering model was developed to estimate the fire-induced prestress loss in Fe-SMA members of retrofitted civil structures.
AB - Building, bridges and other civil structures usually require at some point in their service life a rehabilitation for reasons such as aging, increased load limits or fatigue. Application of iron-based shape memory alloy (Fe-SMA) members for prestress-strengthening of such structures has been recently introduced. Since civil structures are potentially subject to the fire hazard, the high-temperature mechanical behavior of retrofit materials is of great importance. Therefore, this work aims at providing the first systematic study on the structural fire behavior of Fe-SMA prestress-strengthened structural members. For this purpose, a series of transient total deformation tests was conducted on prestressed Fe-SMA strips of two different thicknesses of 1.5 and 0.5 mm. The transient lab-tests were performed to determine the creep-onset and failure temperatures of the Fe-SMA strips at different service load levels of 0, 80 and 240 N/mm 2 and heating rates of 5, 15 and 50 °C/min. The results showed that (1) a creep-onset temperature greater than 500 °C was observed at all different service load levels and heating rates; and (2) both the creep-onset and failure temperatures decreased with increasing service load levels. Finally, a simple engineering model was developed to estimate the fire-induced prestress loss in Fe-SMA members of retrofitted civil structures.
KW - Elevated and high temperatures
KW - Fe-Mn-Si SMA
KW - Fire exposure
KW - Iron-based shape memory alloy (Fe-SMA)
KW - Mechanical properties
KW - Prestressed strengthening
KW - Structural fire engineering
UR - http://www.scopus.com/inward/record.url?scp=85063349307&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2019.03.098
DO - 10.1016/j.conbuildmat.2019.03.098
M3 - Article
AN - SCOPUS:85063349307
VL - 211
SP - 437
EP - 452
JO - Construction and Building Materials
JF - Construction and Building Materials
SN - 0950-0618
ER -