TY - JOUR

T1 - Iron-Based shape memory alloy for strengthening of 113-Year bridge

AU - Vůjtěch, Jakub

AU - Ryjáček, Pavel

AU - Campos Matos, Jose

AU - Ghafoori, Elyas

N1 - Funding Information: The authors are grateful to the Ministry of Culture of the Czech Republic for funding the research work within the framework of the Program of Applied Research and Development of the National and Cultural Identity (NAKI-II) project: Methods for achieving sustainability of industrial heritage steel bridges, ID: DG18P02OVV033. The authors also thank the re-fer AG Company for providing materials used for this study. Publisher Copyright: © 2021 The Authors

PY - 2021/12/1

Y1 - 2021/12/1

N2 - This study focuses on the large-scale application of a Fe-Mn-Si shape memory alloy (Fe-SMA) for strengthening a historic roadway bridge in Petrov nad Desnou (113-years), Czech Republic. To the best of the authors’ knowledge, this is the first application of an iron-based SMA (Fe-SMA) for prestressed strengthening of a bridge. In this study, the shape memory effect (SME) of the Fe-SMA was used for the prestressed strengthening of bridge girders. A mechanical anchorage system was developed to apply multiple Fe-SMA strips to the steel girders of the bridge subjected to daily passengers and heavy trucks. The SME of the Fe-SMA was activated by heating to approximately 260 °C using ceramic heating pads. The test results showed that the recovery stress of the Fe-SMA strips resulted in a compressive stress of approximately –33 MPa in the lower flange of the bridge girder. This compressive stress significantly increased the yield and fatigue capacity of the strengthened girder. Before and after the strengthening, the bridge was loaded with a 45-ton crane to assess the efficiency and performance of the system. Laboratory experiments were performed to optimize the mechanical anchors and examine the feasibility of the proposed strengthening method prior to application to the bridge. Finally, long-term monitoring of the prestressed Fe-SMA plates after installation on the bridge was conducted. The results showed that the main loss of the prestressing force caused by relaxation occurred within the first 30 days after activation and was approximately 20% of the original prestress.

AB - This study focuses on the large-scale application of a Fe-Mn-Si shape memory alloy (Fe-SMA) for strengthening a historic roadway bridge in Petrov nad Desnou (113-years), Czech Republic. To the best of the authors’ knowledge, this is the first application of an iron-based SMA (Fe-SMA) for prestressed strengthening of a bridge. In this study, the shape memory effect (SME) of the Fe-SMA was used for the prestressed strengthening of bridge girders. A mechanical anchorage system was developed to apply multiple Fe-SMA strips to the steel girders of the bridge subjected to daily passengers and heavy trucks. The SME of the Fe-SMA was activated by heating to approximately 260 °C using ceramic heating pads. The test results showed that the recovery stress of the Fe-SMA strips resulted in a compressive stress of approximately –33 MPa in the lower flange of the bridge girder. This compressive stress significantly increased the yield and fatigue capacity of the strengthened girder. Before and after the strengthening, the bridge was loaded with a 45-ton crane to assess the efficiency and performance of the system. Laboratory experiments were performed to optimize the mechanical anchors and examine the feasibility of the proposed strengthening method prior to application to the bridge. Finally, long-term monitoring of the prestressed Fe-SMA plates after installation on the bridge was conducted. The results showed that the main loss of the prestressing force caused by relaxation occurred within the first 30 days after activation and was approximately 20% of the original prestress.

KW - Bridge

KW - Phase transformation

KW - Prestressed strengthening

KW - Recovery stress

KW - Repair

KW - Shape memory alloy

KW - Strengthening

UR - http://www.scopus.com/inward/record.url?scp=85115767968&partnerID=8YFLogxK

U2 - 10.1016/j.engstruct.2021.113231

DO - 10.1016/j.engstruct.2021.113231

M3 - Article

AN - SCOPUS:85115767968

VL - 248

JO - Engineering structures

JF - Engineering structures

SN - 0141-0296

M1 - 113231

ER -