PMID- 30966599
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200930
IS  - 2073-4360 (Electronic)
IS  - 2073-4360 (Linking)
VI  - 10
IP  - 6
DP  - 2018 May 23
TI  - Behaviour of Prestressed CFRP Anchorages during and after Freeze-Thaw Cycle 
      Exposure.
LID - 10.3390/polym10060565 [doi]
LID - 565
AB  - The long-term performance of externally-bonded reinforcements (EBR) on reinforced 
      concrete (RC) structures highly depends on the behavior of constituent materials 
      and their interfaces to various environmental loads, such as temperature and 
      humidity exposure. Although significant efforts have been devoted to 
      understanding the effect of such conditions on the anchorage resistance of 
      unstressed EBR, with or without sustained loading, the effect of a released 
      prestressing has not been thoroughly investigated. For this purpose, a series of 
      experiments has been carried out herein, with concrete blocks strengthened with 
      carbon fiber-reinforced polymer (CFRP) strips, both unstressed, as well as 
      prestressed using the gradient anchorage. The gradient anchorage is a 
      non-mechanical technique to anchor prestressed CFRP by exploiting the accelerated 
      curing property of epoxy under higher temperatures and segment-wise 
      prestress-force releasing. Subsequently, strengthened blocks are transferred into 
      a chamber for exposure in dry freeze-thaw cycles (FTC). Following FTC exposure, 
      the blocks are tested in a conventional lap-shear test setup to determine their 
      residual anchorage resistance and then compared with reference specimens. Blocks 
      were monitored during FTC by conventional and Fabry(-)Perot-based fiber optic 
      strain (FOS) sensors and a 3D-digital image correlation (3D-DIC) system during 
      gradient application and lap-shear testing. Results indicate a reduction of 
      residual anchorage resistance, stiffness and deformation capacity of the system 
      after FTC and a change in the failure mode from concrete substrate to 
      epoxy-concrete interface failure. It was further observed that all of these 
      properties experienced a more significant reduction for prestressed specimens. 
      These findings are presented with a complementary finite element model to shed 
      more light onto the durability of such systems.
FAU - Harmanci, Yunus Emre
AU  - Harmanci YE
AUID- ORCID: 0000-0002-6739-218X
AD  - Institute of Structural Engineering, Department of Civil, Environmental & 
      Geomatic Engineering, ETH Zurich, 8049 Zurich, Switzerland. 
      harmanci@ibk.baug.ethz.ch.
AD  - Structural Engineering Research Laboratory, Swiss Federal Laboratories for 
      Materials Science and Technology, Empa, 8600 Dubendorf, Switzerland. 
      harmanci@ibk.baug.ethz.ch.
FAU - Michels, Julien
AU  - Michels J
AUID- ORCID: 0000-0002-9689-0890
AD  - Structural Engineering Research Laboratory, Swiss Federal Laboratories for 
      Materials Science and Technology, Empa, 8600 Dubendorf, Switzerland. 
      Julien.Michels@empa.ch.
AD  - re-fer AG, 6440 Brunnen, Switzerland. Julien.Michels@empa.ch.
FAU - Chatzi, Eleni
AU  - Chatzi E
AUID- ORCID: 0000-0002-6870-240X
AD  - Institute of Structural Engineering, Department of Civil, Environmental & 
      Geomatic Engineering, ETH Zurich, 8049 Zurich, Switzerland. 
      chatzi@ibk.baug.ethz.ch.
LA  - eng
GR  - Project No.124401/Swiss National Science Foundation/
PT  - Journal Article
DEP - 20180523
PL  - Switzerland
TA  - Polymers (Basel)
JT  - Polymers
JID - 101545357
PMC - PMC6404005
OTO - NOTNLM
OT  - CFRP
OT  - bond behavior
OT  - durability
OT  - epoxy
OT  - fiber optic sensors
OT  - finite element modeling
OT  - freeze-thaw-cycles
OT  - prestressing
OT  - structural strengthening
OT  - swelling
COIS- The authors declare no conflict of interest.
EDAT- 2019/04/11 06:00
MHDA- 2019/04/11 06:01
PMCR- 2018/05/23
CRDT- 2019/04/11 06:00
PHST- 2018/03/01 00:00 [received]
PHST- 2018/05/09 00:00 [revised]
PHST- 2018/05/17 00:00 [accepted]
PHST- 2019/04/11 06:00 [entrez]
PHST- 2019/04/11 06:00 [pubmed]
PHST- 2019/04/11 06:01 [medline]
PHST- 2018/05/23 00:00 [pmc-release]
AID - polym10060565 [pii]
AID - polymers-10-00565 [pii]
AID - 10.3390/polym10060565 [doi]
PST - epublish
SO  - Polymers (Basel). 2018 May 23;10(6):565. doi: 10.3390/polym10060565.