{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T12:18:39Z","timestamp":1791461919915,"version":"4.3.4"},"reference-count":38,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2020,11,28]],"date-time":"2020-11-28T00:00:00Z","timestamp":1606521600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Over the last 30 years, structural reinforcement and retrofitting with externally bonded composite materials have proven to be efficient and cost-effective solutions to increase both the safety and the lifespan of civil engineering structures, including nuclear power plants. The effectiveness of the strengthening system highly depends on the level of adhesion between the fiber-reinforced polymer (FRP) composite material and the concrete surface. Therefore, on-site evaluation of the bond quality is critical to assess the performance and predict the durability of the system in place. The direct tension pull-off test is most commonly used to quantify the adhesion level, but this standardized method has many drawbacks. In the present study, it is proposed to evaluate the bond properties by using a nondestructive test (NDT) derived from the standard pull-off test. This innovative test enables the measurement of an interfacial \u201cstiffness\u201d which may be used as a bond quality criterion. This paper gives an insight into the performance of the proposed NDT method, when applied in laboratory conditions to concrete slabs reinforced with bonded pultruded carbon FRP plates (CFRP). Three different epoxy adhesive systems with a broad range of Young\u2019s moduli were used for the specimens\u2019 preparation, in order to vary the stiffness of the concrete\/CFRP interface. The purpose was to simulate different levels of interfacial adhesion that could be observed for a single adhesive system. It was shown that the test method was able to detect differences in the interface stiffness beyond experimental uncertainties, and it should therefore enable the detection of differences in the bond quality for a given adhesive system as well. The sensitivity of the NDT was then discussed, and its detection capabilities were predicted for standard field conditions. In the last part, strain measurements were collected during the NDT, thanks to distributed optical fiber sensors (DOFS) embedded in the adhesive joints of the strengthened specimens. An analysis of the strain profiles was found to provide complementary information on the quality of the adhesive bond.<\/jats:p>","DOI":"10.3390\/ma13235421","type":"journal-article","created":{"date-parts":[[2020,11,29]],"date-time":"2020-11-29T21:00:57Z","timestamp":1606683657000},"page":"5421","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Development of an Innovative Non-Destructive and Field-Oriented Method to Quantify the Bond Quality of Composite Strengthening Systems on Concrete Structures"],"prefix":"10.3390","volume":"13","author":[{"given":"Astrid","family":"Billon-Filiot","sequence":"first","affiliation":[{"name":"Electrotechnique et M\u00e9canique des Structures (ERMES) Department, R&amp;D Division, Electricit\u00e9 de France (EDF), 91120 Palaiseau, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6249-2616","authenticated-orcid":false,"given":"Fr\u00e9d\u00e9ric","family":"Taillade","sequence":"additional","affiliation":[{"name":"Performance, Risque Industriel et Surveillance pour la Maintenance et l\u2019Exploitation (PRISME) Department, R&amp;D Division, EDF, 78400 Chatou, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6199-0499","authenticated-orcid":false,"given":"Marc","family":"Quiertant","sequence":"additional","affiliation":[{"name":"Mat\u00e9riaux et Structures (MAST) Department, Universit\u00e9 Gustave Eiffel\u2014Institut Fran\u00e7ais des Sciences et Technologies des Transports, de l\u2019Am\u00e9nagement et des R\u00e9seaux (IFSTTAR), 77454 Marne-la-Vall\u00e9e, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Marie","family":"H\u00e9nault","sequence":"additional","affiliation":[{"name":"Performance, Risque Industriel et Surveillance pour la Maintenance et l\u2019Exploitation (PRISME) Department, R&amp;D Division, EDF, 78400 Chatou, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Claude","family":"Renaud","sequence":"additional","affiliation":[{"name":"Mat\u00e9riaux et Structures (MAST) Department, Universit\u00e9 Gustave Eiffel\u2014Institut Fran\u00e7ais des Sciences et Technologies des Transports, de l\u2019Am\u00e9nagement et des R\u00e9seaux (IFSTTAR), 77454 Marne-la-Vall\u00e9e, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Romain","family":"Maurin","sequence":"additional","affiliation":[{"name":"Mat\u00e9riaux et M\u00e9canique des Composants (MMC) Department, R&amp;D Division, EDF, 77250 Ecuelles, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1304-5868","authenticated-orcid":false,"given":"Karim","family":"Benzarti","sequence":"additional","affiliation":[{"name":"Laboratoire Navier, Universit\u00e9 Gustave Eiffel\u2014Ecole Nationale des Ponts et Chauss\u00e9es (ENPC), Centre National de la Recherche Scientifique (CNRS), 77447 Marne-la-Vall\u00e9e, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"120733","DOI":"10.1016\/j.conbuildmat.2020.120733","article-title":"Transversal joining of multi-leaf masonry through different types of connector: Experimental and theoretical investigation","volume":"265","author":"Cascardi","year":"2020","journal-title":"Constr. 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