Roads and Bridges - Drogi i Mosty
16, 2, 2017, 85-99

Strengthening of steel structures with CFRP strips

Maciej Kowal Mail
Lublin University of Technology, Civil Engineering and Architecture Faculty, 40 Nadbystrzycka Street, 20-618 Lublin
Marek Łagoda Mail
Road and Bridge Research Institute, 1 Instytutowa Street, 03-302 Warsaw
Published: 2017-06-30


The paper presents the results of research on the suitability of externally bonded composite strips of carbon fibre-reinforced polymer (CFRP) for post-strengthening of steel structures. Specimens with the strips applied on both sides (double cover joints) were prepared and subjected to axial tension tests to find which of the eight different configurations of end detailing provides the strongest bond. The strengthening effect of externally bonded composite strips was tested on sixteen steel I-beams, including determination of the effective bond length and the effects of the thickness of adhesive layer and modulus of the CFRP strip on the load capacity of the steel-adhesive-CFRP strip assembly. The research showed that externally adhered CFRP strips can increase the bending strength of steel structures (an 8% increase was obtained in the experiments) and the shape of spew fillet can have a significant influence on the strength of the strengthened system (the difference reaching up to 57%).


end detailing, FRP composites, steel structures, strengthening

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Strengthening of steel structures with CFRP strips

Kowal, Maciej; Łagoda, Marek. Strengthening of steel structures with CFRP strips. Roads and Bridges - Drogi i Mosty, [S.l.], v. 16, n. 2, p. 85-99, jun. 2017. ISSN 2449-769X. Available at: <>. Date accessed: 15 Dec. 2019. doi: