Finite element analyses of FRP-strengthened concrete beams with corroded reinforcement
Journal article, 2022

Existing deteriorated reinforced concrete (RC) structures need strengthening to extend service life. Fibre reinforced polymer (FRP) has been widely used to strengthen sound structures, but its application on damaged concrete structures still needs to be investigated. This paper presents non-linear finite element analyses conducted to assess the flexural behaviour of corrosion-damaged RC beams strengthened with externally bonded FRP. Beams in four different categories were analysed: a reference beam, a corroded but non-strengthened beam, and corroded beams strengthened with glass FRP (GFRP) and carbon FRP (CFRP) respectively. Furthermore, the strengthened beams were modelled with different modelling choices to investigate the effectiveness of FRP applied to the beam soffit and as U-jackets. Pre-loading and corrosion-induced cracks were incorporated by reducing the tensile strength of concrete elements at crack locations. Average and pitting corrosion were incorporated by reducing the cross-sectional area of the reinforcement corresponding to the measured corrosion levels. Interface elements were used to simulate the bond between FRP and concrete. The modelling methods were validated against experimental results. It was found that modelling of pitting corrosion, especially the location of pits, lengths and number of pits considered, were influential in predicting the load and deformation capacity of beams. A CFRP plate at the beam soffit, combined with inclined U-jackets at its ends of the CFRP plate provided sufficient flexural strengthening. Thus, intermediate U-jackets did not further increase the load-bearing capacity for the studied beam geometry and corrosion damages. However, with a GFRP sheet at the beam soffit, both inclined and intermediate U-jackets were needed to provide full utilisation of the GFRP sheet for the studied beam geometry. In further studies of the effectiveness of the strengthening methods, it is recommended to investigate beams of varying dimensions, corrosion patterns and levels, and FRP spacing and dimensions.

Strengthening

Reinforced concrete structures

Cracks

Corrosion

CFRP

Fibre-reinforced polymer

Finite element analysis

U-jacket

Interface

GFRP

Author

Milan Gotame

Student at Chalmers

Carl Lindqvist Franklin

Student at Chalmers

Mattias Blomfors

Chalmers, Architecture and Civil Engineering, Structural Engineering

Bridge and Analysis group

Jincheng Yang

Chalmers, Architecture and Civil Engineering, Structural Engineering

Karin Lundgren

Chalmers, Architecture and Civil Engineering, Structural Engineering

Engineering Structures

0141-0296 (ISSN) 1873-7323 (eISSN)

Vol. 257 114007

Repair and strengthening of concrete structures with corroded reinforcement

Swedish Transport Administration (TRV2019/64827), 2019-08-01 -- 2022-09-30.

Subject Categories

Applied Mechanics

Infrastructure Engineering

Building Technologies

Composite Science and Engineering

DOI

10.1016/j.engstruct.2022.114007

More information

Latest update

12/22/2022