Effectiveness of FRP Jackets for the Confinement of Existing RC Bridge Piers with Hollow Cross-Section

The objective of the research presented in this paper is to examine the effectiveness of fibre-reinforced polymer (FRP) jackets for the enhancement of the deformation capacity of RC bridge piers with large hollow cross-section. A two-level numerical approach is proposed in order to study the effect of axial load, longitudinal reinforcement ratio and jacket dimensions. The numerical study consists of analysis of a rectangular hollow concrete cross-section wrapped with an FRP jacket using the Finite Element Method (FEM), with the aim of studying the effect of confinement on the properties of concrete, and of moment–curvature analysis of a fibre model of a RC cross-section, where the properties of concrete were modified according to the results of the FEM study. A few recent experimental campaigns indicate that hollow piers retrofitted with FRP strips show higher deformation and energy-dissipation capacity compared to their as-built counterparts. FEM analyses showed that the stress-strain curve of FRP-confined concrete in hollow cross-sections comprises a post-peak softening branch, with a slope less steep than the one for unconfined concrete, contrary to bilinear empirical laws. Confinement was not uniform within the cross-section. The results showed that a complex relation holds between the examined geometric and mechanical characteristics of the cross-section and curvature ductility, with axial load being a determinant parameter.

TSIONIS Georgios;  PINTO VIEIRA Artur; 

2007-07-23

University of Patras

JRC34889

https://publications.jrc.ec.europa.eu/repository/handle/JRC34889,