Shear strengthening applications

Figures 4.17 and 4.18 show examples of applications of FRP for shear strengthening. Figure 4.19 shows schematically a selection of some...

Steel Under Earthquake Excitations Reinforcing steel in external reinforced crmcrete jackets for the retrofit and strengthening of existing reinforced concrete or steel members comes mainly in the form of bars. Usually, the stress-strain behavior under tension-compression is cmcial to assess the longitudinal bars contribution. The stress-strain behavior under tension is of interest for the transverse reinforcement (stirmps). Steel dowels and stud shear connectors may involve shear (or tensile) behavior of steel- or bond-related issues. External steel plates may be considered under multiaxial loading (i.e., in cases of shear strengthening in order to estimate their yield stress). Bond-related issues may concern bar-concrete interfaces, bar-resin-concrete interfaces (NSM applications), or plate-resin-concrete interfaces under cyclic loading. 

Active confinement with FRPs (filament, straps, or composite shells) is a viable alternative to metal ones as presented in numerous applications. Beneficial effects of xmbonded prestressed FRPs on shear strengthening of beams have been identified also in Lees et al. (2002). 

In this chapter, informative discussions, explanations and verifications have been presented on the issue of stresses, their categories, significance and characterization in FRP strengthened civil applications. Throughout the chapter, particular emphasis has been given to the lap-shear and normal stresses within the interfacial adhesive layer of externally bonded FRP/steel adherends, since this component (i.e. interfacial adhesive) and adherend (i.e. steel) of such FRP joints represent, in terms of these stresses, the most likely failure location and ultimate capacity of FRP adhesive joints, respectively. Some useful key conclusions can be drawn based on all the issues presented in this chapter ... 

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