For simplicity, stirrups were not considered as a geometrical entity but its effect was considered by introducing a confined concrete
model for the RC.
An analytical model for stress-strain behavior of confined concrete
, Journal of Engineering Structures 27: 1040-1051.
Theoretical Stress-Strain Model for Confined Concrete
, Journal of Structural Engineering ASCE 114(8): 1804-1826.
They reported that FRP confined concrete
increased the strength and ductility of the column.
Equations (1) and (2) have been used to respectively obtain the confined concrete
compressive strength [f.
Most of the results for FRP confined concrete
and theoretical models published in the literature are based on short stubs for which slenderness ratio is very minimal.
International Symposium on Confined Concrete
(2004: Hunan University) Ed.
Then one uses a notion of constructional coefficient of tube confined concrete
[rho], calculated by the formula
2008) performed 46 tests on thin-walled steel tube confined concrete
stub columns subjected to axial compression to assess effects of sectional type, local compression area ratio and steel tube width-to-wall thickness ratio on the behaviour of the columns.
Deniaud and Neale (2006) observed a good agreement between the elasto-plastic analysis of FRP-steel confined concrete
columns with the D-P yield criterion and experimental data.
Assumption (5) is not exact but however a fairly reasonable assumption in the sense that: (i) at small concrete strains, the variation of confining pressure would not have significant effect on the confined concrete
stress (Attard and Setunge 1996); (ii) when the extreme fibre of confined concrete
reaches about 0.
the increase in ductility of confined concrete
is related to the stiffness of the confining device.