To
establish compressive stress-strain models of concrete confined by fiber
reinforced polymer (FRP), test results of 304 FRP-confined concrete cylinders
have been collected from open literatures. The study of the test results shows
that when the fiber characteristic value of FRP sheet confined concrete
cylinders is less than 0.18, the axial compressive stress-strain curve has an
ascending branch as well as a descending branch. When the FRP tube and the
concrete core of FRP tube confined concrete cylinders are axially loaded
together, most of the existing models underestimate the initial modulus and
overestimate the ultimate strain of concrete. Two compressive stress-strain
models of FRP-confined concrete are proposed in this paper. One is hardening
model which consists of a parabolic section and a straight line, the other is
softening model which has a parabolic section only. Influences of fiber
characteristic value, FRP laminate structure and loading method on the models
have been taken into account.