Modeling of Fundamental Behavior of Pre-stressed FRP-Confined Concrete and Its Stress-Strain Curve

One of the structural elements with a vital role in bearing axial load is the columns. Experience after erthquakes show that the lack of adequate reinforcement is a major cause of failure of columns. So an effective technique to enhance the strength of seismically deficient concrete columns is to provide additional lateral confinement. tow general types of confinement are passive and active confinement. confinement by spirals or ties is passive and is mobilized by resisting expansion due to the possion’s effect. but fluid pressure, for example, in a tri axial cell provides active confinement. Hence, passive confinement is not constant and is dependent on the lateral dilation of the concrete under axial load and stress-atrain relationship of the confining materials. lateral confinement can be produced by using of various types of lateral confinement such as steel and the new composite materials using these two metallic and non-metallic materals will be presented. After that the experimental work of pre-stressing of FRP jackets will be discussed which is an original work done in sheffield university, UK. finally, the analytical model and reationships between the amount of confinement and pre-stressing force will be considered and compared to the experimental results. It is worth mentioning that verification and comparoson the results obtained here with those of finite element method may be presented in the subsequent studies.

کلیدواژه ها:

optimized confinement ، FRP jacket ، stress-strain curve ، pre-stressing