| In recent years, the fiber-reinforced polymer (FRP) has been attracting people's attention due to its excellent mechanics properties, It is widely used for the reinforcement of concrete structure and other structures. And it is expected to be used for blast-resistance retrofit of protective structure and seismic retrofit of the ordinary structure. However there are few researches about mechanical performance of FRP confined concrete under rapid loading. This paper aims to make people further understand the static performance and mechanical performance of FRP confined concrete under rapid loading. This paper mainly deals with the experiment research and theoretical analysis through 64 (25 sets) cylinderical columns testing under monotony quasi-static (0.00001/s) loading, monotony rapid (0.0149/s~0.357/s) loading, rapid (0.0149/s) repeated loading with equal strain amplitude. Also it adopts finite element software ABAQUS to conduct the static analysis of GFRP confined concrete. The simulation is as similar as the experiment ones.Compared with plain concrete column, the ultimate strength of FRP confined concrete under quasi-static loading has improved significantly. And with increasing of packages, it presents a linear growth. with the improvement of the concrete strength, the ultimate strength did not show a trend to gradual increase, although under various intensities ultimate strength has improved to some extent. And under quasic-static conditions, ultimate strain of confined concrete has a considerable degree of increase comparing with plain concrete, that is the ductility have an improvement and be advantageous to an anti-earthquake. The reason of FRP confined concrete's strength improvement lies in: FRP hoops restraint concrete and force concrete in three-dimensional compression conditions so as to improve the strength of concrete.Ultimate strength of FRP confined concrete under rapid loading increases along with increasing of strain rate and has linear relationship with logarithmic strain rate, but the slopeα(which is defined strain rate susceptive coeffcient of ultimate strength on FRP confined concrete under rapid loading)has no linear relationship with constraint ratioξ, gradually converges. Ultimate strain of FRP confined concrete under rapid loading increases along with strain rate increasing and has linear relationship with logarithmic strain rate. The slopeβ(which is strain rate susceptive coefficient of ultimate strain on FRP confined under rapid loading)has linear relationship with constraint ratioξ. The original elastic modulus of FRP confined concrete under rapid loading is basically as same as the one under the condition of static loading.Stress-strain curve of FRP confined concrete under rapid loading shows clearly smooth curve character, and has obvious difference in comparison to coupled linear characteristic under quasi-static loading.Under rapid repeated loading with lager amplitude,"Resistance"and round stiffness of FRP confined concrete reduces a little and gradually converges. After repeated loading quasi-static test of FRP confined concrete shows that the stress-strain curve is different from the one under monotony loading, its elastic modulus decreases much, especially for the FRP confined concrete,however this doesn't influence on the ultimate strength, the ultimate strain increases. All this performance show that it is feasible to apply FRP confined concrete to the retrofit of blast-resistance protective structure and seismic retrofit of building structure.Based on damage theory, this paper theoretically analyses the damage process and damage mechanism of FRP confined concrete under rapid and rapid repeated loading with lager amplitude. Through analysis we find that plasticity damage model should be used to the FRP confined concrete analysis, this model can be better used to describe the evolution of damage.Using finite element software ABAQUS for FRP confined concrete for static loading analysis, the experimental value matches well with the simulation value.
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