Behavior and modeling of confined high-strength concrete

This paper presents a study on the behavior and modeling of the stress-strain behavior of confined high-strength concrete (HSC) without silica fume. The behavior of actively confined HSC is first examined, and a unified active-confinement model applicable to both HSC and normal-strength concrete (NSC) is then proposed based on a large test database assembled from the existing literature. An experimental study on fiber-reinforced polymer (FRP)-confined HSC is next presented and interpreted to examine its behavior, forming the basis for the subsequent modeling work. It is eventually shown that a recent analysis-oriented model developed by the writers' group for NSC also provides close predictions for FRP-confined HSC. While the work is primarily concerned with HSC without silica fume, the effect of incorporating silica fume into HSC on the behavior of confined HSC is also given appropriate attention. The presence of silica fume in HSC is shown to reduce the effectiveness of confinement in term of strain capacity.