Compressed Concrete-Filled Steel Tube Elements with Indirect Reinforcement of the Concrete Core

Abstract

The purpose hereof is to study the specifics of the force resistance and to experimentally identify the reinforcement effect of short square-section concrete-filled steel tube elements (CFSTE) with spiral reinforcement. Analysis of the laboratory samples of concrete-filled steel tube columns shows that spiral reinforcement makes them stronger by 18÷43% depending on the source concrete class. Maximum recorded longitudinal deformation in spiral-reinforced samples is 1.7÷2 times larger. Using a relatively small amount of spiral reinforcement (about 1%) has resulted in a mean 23% stronger reinforcement effect in the studied structures. Such structures remain efficient when using high-strength concrete.