Behavior of Steel Fiber-Reinforced Concrete under Biaxial Stresses

Biaxial behavior of various types of concrete is essential to be considered in construction design because construction structures normally experience multiaxial stresses rather than uniaxial stress. Research on biaxial behavior of steel fiber-reinforced concrete (SFRC) has been conducted in the past decades. Most of the research, however, is only limited to biaxial compression, whereas information regarding biaxial tension and biaxial tension-compression on SFRC is relatively scarce. This study presents a simple biaxial experimental setup to investigate the biaxial behavior of SFRC with 0.5, 1.0, and 1.5% steel fiber under biaxial tension and biaxial tension-compression. It is found that the smaller stress ratio enhanced the deformability and tensile capacity of SFRC under biaxial tension-compression, whereas the effect of stress ratio on biaxial tensile behavior of SFRC is negligible. The addition of steel fiber eventually enhanced the concrete strength by 15 to 41% under tension-compression compared with plain concrete.