Jsce-sf6 limitations for shear tests and astm d5607 shear tests on fiber-reinforced concrete

Although several JSCE-SF6 tests have established the strength improvements caused by fiber reinforcement, it is unknown whether the measured strength improvements are caused by shear strength improvements (that is, Mode II), or by tensile or flexural strength improvement (Mode I). This paper provides a basic understanding of the state of stress: 1) in a JSCE-SF6 test; and 2) in an ASTM D5607 direct shear test, which has never been used earlier to investigate the shear strength of fiber-reinforced concrete (FRC). It was found that the JSCE-SF6 standard does not test the shear strength of a material, and it cannot be used to obtain shear characteristics of FRC. On the other hand, the ASTM D5607 standard can be used effectively to obtain shear characteristics of FRC because it creates a stress field very close to pure shear. The addition of steel fibers to concrete does not increase the peak shear strength of concrete.