Abstract
Flexural behavior of reinforced concrete beams was affected by the shear span-to-depth ratio (a/d), but a/d was not mentioned in design guidelines for the steel fiber-reinforced concretes (SFRCs). This study covers the effect of a/d (from 1.0 to 5.5) on the failure behavior of FRC beams, in order to find a limiting a/d for effective beam depth and fiber length selection. Results showed that plain concrete beams failed in shear-flexure, SFRC beams (a/d greater than 2.5) failed in pure flexure with multicracking, SFRC beams (a/d less than 2.5) failed in shear-flexure. Therefore, a/d ratio has a significant effect on different failure behavior of SFRC beams.