Mixed Mode Fracture in Reinforced Concrete with Low Volume Fraction of Steel Fibers

An investigation into the mixed mode fracture of steel fiber reinforced concrete (SFRC)beams with one percent volume fraction of steel fiber is presented. A series of notched beams withdifferent notch depths and locations are tested under three-point bending. The test results for apparentfracture toughness, crack trajectories, and fracture energy are presented. The crack paths for SFRCand plain concrete beams are compared. The apparent fracture toughness values were more scatteredfor SFRC than for plain concrete. The load-deflection curves were used to obtain the fracture energy.To this end, two methods were utilized for center notched beams, and the results were comparable toeach other. It is observed that fracture energy is a more reliable material property than apparentfracture toughness, and its scatter is less.