Experimental study on shear properties of aligned steel fiber reinforced cement-based composites

Shear behavior is one aspect of the fundamental mechanical performance of steel fiber reinforced cement-based composites. In order to investigate the influence of fiber orientation on the shear properties of steel fiber reinforced cement-based composites, the shear behavior of aligned steel fiber reinforced cement-based composites (ASFRC) and conventional steel fiber reinforced cement-based composites with random distribution of steel fibers inside (SFRC) was experimentally compared using modified double-plane direct shear tests. In the tests, the shear displacement was recorded by LVDT and shear strain was determined by digital image correlation analysis (DIC). Then the shear load-displacement and stress-stain curves of the two series specimen were obtained. The results show that when the volume fraction of steel fiber in the range of 0.8-2.0%, the alignment of steel fibers causes the increase in shear strength, modulus and toughness up to 40%, 30% and 50%, respectively. A major reason is that when the steel fibers are aligned the number of the fibers bridging the cracked shear section is increased and the fiber spacing is reduced.