Fiber Interfacial Transition Zone Concept for Steel Fiber-Reinforced Concrete by SEM Observation

Fiber-reinforced concrete (FRC), which has become quite popular in recent years, improves many of concrete’s mechanical properties. It uses fibers discretely and is utilized different structures. This paper proposes, between steel concrete, a fiber interfacial transition zone (FITZ) the most vulnerable part FRC (SFRC) because it high cracking microcracking potential due to fiber-concrete separation. In prepared specimens, were added hooked twisted forms, SFRC microstructure was studied both cases under scanning electron microscope (SEM), related images compared as secondary (SE) images. The SEM analysis showed highly precise cracks their microstructures FITZ lab results show that newly defined illustrates patterns well for types. Because have angles larger contact surfaces, concrete-fiber bond increased crack widths decrease considerably. A comparison those specimens with decreased by factor approximately seven fibers.