Investigation of reinforced concrete beams behavior of steel fiber added lightweight concrete

► Steel fibers added lightweight concrete and its effects on prismatic beams. ► Steel fibers increased bearing strength and ductility of reinforced concrete beams. ► Steel fiber addition increased toughness and ductility of prismatic concrete beams. ► The weight of the beam decreased by 42% with use of lightweight concrete. ► The significant role of fibers is resisting the formation and growth of cracks.