A study on the flexural behavior of fiber-reinforced concrete beams subjected to tensile steel corrosion

This paper presents the results of an experimental study on the flexural performance of reinforced concrete beams made of fibrous concrete under the corrosion of tensile steels. Fifteen reinforced concrete beams were prepared in three groups; in two groups, two types of steel and polyolefin fibers were utilized to construct the beams. Four beams from each group were subjected to accelerated corrosion to create corrosion percentages of 3.5, 7, 15 and 30% in tensile steels. Then the beams were subjected to a four-point bending test, and the parameters of yield strength, ultimate strength, yield deflection, ultimate deflection, failure mode and ductility of the beams were investigated. The results indicated that up to the corrosion level of 15%, with the development of general corrosion, along with the reduction of stiffness and resistance of the beams, the ultimate deflection of the beams increased, and at the corrosion level of 30%, with the development of local corrosion, the ultimate strength and ultimate deflection of the beams were greatly reduced. The level of corrosion in tensile steel of beams containing steel fibers was lower than that of in the other beams, which was caused by the sacrificial anode effect of steel fibers. Under the corrosion conditions of tensile steel, the reduction of strength and stiffness in fibrous concrete beams were less than those in the plain concrete beams, and the performance of steel fibers in this field was significantly better than their polyolefin counterparts. Furthermore, the fibers used for this purpose, had significantly positive effect on the ductility of reinforced concrete beams with tensile steel corrosion.