Simulation of flexural performance of mill-cut steel fiber reinforced concrete beam degraded by mild corrosion

The reinforced concrete structure is widely used for various applications structure due to its many advantages, so it is easily exposed to severe environments and corrosion of steel occurred shortening the life durable of the structure which may cause danger to humans and economic damage. Corrosion occurred as a significant factor leading to the further deterioration of performance and reduction of the loading resistance of reinforced concrete structures. Therefore, durable corroded structures should be dealt with to ensure user safety. In recent decades, steel fiber reinforced concrete is studied and applied cause of provides better durability. Nevertheless, there is a limitation to studying the durability of SFRC under corrosive conditions. Consequently, this research aims to appraise the effectiveness of utilizing steel fiber reinforced concrete (SFRC) for its application in normal conditions and in a chloride environment. At the first objective, the mill-cut steel fiber having a rough surface and twist along the length with various volume fractions was trialed with the plain concrete of 40 MPa compressive strength to provide a good mixture for full-scale SFRC beams. Twelve beams were fabricated and examined under four-point bending with the volume fractions of fiber were 0, 0.5%, 1.0%, and 1.5% including four beam control without corrosion, and 8 beams were subjected to 2% and 5% corrosion of tensile bar, respectively by applying acceleration technique. The results attained from the experimental program illustrated that an insignificant improvement ultimate load capacity of normal SFRC beams was observed with growth is only 10%. An increasing degree of corrosion of steel led to a larger reduction of load capacity of the RC beams, there was an approximately 21% of decline at an ultimate load resistance of the beam loss of 5% of the mass of reinforcement whilst the yield load capacity was more damaged with a decrease by 27.4%. Nevertheless, this reduction could be maintained with sufficient steel fiber utilized especially for the case with a greater degree of corrosion as 5%. When the RC beam lost 2% of tensile reinforcement, utilizing the SFRC was marginally efficient in the flexural performance since the improvement is around 15% for both yield and ultimate load. However, this growth of ultimate load carrying for group 5% corrosion was found is varied from 17% to 39% proportionally to the volume fraction of fiber from 0.5% to 1.5% compared to the plain corroded RC beam. Then the simulation flexural behavior of corroded SFRC beam was performed by the ANSYS mechanical ADPL package. The nonlinear finite element analysis model by using nonlinear material properties from the experimental that could predict the load-displacement relationship of corroded SFRC well with the maximum difference of less than 10% in terms of load capacity of the beam.