Experimental Studies And Numerical Analysis Of Fatigue Properties Of Steel Fiber Reinforced Concrete Beam

According to the concrete specification codes,7beam specimens have been designed and made:length3000mm, section size of300mm×150mm. The reinforcement is1.62%, and the design strength of the concrete is CF60. The experiment takes the stress level and the volume of steel fiber content as variables, the steel fiber volume ratio parameter included0%,0.5%,1%; and the stress levels are designed for0.7,0.6,0.5and0.4. Based on the fatigue test, the damage of the specimens and beam deflection, the bottom of the beam crack height, width, and flexural rigidity under different numbers of cyclic loading are studied in the paper. the main contents and conclusions can be stated as follows:(1) The flexural rigidity degenerated curves of steel fiber reinforced concrete beam and reinforced concrete beam are similar. Both of them present three stages. The point between the first one and the second one is obvious. The first stage occupies the5%～10%of the whole fatigue life; the second one occupies a large proportion of fatigue life. A certain dosage of steel fiber can restrain the development of concrete beam crack height and width, and improve the fatigue life of the reinforced concrete beam. When the fiber volume content are0%,0.5%and1%, as the fiber volume content increases, the fatigue life becomes longer.(2) After Comparing the S-N curve of steel fiber reinforced concrete beam, steel fiber concrete beam and reinforced concrete beam, the paper reaches the conclusion: the S-N curve of reinforced steel fiber concrete beam appears to be a linear relationship as the S-N curve of reinforced beam,Reinforced steel fiber reinforced concrete beam is suitable for the load condition of high stress level.(3) The simulation by software ANSYS shows similar result of the experiment. Comparing the data of various aspects, the result verifies that the prediction of fatigue life of reinforced steel fiber beam in high cvcle is feasible...