Probability Distribution and Recommended Value of Steel Fiber Impact Coefficient in the Tensile Zone of Reinforced Concrete Beams

The 18 steel fiber reinforced concrete (SFRC) beams and one reinforced concrete (RC) beam with high strength steel bars were investigated by means of flexural experiments.The test variables were concrete strength,steel bar strength,steel fiber volume fraction,steel fiber end hooks number,depth ratio of SFRC in tensile zone and longitudinal tensile reinforcement ratio.The applicability of the steel fiber impact coefficient in current code of China for the calculation of flexural capacity of SFRC beam with high strength steel bars was also discussed,of which the impact coefficient value was used to reflect the influence of steel fiber on the flexural capacity of SFRC beams.Test results indicated that the flexural capacity of RC beam with high strength steel bars improved effectively with the addition of steel fibers.The value of steel fiber impact coefficient in the tensile zone of SFRC beams with high strength steel bars is relatively small while compared with that in current code of China.The probability distribution of steel fiber impact coefficient was emphatically analyzed through the experimental data collecting from relevant literatures,and the steel fiber impact coefficients for the different types of steel fibers with various guarantee rates were achieved.Finally,the suggestion for the value of steel fiber impact coefficient in the tensile zone of SFRC beams was proposed,which could be referred for the code revision.