Steel Fiber Reinforced High Strength Concrete Beam Bending Performance Of The Pilot Study

High-strength steel fiber reinforced concrete is a new type of material, bearing the virtues of both fiber concrete and high-strength concrete. Compared with common strength concrete, its stiffness, ductility, crack resistance ability, and durability is improved. Aiming to revise the Specification for Design and Construction of Steel Fiber Reinforced Concrete Structures, the flexural behavior of high-strength steel fiber reinforced concrete beams is investigated. The following work has been done:1 Basic theories and computational methods for existing common fiber concrete are expounded and summarized. Regarding the unique characteristics of high-strength steel fiber reinforced concrete, corresponding calculated theory is given.2 Variables that affect bending capacity of high-strength steel fiber reinforced concrete beams are discussed. Two main affected factors, characteristic parameters of fiber and base strength of high- strength concrete, are analyzed. The calculated formula for bending capacity of high-strength steel fiber reinforced concrete beams is put forward.3 Various factors affecting the initial strength are studied, mainly considering the effect of the change of fiber parameters and increase of concrete strength. The formula for calculating the load at the first crack in beams subjected to bending is given.4 Variables that affect the width of cracks in high-strength steel fiber reinforced concrete beams under normal service conditions are studied. Corresponding to different types of fiber and high-strength concrete, the previous formulas for calculating width of cracks in fiber reinforced concrete members are revised.5 The deformation and short-term stiffness of beams are analyzed. Meanwhile, factors affecting the ductility of members are investigated, and a formula is proposed to estimate curvature of high-strength steel fiber reinforced concrete beams.