Steel Fiber Reinforced High Strength Concrete Beam Flexural Performance

Steel fiber reinforced high-strength concrete is a new building material with excellent properties. It not only makes the best use of the strength of concrete, it also improves mechanical performance of high-strength concrete. This paper researchs on the bend behavior of twelve steel fiber reinforced high-strength concrete beams. The calculating formulas which suit steel fiber reinforced high-strength concrete beams are presented. The main contents are as follows:1 , The development and the use in fact of fiber concrete, high-strength concrete , steel fiber reinforced high-strength concrete and the enganced theory of steel fiber (the theory of fiber space between and the theory of multiple mechanics) are expounded. The main research contents and research methods are introduced.2, By means of the research of the test beams, Variables of the volume fraction of steel fiber, the ratio of longitudinal reinforcement, the height of the beam and the category of reinforcing steel bar that affect the normal cross sectional strength properties, the failure mode and the flexural capacity of steel fiber-reinforced high-strength concrete beams are analysed. The formula for calculating normal section strength of flexural steel fiber-reinforced high-strength concrete beams is put forward, which is connected with those of steel fiber reinforced plain concrete beams and high-strength concrete beams.3 , The various factors of the volume fraction of steel fiber , the ratio of longitudinal reinforcement, the height of the beam and the category of reinforcing steel bar affecting crack-resistant moment of steel fiber-reinforced high-strength concrete beams are studied. The formula for calculating crack-resistant moment of steel fiber-reinforced high-strength concrete beams is presented, which is connected with criterion of putting in practice.4, The development of the cracks in the whole loading course are described and contrasted. The factors of the volume fraction of steel fiber, the ratio of longitudinal reinforcement, the height of the beam and the category of reinforcing steel bar affecting the development of the cracks and the width of the biggest crack in steel fiber-reinforced high-strength concrete beams are researched, and analyse the affecting factors consulting with crack pictures. According to the criterion of China, the formula for calculating the width of the biggest crack of steel fiber-reinforced high-strength concrete beams is established.5, The various factors of the volume fraction of steel fiber, the ratio of longitudinal reinforcement, the height of the beam and the category of reinforcing steel bar affectingload-deflection curves of steel fiber-reinforced high-strength concrete beam are analysed. On the basis of the criterion of China, the formula for calculating flexural rigidity of steel fiber-reinforced high-strength concrete beams is put forward.