钢筋钢纤维高强混凝土梁正截面开裂弯矩的计算方法

Calculating Method for Crack-resistant Moment of Steel Fiber Reinforced High-strength Concrete Beams with Reinforcement

通过12根钢筋钢纤维高强混凝土梁的试验,分析钢纤维对钢筋高强混凝土梁正截面抗裂弯矩的影响.实验结果表明,钢纤维的加入提高了钢筋高强混凝土梁的正截面开裂弯矩,并随着钢纤维体积率的增加呈增长的趋势,增加幅度在40%～100%之间;纵向钢筋配筋率、梁的高度以及钢筋的强度等级对钢筋高强混凝土梁的开裂弯矩也有影响;开裂弯矩随纵筋配筋率的增大以及随截面高度的减小而增大.结合现行有关规范,提出了钢筋钢纤维高强混凝土梁截面抵抗塑性影响系统的计算公式和钢筋钢纤维高强混凝土梁开裂弯矩的计算公式,并用试验数据验证了该公式的正确性.

Based upon the tests on 12 steel fiber reinforced high- strength concrete beams with reinforeements, the effect of steel fiber on the normal cross sectional crack - resistant moment of steel fiber reinforced high - strength concrete beams is analysed. The test results show that the normal cross sectional crack - resistant moment increases with the increase of steel fiber volume ratio, and the longitudinal reinforcement ratio, the height of beam and reinforcement grade have the impact on the crack - resistant moment. Together with the criterion of China, the formula for calculating crack - resistant moment of steel fiber reinforced high - strength concrete beams is presented, and the correctness of the formula is validated by the test data.