混杂纤维自密实混凝土梁受弯性能的试验研究

在纤维自密实混凝土工作性试验的基础上,对7组无筋混杂纤维自密实混凝土梁和5组混杂纤维增强低配筋率的钢筋自密实混凝土梁受弯性能进行试验研究,并分析纤维类型和纤维长径比对梁的开裂荷载、屈服荷载、极限荷载以及弯曲韧性的影响。结果表明:梁的弯曲韧性随着纤维长径比的增加而增加,混杂纤维混凝土梁的弯曲韧性优于钢纤维,两种纤维协同作用时具有很好的正混杂效应;与最小配筋率的钢筋混凝土梁相比,纤维的掺入明显地改善了梁的屈服荷载和极限荷载,掺有(40+4)kg/m3混杂纤维并按最小配筋率配筋的梁的极限荷载与仅按1.5倍最小配筋率配筋的梁相当。

EXPERIMENTAL STUDY ON FLEXURAL BEHAVIOR OF HYBRID FIBER REINFORCED SELF-COMPACTING CONCRETE BEAMS

Based on the workability test of fiber reinforced self-compacting concrete,this paper presents the experimental study on flexural behavior of seven sets of hybrid fiber reinforced self-compacting concrete beams without reinforcement and five sets of hybrid fiber reinforced self-compacting concrete beams with low reinforcement ratios.The influence of fiber aspect ratio and fiber type on crack load,yield load,ultimate load and flexural toughness are analyzed.The results indicate that the flexural toughness increases with increasing of fiber aspect ratio.The flexural toughness of hybrid fiber reinforced self-compacting concrete beams is better than that of steel fiber,which indicates positive hybrid effect.Compared to RC beam with a minimum longitudinal reinforcement,the yield load and ultimate load of fiber reinforced RC beams are greatly improved.The ultimate load of 40 + 4 kg /m3 hybrid fiber reinforced RC beam with a minimum longitudinal reinforcement is similar to that of RC beam with 1.5 times of a minimum longitudinal reinforcement.