玄武岩纤维复材筋混凝土梁受弯性能试验研究

EXPERIMENTAL RESEARCH ON FLEXURAL PERFORMANCE OF BFRP REINFORCED CONCRETE BEAMS

利用玄武岩纤维(BFRP)复材筋等强度替代钢筋、等截面替代钢筋以及与钢筋混合配筋形式制作混凝土简支梁,对其进行受弯性能试验,研究不同配筋形式和不同配筋率对梁受弯性能的影响,分析混凝土简支梁的跨中挠度、裂缝分布及宽度、受拉筋应变和承载力,通过对比试验值和理论值,分析试验梁破坏模式。结果表明:在相同荷载作用下,BFRP筋混凝土梁的挠度大于钢筋混凝土梁,而混合配筋混凝土梁介于两者之间;相同配筋率时,BFRP筋混凝土梁的承载力比钢筋混凝土梁的承载力低,尽管BFRP筋没有明显的屈服点,但混合配筋混凝土梁仍表现出较好的延性,为受压区混凝土压碎破坏,在梁完全破坏前提供明显的预兆,破坏模式为适筋破坏;BFRP筋混凝土梁和混合配筋混凝土梁的截面都基本满足平截面假定。

Bending performance test was carried out on BFRP reinforced concrete simply supported beams with equal-strength replacement steel bars,beams with equal-section replacement steel bars,hybrid bars beams with BFRP bars and steel bars.The influence of different reinforcement forms and different reinforcement ratios on the bending behavior of the beams were studied.The mid-span deflection,crack distribution and width,tensile strain and bearing capacity of the simply supported beams were analyzed.The failure mode of test beams was analyzed by comparing the experimental value with the theoretical value.The results showed that under the same load,the deflection of BFRP beams was larger than that of reinforced concrete beams,and the mixed reinforced beams were between the two;under the same reinforcement ratio,the bearing capacity of BFRP reinforced concrete beams was lower than that of reinforced concrete beams.Although the BFRP bars had no obvious yield point,the mixed reinforced concrete beams still showed good ductility,and the concrete in the compression zone was crushed and destroyed,which had provided obvious signs before the beam was completely destroyed,and the failure mode was similar to balanced-reinforced beam failure.The sections of BFRP reinforced concrete beams and mixed reinforced concrete beams could basically satisfy the flat section assumption.