CFS/GFS层间混杂加固纤维混凝土梁抗弯试验研究

Experimental Investigation into Flexural Behavior of Fiber-Modified Concrete Beam Strengthened with CFS/GFS

对采用杜拉纤维和钢纤维混杂改性的混凝土梁外贴碳纤维布和玻璃纤维布(CFS/GFS)进行混杂加固抗弯试验,对构件的开裂及发展情况以及构件加固后刚度的变化进行了对比分析研究.试验结果表明,掺入杜拉纤维和钢纤维,可以延缓混凝土构件微裂缝的出现,控制裂纹扩展,提高混凝土材料的强度,这种混杂纤维混凝土梁在试验过程中表现出比单一纤维混凝土梁更为优良的材料性能.采用不同形式的纤维布加固混凝土梁得到的加固效果有较大的不同,按试验方案采用CFS/GFS层间混杂加固纤维混凝土梁是一种有效的加固方法,在保证提高承载力的前提下,既提高了纤维混凝土构件的延性,又可降低加固成本.

Test analyses are carried out to reveal the flexural behaviours of polypropylene fiber and steel fiber-modified concrete beams strengthened with mixed carbon fiber sheets （CFS） and glass fiber sheets （GFS）. The crack and its development, as well as the rigidity variation after the strengthening are then analyzed. Tested results show that （ 1 ） polypropylene fibers and steel fibers can postpone the appearance of microcracks in concrete, control the development of cracks and improve the concrete strength; （2） the concrete beam modified with hybrid fibers are superior to that modified with single fiber; （3） the strengthening effect greatly depends on the strengthened fiber sheets; and （4） the concrete beams strengthened with CFS/GFS is effective and is helpful to improve the toughness, reduce the cost and enhance the load bearing capacity of the beam.