CFRP布加固箱型混凝土梁受弯试验研究

Experimental study on flexural performance of box type reinforced concrete beams strengthened with CFRP

针对箱型钢筋混凝土梁进行了CFRP布加固试验研究,考察混凝土强度、配筋率、U形箍间距、加固量等因素对箱型梁在抗弯性能和力学行为等方面的影响。试验制作了8根试验梁,将加固后的箱型梁的承载力、延性和刚度的性能进行了对比分析,综合评价各因素的加固效果,并通过比较材料应变随荷载变化曲线分析CFRP布加固对钢筋受力影响。CFRP布加固箱型混凝土梁能够较好地改善其受弯性能,有效抑制裂缝的发展和延长裂缝发生时间,相比标准梁,CFRP布加固箱型混凝土梁裂缝数量明显增多。CFRP布加固后可以有效抑制裂缝的发展,能够充分发挥材料性能,明显提高梁的刚度,有效提高梁的极限荷载。混凝土开裂前,加固梁钢筋和加固材料应变相差不大,共同受力;钢筋屈服后,CFRP布应变增加的速度明显加快,说明CFRP布承担着大部分荷载,充分发挥了其抗拉强度高的优点。

The box type reinforced concrete beams were studied on CFRP strengthened experimental,to investigate the strength of concrete,reinforcement ratio,U-shaped hoop spacing,a mount of reinforcement factors on the box beam impact in terms of flexural performance and mechanical behavior.Test produced eight beams and carrying capacity, ductility and stiffness properties of reinforced box beam were comparative analysis.Comprehensive evaluation of various factors reinforcing effect and by comparison with the load curve of the material strain analysis of reinforced CFRP reinforcement force.CFRP reinforced concrete box beam can better improve the flexural properties, effectively inhibit the development of cracks and crack extension of time of occurrence, compared to standard beam, CFRP reinforced concrete box beam significantly increased the number of cracks.CFRP reinforcement can effectively inhibit the development of cracks,can give fnll play to the material properties, significantly increase the stiffness of the beam,the beam effectively improve the ultimate load.Before concrete cracking,reinforcement steel beams and reinforcement material strain are or less,and can common force. After steel yielding, CFRP strain increases significantly faster, indicating CFRP bear most of the load at this time, give full play to its high tensile strength advantage.