论文部分内容阅读
通过2根未受火钢筋混凝土梁、2根受火后钢筋混凝土梁和4根受火后CFRP布加固钢筋混凝土梁的静载试验,研究了剪跨比、CFRP布加固量和楼板翼缘对受火后钢筋混凝土梁受剪加固效果的影响。采用自编有限元程序分析受火损伤的混凝土梁截面通过等截面修复后截面混凝土抗拉强度的平均折减系数,提出受火后CFRP布加固钢筋混凝土梁受剪承载力的实用计算方法。研究结果表明:加固梁破坏时,外包的CFRP布发生拉断破坏,“U形包裹加压条”的CFRP布发生剥离破坏;受火后外包CFRP布加固混凝土矩形梁的受剪承载力相比未受火钢筋混凝土梁提高了5.3%~16.6%;受火后“U形包裹加压条”方式加固混凝土T形梁的受剪承载力相比对应未受火矩形梁提高了34.0%。提出的受火后CFRP布加固钢筋混凝土梁受剪承载力的计算式具备一定的安全保证率,可用于该类构件受火后的受剪加固计算。
The static load test of two uncoated reinforced concrete beams, two reinforced concrete beams subjected to fire and four reinforced CFRP beams subjected to fire were carried out. The effects of shear span ratio, CFRP reinforcement and floor flange pairs Effect of Shear Reinforcing Effect of Reinforced Concrete Beams Upon Fire. The finite element method is used to analyze the practical calculation method of the shear capacity of reinforced concrete beams strengthened with CFRP sheets after being damaged by fire through the average reduction coefficient of the tensile strength of the concrete sections after being repaired by the same cross section. The results show that when CFRP sheet is damaged, the CFRP cloth is pulled off and broken, and the “CFRP sheet” with “U-shaped wrap” is peeled and damaged. The shear strength of CFRP-reinforced concrete rectangular beam after fire Compared with un-fire reinforced concrete beams increased by 5.3% to 16.6%; by the fire after the “U-shaped package pressure strip” reinforced concrete T-beam shear strength compared with the corresponding unirradiated fire rectangular beam increased 34.0%. The formula for calculating the shear capacity of RC beams strengthened by CFRP after fire is proposed to have a certain safety guarantee rate and can be used to calculate the shear reinforcement of such members after fire.