高强砂浆粘贴碳纤维网格布加固钢筋混凝土梁正截面受弯性能试验研究

Experimental study on flexural behavior of reinforced concrete beams strengthened with high strength mortar bonded with carbon fiber mesh

通过对5个不同的高强砂浆粘贴碳纤维网格布加固钢筋混凝土梁加固试件及1个未加固试件的对比试验,分析了该加固方法的有效性,测试了各试件抗弯承载力、延性、破坏形态,并提出了该类构件的抗弯承载力计算方法。结果表明:(1)采用高强砂浆粘贴碳纤维网格布加固梁后,梁的抗弯承载力提高了36%~57%;(2)可通过在梁底增加粘贴层数或在梁侧增加粘贴面积提高高强砂浆粘贴碳纤维网格布加固钢筋混凝土梁的抗弯承载力,在梁侧粘贴时,粘结高度不宜超高梁高的1/2;(3)用本文建议公式可计算高强砂浆粘贴碳纤维网格布加固钢筋混凝土梁正截面受弯承载力,公式中的纤维网格布抗拉强度折减系数,对于在梁底粘贴1层粘贴碳纤维网格布的构件可取0.5;对于在梁底粘贴2层粘贴碳纤维网格布的构件可取0.7;对于梁底全部以及梁侧1/2高度处粘贴1层的构件,可取0.45。

Through the comparative test of five reinforced specimens using high-strength mortar bonded carbon fiber mesh sheet to strengthen with different reinforcement methods and one unreinforced specimen,the effectiveness of the reinforcement method is analyzed,the flexural capacity,ductility and failure mode of each specimen are tested,and the flexural capacity of this kind of members is put forward.The results show that:(1)After strengthening the beam with high-strength mortar bonded with carbon fiber mesh,the flexural capacity of the beam is increased by 36%~57%;(2)The flexural capacity of reinforced concrete beams strengthened with high-strength mortar bonded with carbon fiber mesh can be improved by increasing the number of bonding layers at the beam bottom or the bonding area at the beam side.When bonding at the beam side,the bonding height should not exceed 1/2 of the beam height;(3)The formula proposed in this paper can be used to calculate the flexural capacity of reinforced concrete beams strengthened with high-strength mortar bonded with carbon fiber mesh.The reduction coefficient of tensile strength of fiber mesh in the formula can be taken as 0.5 for members bonded with one layer of carbon fiber mesh at the bottom of the beam;0.7 can be taken for components with 2 layers of carbon fiber mesh cloth pasted at the beam bottom;For members pasted with 1 layer at all beam bottom and 1/2 height of beam side,0.45 can be taken.