锈蚀率对钢筋混凝土梁黏结滑移性能影响的试验研究

Experimental study on the influence of corrosion rate on bond-slip behavior of reinforced concrete beams

建立了锈蚀钢筋混凝土梁中钢筋与混凝土之间黏结滑移数值分析模型,设计制作了14根不同剪跨比与锈蚀率的钢筋混凝土梁,采用ANSYS有限元软件建立了锈蚀钢筋混凝土梁的三维有限元模型,对14根钢筋混凝土梁开展极限承载力试验,从锈蚀钢筋混凝土梁的荷载-跨中挠度曲线、极限承载力以及钢筋与混凝土之间黏结力3个方面开展对比分析研究,结果表明锈蚀钢筋混凝土梁的荷载-跨中挠度曲线均可大致分为弹性和塑性两个阶段,随着锈蚀率变大,弹性阶段与塑性阶段的分界逐渐不明显。锈蚀钢筋与混凝土之间的黏结力随着距离跨中截面距离的增大变大,且最大黏结力位置出现于加载点附近,同级荷载下,最大黏结力随着锈蚀率的增加而减小。锈蚀钢筋混凝土梁极限承载力随着锈蚀率和剪跨比的增加而变小,当剪跨比为3.0时,平均每升高1%锈蚀率,极限承载力试验值降低1.002 k N,当剪跨比为2.4时,平均每升高1%锈蚀率,极限承载力试验值降低1.849 k N。

Numerical analysis model of the bond-slip relationship between reinforcement and concrete were established in corroded reinforced concrete beams.14 reinforced concrete beams with different shear span ratios and corrosion rates were designed and made,three-dimensional finite element model of the corroded reinforced concrete beams were established by ANSYS finite element software,the ultimate bearing capacity experiment of 14 corroded reinforced concrete beams were carried out,the experimental results were compared from three aspects,load-deflection curves,ultimate bearing capacity and cohesive force between reinforcement and concrete.The results show that the load deflection curve of corroded reinforced concrete beams can be divided into elasticity stage and plasticity stage,with the increase of corrosion rate,the boundary between elastic stage and plastic stage got less obvious.The bond force between corroded reinforcement and concrete get bigger with the increase of distance from middle cross section,the maximum bond force appeared near loading point,and the maximum bond force decreased with the increase of corrosion rate under the same load level.The ultimate bearing capacity of corroded reinforced concrete beams decreased with the increase of corrosion rate and shear span ratio,when shear span ratio was 3.0,the ultimate bearing capacity decreased by 1.002kN with an average increase of 1%corrosion rate.When shear span ratio was 2.4,the ultimate bearing capacity decreased by 1.849 kN with an average increase of 1%corrosion rate.