受栓钉强度控制的钢板-混凝土界面黏结滑移性能试验与本构模型

Experiment and constitutive modeling of bond-slip behavior of steel plate-concrete interface with strength controlled by stud shear connectors

以预应力型钢-混凝土界面为研究对象,旨在建立钢板-混凝土栓钉连接界面黏结滑移的本构关系。研究以混凝土强度、栓钉数量及法向压应力为变量,采用正交试验法对18个钢板-混凝土界面试件进行剪切试验。试验界面取为原型界面足够小的单元,使其能代表该单元内一点处的性能,从而探讨一点处的黏结滑移性能,并得到一点处的黏结应力-滑移关系曲线。结果表明：试验后期均发生栓钉剪断造成黏结应力骤降的破坏。混凝土强度和法向压应力的增加对界面的屈服、峰值和残余黏结应力均有提高作用;栓钉含量对界面的屈服及残余黏结应力影响不大,但可提高界面的峰值黏结应力,还可增大峰值黏结应力点的滑移及残余段初始滑移,提高延性。基于试验结果分别建立了无栓钉、含单栓钉和含双栓钉的钢板-混凝土界面黏结滑移本构模型,统计回归了模型中特征点的应力及滑移等参数的算式。所提模型与试验结果吻合良好,达到了在黏结滑移本构关系中考虑栓钉影响的目的。

Taking the steel-concrete interface in prestressed steel reinforced concrete as the background, this paper aims at establishing a bond-slip constitutive relation for the interface including the effect of studs. Therefore, orthogonal bond-slip tests of eighteen steel-concrete interface specimens were conducted with concrete strength, amount of studs, and normal compressive stress as the variables. The tested interface was taken as an element of the prototype interface small enough to represent its behavior as a point in the element region, so that in this sense the bond-slip behavior at a point can be investigated. The bond stress-slip curves were obtained. Results show that, in the later stage of the test, all the studs are sheared off the steel plates causing a sudden drop in bond stress. The increase in concrete strength and normal compressive stress can both improve the yielding, peak and residual bond stresses of the interface. Although the studs show little effects on yielding and residual bond stresses, they can help increase the peak bond stress, the peak point slip, and the slip at the onset of the residual stage, making the interface failure more ductile. Based on the test results, bond-slip constitutive models for steel-concrete interfaces without studs, with one stud, and with two studs were proposed in which the formulas for characteristic bond stresses and characteristic slip values were determined by statistical regression. The proposed model is in good agreement with the experimental dada and therefore can be used to simulate the bond-slip behavior between steel and concrete including the effect of studs.