钢板-混凝土组合加固混凝土T梁的抗弯性能试验

设计了4根钢板-混凝土组合加固混凝土T梁进行抗弯承载力试验, 试件的主要设计参数包括损伤程度和植筋间距。采用荷载传感器、位移计和应变计, 分别测量了加载过程中试验梁的荷载、挠度、应变、裂缝的产生和发展、新老混凝土界面与钢板-加固混凝土界面的纵向滑移, 采用有限元软件ANSYS分析了试件的受力性能, 采用塑性方法研究了试件的极限抗弯承载力, 并对比了模型试验、数值模拟与理论分析结果。分析结果表明: 钢板-混凝土组合加固可使混凝土T梁极限抗弯承载力提高约2倍, 植筋间距与原梁弯曲损伤程度对组合加固T梁的极限抗弯承载力影响约为4%, 植筋间距越大, 新老混凝土界面纵向相对滑移越大, 极限抗弯承载力的数值计算值和理论计算值与试验值最大相对差值为9%, 因此, 模型试验、数值模拟与理论计算结果均表明钢板-混凝土组合加固可显著提高混凝土T梁的极限抗弯承载力。

Flexural behavior experiment of reinforced concrete T-beams with steel plate-concrete composite strengthening

The flexural behaviors and failure modes of four reinforced concrete T-beams with steel plate-concrete composite strengthening were investigated. The major design parameters included damage level and bar-planted space. The loads, deflections, strains, cracks of test T-beams, the slippages between new and existing concretes, and the slippages between steel plates and new concretes were respectively measured by using load, deformation sensors and strain gauges. The ultimate bending capacities of test T-beams were simulated by using finite element software ANSYS, and were analyzed by using plastic method. The simulation values, theoretical calculation values and test values were compared. Comparison result shows that the ultimate bending capacities of the T-beams increase by two times. The influence degrees of damage levels and bar-planted spaces on the ultimate bending capacities are about 4%. The longitudinal slippages between the original and new concretes increase with the increments of bar-planted spaces. The maximal absolute differences among the simulation values, theoretical calculation values and test values are 9%, so steel plate-concrete composite strengthening method is feasible.