圆钢管钢筋再生混凝土短柱轴压承载力

针对再生混凝土相对普通混凝土延性较差、承载力较低的特点,利用钢管和钢筋笼对再生混凝土的约束作用,将钢筋再生混凝土灌入圆钢管中形成圆钢管钢筋再生混凝土短柱进行研究。基于极限分析法、套箍理论以及双剪统一强度理论,考虑钢管和钢筋笼的双重约束效应,提出了一套包含钢管径厚比、约束效应系数、含钢率以及再生粗骨料取代率等影响因素的圆钢管钢筋再生混凝土短柱轴压承载力计算方法。在理论推导的基础上,考虑短柱的非线性、钢管与再生混凝土的滑移影响,采用ABAQUS有限元软件对圆钢管钢筋再生混凝土短柱进行建模分析; 将理论公式值、有限元仿真结果以及相关文献试验数据进行对比,验证公式的有效性与适用性。结果表明:加了钢筋笼的圆钢管钢筋再生混凝土比圆钢管再生混凝土短柱轴压承载力提高10%左右,研究结论可以为实际工程的应用提供理论基础。

Axial Compression Carrying Capacity of Reinforced Recycled Aggregate Concrete-filled Circular Steel Tubular Stub Columns

In view of the poor ductility and low bearing capacity of recycled aggregate concrete(RAC)compared with ordinary concrete, using the restraint effect of steel pipe and reinforcement cage on RAC, the reinforced recycled concrete was poured into the circular steel tube to form reinforced recycled aggregate concrete-filled circular steel tubular(RRACFCST)stub columns. Based on the limit analysis method, hoop theory and twin shear unified strength theory, the double restraint effect of steel pipe and reinforcement cage were considered, and the calculation methods for axial compression bearing capacity of circular steel tube reinforced recycled concrete stub columns including steel tube diameter thickness ratio, restraint effect coefficient, steel ratio and replacement rate of recycled coarse aggregate were proposed. On the basis of theoretical derivation, the nonlinear of short column and the influence of slip between steel tube and recycled concrete was considered, the finite element software ABAQUS was used to model and analyze the circular steel tube reinforced recycled concrete stub column. The theoretical formula value, finite element simulation results and relevant literature test data were compared to verify the validity and applicability of the formula. The results show that the axial compression bearing capacity of recycled concrete filled circular steel tubular stub columns with reinforcement cage is about 10% higher than that of recycled concrete filled circular steel tubular stub columns. The research conclusion can provide a theoretical basis for practical engineering application.