考虑区域约束的预应力型钢混凝土梁受弯承载力研究

为研究预应力型钢混凝土框架梁中型钢对混凝土约束作用及对梁承载力的影响,对前期有黏结预应力型钢混凝土框架试验进行研究。研究发现型钢能有效地约束预应力型钢混凝土框架梁中核心混凝土变形,改善受压混凝土破坏时的脆性性能,提高梁的受弯承载力。在此基础上,提出将预应力型钢混凝土框架梁作为压弯构件,参照文献的区域约束混凝土理论,在叠加基础上考虑约束混凝土的额外强度来计算梁的受弯承载力;提出考虑区域约束影响的承载力计算方法,计算结果与试验试件极限状态受弯承载力对比,计算值与试验值比值的平均值为0.98,吻合较好。

Flexural bearing capacity of prestressed steel-reinforced concrete frame beams considering regional constraints

An experimental study on bonded prestressed steel-reinforced concrete frames at an early stage was conducted to investigate the constraint imposed by steel in the prestressed steel-reinforced concrete beam to concrete and its impact on the carrying capacity of the frame beam. Test results show that steel can effectively restrain concrete deformation in the core area, improve the brittleness of concrete under pressure when it is destroyed, and enhance the flexural bearing capacity of the beam. With regard to prestressed steel-reinforced concrete frame beams in bending, and with reference to the theory of confined concrete as described in the literature, a bearing capacity calculation method for prestressed steel-reinforced concrete frame beams considering regional constraints is proposed based on the superposition principle. The calculated results of the flexural bearing capacity of prestressed steel-reinforced concrete beams are compared with the test results in the limit state. The average ratio of the calculated results to the test results is 0. 98, demonstrating agreement between them.