内嵌预应力螺旋肋钢丝加固混凝土梁变形特性研究

Research on Deformation of Reinforced Concrete Beam Embedded with Prestressed Helical Rib Steel Wires

针对原有加固方法的不足,提出内嵌预应力螺旋肋钢丝加固混凝土梁加固技术,分析这种加固梁的变形特点,并依据普通钢筋混凝土梁的变形原理和内嵌预应力螺旋肋钢丝加固混凝土梁的特点,推导内嵌预应力螺旋肋钢丝加固梁不同受力阶段的刚度表达式,得到内嵌预应力螺旋肋钢丝加固梁的刚度计算公式。在考虑预加力产生反拱的前提下,计算加固梁不同受力阶段的变形量。对4根内嵌预应力螺旋肋钢丝加固混凝土梁进行了试验验证。结果表明:试验结果与计算结果吻合较好,内嵌预应力螺旋肋钢丝加固混凝土梁能有效延缓裂缝的发展,减小构件变形,提高构件刚度。研究结果为该加固方法在工程实际中的应用提供了理论依据。

Aiming at making up the deficiencies of the conventional concrete reinforcement methods,the reinforcement technology adopting prestressed helical rib steel wires bonded in sawed grooves in the concrete course was presented.The deformation characteristics of so reinforced concrete beams were analyzed.On the basis of such beam deformation characteristics and the deformation principle of ordinary reinforced concrete（RC）beams,the stiffness expressions of the RC beams embedded with prestressed helical rib steel wires in different stressing stages were derived and the stiffness calculation formulas of the RC beams embedded with prestressed helical rib steel wires were set.Under the premise that inverted archs were generated in prestressing,the magnitudes of deformation of the RC beams embedded with prestressed helical rib steel wires in different stressing stages were calculated.Tests were made with four RC beams embedded with prestressed helical rib steel wires.The test results and calculation results show good agreement.The RC beam embedded with prestressed helical rib steel wires can effectively delay development of cracks,reduce member deformation and streng then member stiffness.The research results lay a theoretical basis for application of the new reinforcement method in engineering practice.