UHPC加固钢筋混凝土梁的抗弯性能研究

Study on bending performance of reinforced concrete beams reinforced by UHPC

为研究加固后钢筋混凝土梁的抗弯性能,采用UHPC对钢筋混凝土梁进行局部加固,并把加固厚度作为研究变量。利用四点弯曲试验对加固后梁的抗弯强度进行了研究,得到了跨中荷载-位移曲线、跨中应变沿梁高分布曲线、裂缝发展变化,并与未加固的钢筋混凝土梁进行了对比分析。研究结果表明,在受拉区和受压区采用UHPC加固钢筋混凝土梁,其极限抗弯强度随UHPC加固厚度的增加而增加。在此基础上,利用MSC/Marc有限元进行模拟,证明了UHPC提高了梁的刚度,延缓了局部裂缝的形成,从而提高了加固梁的抗弯承载力和耐久性。

In order to study the flexural behavior of reinforced concrete beams after reinforcement,UHPC is adopted for local reinforcement of reinforced concrete beams,and the reinforcement thickness is taken as the research variable.The four points bending test is used to study the bending strength of reinforced beams,and the load-displacement curve,the strain distribution curve along the beam height,and the crack development and change obtained.The results show that the ultimate flexural strength of reinforced concrete beams strengthened by UHPC increases with the increase of the strengthened thickness of UHPC.On this basis,the finite element simulation with MSC/Marc shows that UHPC improves the stiffness of the beam,delays the formation of local cracks,and improves the resistance and durability of the strengthened beam.