钢套管-钢纤维砂浆加固预损柱轴压性能研究

Study on axial compression performance of predamaged columnsreinforced with steel casing and steel fiber mortar

为改善钢套管加固法的力学性能,引入新型加固材料钢纤维水泥砂浆,提出了钢套管-钢纤维水泥砂浆加固预损RC柱的新型组合结构形式。基于试验研究,利用ABAQUS建立了相应的加固柱计算模型并验证其合理性,并对影响此类加固柱轴压力学性能的关键因素进行了非线性参数分析。结果表明:加固柱极限承载力随钢套管厚度、钢材强度和钢纤维水泥砂浆强度的增大而提高,变化钢套管厚度对加固柱延性影响更大,而增大钢纤维水泥砂浆强度会对延性产生不利影响;采用套箍加载方式能够获得更高的承载力提升效果与变形性能;相同损伤程度情况下,变化内柱混凝土强度对加固柱性能影响很小;根据叠加原理推导了此类加固柱的轴压承载力计算公式,公式计算结果与有限元模拟结果吻合良好。

In order to improve the mechanical properties of steel casing reinforcement method,a new type of reinforced material steel fiber cement mortar is introduced,and a new type of composite structure of steel casing reinforced with steel fiber cement mortar(SFRC)is proposed.Based on the experimental research,the corresponding calculation model of the reinforced column was established by using ABAQUS and its rationality was verified,and the nonlinear parameter analysis of the key factors affecting the axial pressure performance of such reinforced column was carried out.The results show that the ultimate bearing capacity of reinforced columns increases with the increase of steel casing thickness,steel strength and steel fiber cement mortar strength,and the change of steel casing thickness has a greater impact on the ductility of reinforced columns,while the increase of steel fiber cement mortar strength has a negative impact on the ductility.The hooper loading method can obtain higher lifting effect of bearing capacity and deformation performance.With the same damage degree,the concrete strength of the inner column has little influence on the performance of the reinforced column.Based on the superposition principle,the calculation formula of axial bearing capacity of this kind of reinforced column is derived,and the calculation results are in good agreement with the finite element simulation results.