目的将ECC替代混凝土用于建筑结构以解决因混凝土脆性导致的开裂和耐久性问题.方法提出ECC材料简化拉、压应力-应变关系模型,并通过有限元模拟方法对钢筋增强ECC(R/ECC)柱偏心受压力学性能进行评估.在此基础上,以偏心距为参数,分析了各偏心率下R/ECC偏心受压构件的荷载-变形曲线,得出了承载力N_u-M_u关系曲线.结果笔者提出的模型能够准确地模拟R/ECC构件的承载力及变形行为.在各偏心率下,R/ECC柱的抗弯承载力均要显著大于RC柱,通过应变云图分析可以得知,R/ECC柱受拉侧ECC能够始终提供稳定的抗拉承载力,使得R/ECC柱的极限弯矩要大于RC柱.结论相同条件下,R/ECC柱偏心受压承载力和延性均要明显优于RC构件.
Substitution of concrete with ECC can avoid the cracking and durability problems associated with brittleness of concrete. In this paper, the simplified stress-strain model of ECC under uniaxial tension and compression is proposed and the mechanical behavior of steel reinforced ECC( R/ECC) columns under eccentric compression is evaluated by finite element method. The loaddeformation curves of R/ECC columns with various eccentricities are calculated and the load carrying capacity correlation curves( N_u-M_u) are obtained. It is indicated that the load carrying and deformation responses can be accurately calculated by the proposed model. The flexural strength of R/ECC column is evidently higher than that of RC column. It is observed from the strain contour that the tensile load can be continued provided by ECC during the loading process,making the higher flexural loading capacity of R/ECC column. The simulation results indicate that the R/ECC column shows higher load carrying capacity and ductility than those of RC column under eccentric compressive loading.