模拟严重锈蚀钢筋的混凝土梁试验与钢筋应力分析

TEST STUDY AND ANALYSIS ON STEEL STRESS OF SIMULATED HEAVILY CORRODED R.C.BEAMS

锈蚀引起的粘结性能退化导致钢筋与混凝土之间的协同工作性能降低,跨中的钢筋应变较混凝土应变滞后,当构件严重锈蚀时,钢筋与混凝土间的粘结力基本丧失,可能在钢筋达到屈服应变前受压区混凝土先行压坏,形成粘结失效超筋梁。通过严重锈蚀钢筋混凝土梁的模拟试验和有限元分析,研究在完全无粘结的极限情况下影响钢筋应力水平的因素及其影响规律,并建立了无粘结状态混凝土梁受拉钢筋应力与配筋指标的关系,为严重锈蚀混凝土构件的承载力计算提供依据,同时也为研究一般锈蚀钢筋混凝土构件的性能退化机理与承载力计算方法奠定基础。

Due to deterioration of bond strength caused by corrosion, cooperative working capacity between steel bar and concrete is degrading, which makes steel strain lag behind concrete tensile strain. When the member corroded heavily, bond stress between steel bar and concrete is almost lost, and concrete in the compression zone may be failure before tensile steel bar arrives its yielding strain, which may make the member form a surplus reinforcement beam due to bond failure test. Simulation and finite element analysis on simulated corroded unbonded R.C. beams are made to investigate factors affecting the level of steel stress and its affecting rules in the limit states without bond. The relation between steel stress and reinforcement index of unbonded R.C. beams is established, which can be used to evaluate the bearing capacity of heavily corroded beams, and which can also be helpful to study the degrading mechanism and calculating method on bearing capacity for ordinary corroded R.C. beams.