【作者】 王波；

【导师】 袁迎曙；

【作者基本信息】 中国矿业大学 ， 结构工程， 2012， 博士

【摘要】 氯盐侵蚀环境下钢筋混凝土结构性能退化是耐久性研究中最为突出和重要的一个组成部分。氯离子通过对材料的侵蚀，使得钢筋混凝土基本构件的静力以及动力性能发生改变，进而影响整个结构的力学性能。本文结合人工气候环境下的加速试验研究，全面揭示氯盐侵蚀造成的钢筋混凝土结构耐久性退化的规律，并结合理论分析建立了相应的耐久性退化模型。通过对人工气候环境加速氯离子侵蚀构件内的锈蚀钢筋表面锈蚀形态的详细调查和研究，对钢筋表面的坑蚀情况进行了基于概率的分析和统计，得到了蚀坑的形状以及三维尺寸的演变规律以及与锈蚀率相关的分布模型；基于试验研究，建立了锈蚀钢筋屈服强度的判别方法（YPPCR法），基于此开展了蚀坑对钢筋名义屈服强度退化的有限元分析和概率分析，得到了蚀坑三维尺寸对强度退化的影响规律和相应的计算模型，建立了与三维尺寸相关的单坑名义屈服强度退化模型，结合蚀坑测量结果，对名义屈服强度的概率分布进行了分析，建立了与锈蚀率相关的名义屈服强度退化模型以及标准强度退化模型。基于全梁粘结试验以及理论分析，建立了锈蚀梁锚固区与位置相关的局部粘结滑移本构模型，以及相应的特征值退化模型，建立了梁端锚固区的粘结分布预计方法和极限锚固力预计方法；基于试验和理论分析，建立了考虑压区钢筋锈蚀以及粘结性能退化的梁抗弯承载力模型，以及抗弯梁从正截面破坏向锚固破坏转变的界限模型，以及锚固破坏时的承载力计算模型。基于锈蚀梁的抗剪性能试验以及临界斜裂缝开展规律试验，得到了梁抗剪承载力退化的规律，结合理论研究，建立了基于极限平衡理论的锈蚀钢筋混凝土梁的抗剪性能退化模型，基于斜压场理论和粘结理论，建立了临界斜裂缝倾角退化模型，进而对梁端锚固性能的退化进行预计，建立了从抗剪破坏到锚固破坏的破坏形态转变模型。对不同锈蚀程度的锈蚀压弯构件进行了低周反复加载试验，得到了锈蚀压弯构件耗能能力退化和恢复力退化的规律；结合理论分析以及试验研究，选择合理的恢复力模型以及相应的滞回规则，建立了综合考虑锈蚀钢筋力学性能退化，混凝土锈胀开裂造成的截面损失，轴压比，以及粘结性能退化影响的压弯构件恢复力退化模型，为框架结构的力学性能退化预计奠定了基础。对不同锈蚀程度的框架边节点构件进行了低周反复加载试验，并考虑了轴压比的影响。得到了节点梁端力学性能退化的规律；结合理论分析以及试验研究，建立了综合考虑钢筋锈蚀后的力学性能退化，混凝土锈胀开裂后的损伤，以及粘结性能退化影响的压弯构件恢复力退化模型以及节点梁端恢复力退化模型。与压弯构件一起为框架结构基于构件的非线性分析奠定基础。对锈蚀前后的单层单跨框架进行低周反复加载试验，对锈蚀后框架结构的抗力以及破坏过程进行了研究和分析，结合基本构件静力和动力力学性能退化的研究，结合非线性分析方法，对锈蚀框架结构进行拟低周反复加载的仿真分析和验证，对锈蚀框架结构的耐久性退化的规律和机理进行了初步的研究。更多还原

【Abstract】 Research on the mechanical performance degradation of RC structures corroded by chlorideis one of the most important parts in the durability studies. The cloride ions erode rebars andconcrete, debase the statical and dynamical mechanical properties of RC members, and finallyreduce the mechanical performance of RC structures. Accelerated corrosion experiments inartificial climate environment of RC members and joints were finished to reveal the objectivemechanical capability degradation laws of RC structures corroded by chloride, and the relateddurability retrogression model were established.Based on the accelerated corrosion experiments in artificial climate environment anddetailed investigations on the corriosion states and corriosion pits on the surface of rebars incorroded RC members, probabilistical analysis and statistics of pit shapes and sizes wereproceeded, the occurrence probability models of each kind shape were established, as well as themechanism of growth and evolvement of corrosion pits. Tensile tests of corroded rebars wereconducted with statical loads. The judgement method of nominal corroded steel bar yeild pointwas built according to the above test results.Which was simplified as “YPPCR”menthod. Thenfinite element analysis were carried out to analyze and establish the pitting effect on nominalyeilding strength. With the help of the above effort, Probabilistical nominal yeilding strengthdegradation model was bulit.Retrogression of bond behaviour inside of beams were studied through experiments andtheorical analyze. The local bond-slip relation were bulit based on the comparison research ofpullout test and beam test. The corresponding local bond-slip retrogression were built.According to the experimental studies on statical loading of corroded RC beam, the effectsof steel corrosion, concrete cover cracking and bond retrogression on degradation of corrodedRC beam were investigated seperately. Then taking these effects into the strain coordinationrelation along the height of beam section at the critical transverse crack, where force andmoment equilibrium could be united to decide the concealed and real strain relation of concreteand rebars. With the help of accurater bond-slip retrogression model in the beam established inthe previous chapter of this dissertation, the accurater bending capacity degradation model wasbuilt. According to the phenomenon of bond failure at the bending-shear area with severercorrosion crack and corrosion degree than other area, the judgement method of failure modetransformation of bending beams were buit. It was found that, the balance between ultimateanchoring force of anchorage area and yeilding force of reinforcement in tension was not theonly critical state.Shear capacity degradation experiments of corroded RC beams were conducted to investigate the shear capacity retrogression laws with enhanced corrosion degree gradually.Influence of different stirrup space，shear span rate and corrosion degree were taken into account.It was found that, as the corrosion degree increased, the shear capacity degraded. Beam withsmaller shear span rate or smallerstirrup space had higher shear capacity, but with the samecorrosion rate, beam with larger stirrup span rate had severer shear capacity degradation. effectof stirrup corrosion had unvisible influence on shear capacity of beams with small shear span. Atthe same time, the effect of corrosion on critical inclined crack was investigated, the angle ofcritical inclined crack was tend to reduce as the corrosion degree increase, with significantdiscreteness. When the final failure mode was bond failue, the critical inclined crack was veryclosed to supports.Based on the experimental results and theorical analysis, the shear capacity dagradationmodel was built. The critical inclined crack angle degeneration model was built. Taking theinduced critical inclined crack angle into the equilibrium, the anchorage lenghth predictionmodel was built.Based on the anaylsis of critical failure state and the limit equilibriumtheory,The failue mode transformation model was built.Cyclic loading tests of corroded RC columns with constant axial force and RC joints wasperformed. They had similar degradation laws. The yeild capacity and ulitmate capacity debasedas the corrosion induced. The yeild diplacement had slight change, but the ultimate debasedclearly. Because of the corroded element had no significant yeild point in the load-displacementcurve, the yeild strengh was calculated by equal energe method, the test result of yeild strengthhad difference the actual one. The resilience curve showed that, as corrosion induced, the energydissipation capacity of columns and joints decreased gradually.Based on the strain equilibrium，force and moment equilibrium on the cross section, withconsideration of steel corrosion, concrete damage，bond degradation， the resilience capacitydegradation model was built separetely， with corresponding characteristic parametersdegradation model.Experimental study on seismic resistance performance degradation of RC Frame Corrodedby Cloride were carrided out. The numerical simulated cycle loaded analysis were proceededwith IDAC-2D and the mechanical degradation model of basic elements. The numerical analysismethod was proved by the test result.更多还原