【作者】 欧阳利军；

【导师】 赵艳林； 吕海波；

【作者基本信息】 广西大学 ， 结构工程， 2007， 硕士

【摘要】 钢筋与混凝土之间的良好的粘结是保证钢筋与混凝土共同受力与变形的基本前提。锈蚀导致的钢筋与混凝土粘结性能退化问题是混凝土结构耐久性降低的重要的因素之一。声发射检测技术是金属及复合材料内部缺陷监测的有力手段，该技术在土木工程领域有着广泛的应用。本文开展了不同腐蚀程度的混凝土试件的中心拔出试验，并结合声发射无损检测技术，对钢筋与混凝土粘结破坏过程进行监测，从微细观的角度解释和评定了拔出试件的粘结性能退化过程，得到的主要研究成果如下：一、通过铅笔折断试验和模拟试验环境加载，确定了符合试验材料的检测参数，比如，门槛、时间参数、波速、衰减等，为混凝土声发射检测参数选取提供了可靠的依据。二、通过混凝土中心拔出试验，对不同锈蚀程度的试件的粘结性能进行研究，得出了拔出试件在不同锈蚀阶段的平均粘结力-滑移量关系、粘结强度-钢筋锈蚀率关系、滑移量-钢筋锈蚀率关系。三、论文在传统的中心拔出试验本构参量分析的基础上，引入了声发射参量。通过声发射参数分析，反映了粘结试件随应力水平变化的声发射特性，并在此基础上，通过分析声发射参数关联图、信号幅度、频率、上升时间、持续时间等，对试件在受载过程中内部缺陷类型和强度进行识别。并借助声发射源定位分析技术，确定了试件在受载过程内部缺陷位置及发展趋势。最后验证了混凝土粘结破坏的声发射过程的凯塞现象。更多还原

【Abstract】 Favorable bond strength supplies insurance to resist loads and deformations for concrete combined with steel bar in reinforced concrete. Bond deterioration, caused by corroded rebar, is one of the main reasons for the decrease of durability in reinforced concrete construction .Acoustic emission(AE) technique, a useful method for the investigation of damages in metal and composite materials, is extensively applied to a variety fields in civil engineering. This paper carries out pull-out tests on different degrees of corroded specimens ,and uses the AE technique to detect damaging specimens during loading, and applies micro-analysis method to explain and evaluate the bond deterioration process of the specimens . Several results has been gained as follow:1、Through lead-breaking and stimulant loading tests, reasonable detecting parameters, such as threshold ,time parameters, velocity of signal, attenuation are gained .These tests also supply some important and available ways to chose detecting parameters in concrete AE detection.2、The bond strength of different degrees of corroded specimens are studied through pull-out tests. The pull-out tests revealed the following varied degrees of bond strength in corroded specimens: the law of average bond resistance coinciding with the slipping quantity of rebar ;the law of bond strength coinciding with corrosion degrees ,and the law of slipping quantity at the ultimate bond strength coinciding with corrosion degrees as studied in post-corroding , post-cracking and cracking stage.3、Based on the traditional analysis of basic issues in pull-out tests, this paper also considers AE parameters .Through parameter analysis, characters of AE parameters coinciding with the changing of stress level is studied. In addition, inner damages and its intensities in samples were identified during the loading process through correlating graph ,risetime, duration, amplitude and frequency analyses. By means of AE source location technique ,the position of cracks and their progress tendency was ascertained. At last, the Kaiser effect in concrete material during bond destruction was proven.更多还原