【作者】 郑明；

【导师】 金伟良； 孙家瑛；

【作者基本信息】 浙江大学 ， 建筑与土木工程（专业学位）， 2015， 硕士

【摘要】 混凝土中钢筋锈蚀是影响其耐久性的主要因素之一,而氯离子侵蚀又是造成钢筋锈蚀的重要诱因。弯拉荷载是混凝土梁式结构所承受的最常见的荷载形式,混凝土在受力时的渗透性与未受力时会有很大的不同。大量处在沿海地区及北方除冰盐环境中的混凝土结构,其耐久性问题主要是由应力、碳化和氯盐共同作用所引起,而目前国内外对于多因素及其耦合作用下氯离子在混凝土中传输的研究尚在起步阶段。因此,本文采用自制的弯拉加载装置,研究了混凝土在荷载-碳化及其耦合作用下氯离子的传输问题。首先,本文对试验原材料的物理化学特性进行研究,确定出C30混凝土的试验配合比；再进行混凝土快速碳化试验,获得不同碳化龄期的混凝土试件,阐述了碳化时间对碳化深度的影响,并结合ASTM C1202电通量法评价其渗透性,研究了碳化作用对氯离子渗透性能的影响,利用SEM电镜扫描对碳化和氯离子作用下的混凝土微观形貌进行了分析。其次,根据定制的模具,使用自制的弯拉加载装置,获得不同弯拉加载比下的混凝土试件,再分别结合快速碳化和电通量法,研究了混凝土在受荷状态下的抗碳化能力和抗氯离子渗透性能,利用SEM电镜扫描对荷载作用下的混凝土微观形貌进行了分析。最后,对混凝土试件施加弯拉荷载,再进行快速碳化试验,运用电通量法测定通过混凝土试件的电量Q,揭示了在荷载与碳化耦合作用下混凝土氯离子渗透规律,并利用SEM电镜扫描对荷载与碳化耦合作用下的混凝土微观形貌进行了初步分析。更多还原

【Abstract】 Corrosion of reinforcement is one of the main factors that influence the durability of concrete.Chloride ion penetration is an important cause of reinforcement corrosion. Flexural-tensile load is the most common load form of concrete beams,concrete permeability under flexural-tensile load will have a big difference with non-stress concrete. In coastal areas and northern deicing salt environment,carbonation, chloride ion penetration and loads have extremely important effects on concrete durability. At present, research on chloride ion transmission in concrete under multiple factors and their coupling effects is still at an early stage.Chloride ion transport problems are studied on this paper and concrete samples are under loads-carbonation and its coupling effect by a novel flexural loading device.Firstly, this paper studies physical properties and chemical compositions of the test materials, and confirms the test mix proportion of C30concrete.And it expounds the effects of carbonization time on the depth of carbonation and carbonization on concrete chloride ion permeability, as concrete specimens with different carbonation ages are obtained by rapid carbonization test, and they are tested with ASTM C1202method;and it analyses the micro-structure of concrete under carbonation or chloride ion penetration by SEM.Secondly, concrete specimens with different flexural-tensile load ratio are obtained by a custom mold and a novel flexural loading device. And they are tested with ASTM C1202method and carbonization test. It studies the effects on chloride ion penetration resistance and carbonization resistance of concrete under load,and it analyses the micro-structure of concrete under load by SEM.Finally, concrete specimens are made with different flexural-tensile load ratio, then they are tested by rapid carbonization. And electric quantity Q through the concrete specimens are measured with ASTM C1202method.It reveals the chloride ion penetration law of concrete under carbonation coupled with load,and it preliminarily analyses the micro-structure of concrete under carbonation coupled with load by SEM.更多还原