【作者】 谭智军；

【导师】 巴恒静；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2008， 硕士

【摘要】 随着海洋混凝土工程的日益增多,海洋环境下的混凝土耐久性受到了极大的挑战。在众多影响海洋混凝土耐久性的因素当中,氯离子导致的钢筋锈蚀是最为严重的因素之一。最近发现在海洋潮间带的混凝土表面上附着许多海洋生物,形成一层很厚的膜状结构,即本文所称的海洋生物膜,这些生物膜的成分中包含藤壶、牡蛎的外壳以及微生物及其有机代谢产物,同时发现附着之生物膜与混凝土耐久性之间有一定的关系,本文基于这个现象,对海洋生物膜对海洋混凝土抗氯离子渗透性的影响进行了系列的研究。所开展的工作主要有:(1)对青岛某海港旁防波堤上的混凝土工程进行钻芯取样,分析附着在混凝土表面上的生物膜组成成分;(2)对钻芯混凝土进行氯离子加速渗透试验,分析生物膜中的各种成分以及生物膜失去活性前后对潮间带混凝土抗氯离子渗透性的影响;(3)测定混凝土中氯离子含量沿深度的分布规律,分析附着于混凝土表面上的生物膜在混凝土长期服役过程中对混凝土抗氯离子渗透性的作用;(4)通过微观手段观察钻芯混凝土上生物膜的微观结构和分析生物膜的成分,从微观的角度分析生物膜对混凝土抗氯离子渗透性的影响。通过以上的研究工作,得出以下研究结果:潮间带混凝土表面海洋生物膜成分主要为牡蛎、藤壶外壳、微生物及其有机代谢产物等;海洋生物膜中的牡蛎外壳和藤壶夹杂附着在潮间带上层混凝土时对混凝土抗氯离子渗透影响最大,能减少渗入混凝土内部的氯离子含量;从整个混凝土服役过程来看,潮间带上层混凝土的实际氯离子含量高于下层,说明潮间带上层混凝土表面上的生物膜保护效果不够理想;研究表明生物膜具有活性时对混凝土抗氯离子渗透影响优于失去活性后,可能与微生物中的嗜盐菌吸收Cl?、生物膜干燥后部分脱落等因素有关;混凝土的碳化检测和微生物种属鉴别结果表明生物膜中不存在硫氧化、硫还原腐蚀,微生物亦未对混凝土的中性化造成不利影响。本文为研究海洋混凝土工程的耐久性和防护提供了另一种思路和方法。更多还原

【Abstract】 With the growing number of marine concrete projects, the durability of concrete under the marine environment faces a great challenge, and the corrosion of steel leaded by chloride is the most serious one of those factors which affects the durability of marine concrete. It is discovered recently that there are many marine organisms which form a very thick film on the concrete surface of marine tidal zone. The film which is referred to as marine biofilm in this paper includes the shells of barnacle and oyster, it also contains a host of microorganisms and its organic metabolites, meanwhile, a certain relationship is found between the attachment of marine biofilm and the durability of marine concrete. A series of studies which based on the above phenomenon have been carried out in this paper to discover effect of marine biofilm on the anti-chloride permeability of marine concrete. All of the works are as follows:(1) Some samples are collected by core-drilling method from the concrete on a breakwater of the Qingdao Port, and the composition of the marine biofilm is analyzed.(2) The chloride accelerated penetration test are finished on the core concrete to discover what is the roles of the various components of marine biofilm which perhaps have some effects on the anti-chloride permeability of marine concrete, as well as the differences between the alive and the dead biofilm.(3) Determination of the actual situation of chloride ion content in the concrete has been done, which is helpful to analyze the role of marine biofilm on the anti-chloride permeability of marine concrete during the long-term service process.(4) By observing the micro-structure of the drilled concrete core and analyzing the compositions of the biofilm at a micro-level, effects of marine biofilm on the anti-chloride permeability of marine concrete have been confirmed.Through the above research work, results obtained are as follows: the ingredients of marine biofilm on concrete’s surface of marine tidal zone are mainly composed of the shells of oyster and barnacle, as well as some microorganisms and its organic metabolites. It makes the most effects of marine biofilm on the anti-chloride permeability of marine concrete when the biofilm is mixed of the shells of oyster and barnacle, which largely reduces the penetration amount of chloride of the concrete on tidal zone’s upper layer. Looking from the entire concrete service process, the actual chloride content of concrete of the upper tidal zone is higher than the lower, which shows the protection of biofilm against chloride penetration is not ideal. Study shows that biofilm with activity has a better effect on the anti-chloride permeability of marine concrete than the dead. The reasons of this result may have relation to the absorption of Cl- by halophile and the partly break-off of the biofilm when it is dried. The carbonization test of concrete and the differentiation of microbiology species in the biofilm indicate that there are no sulfur-oxidized and sulfur-reduced corrosion in the marine biofilm, and the microorganism in the biofilm has also no adverse effect to the neutralization of marine concrete which has been studied.This article has provided another kind of thread and method for the research of marine concrete project’s durability and protection.更多还原