【作者】 张健；

【导师】 郑秀华；

【作者基本信息】 哈尔滨工业大学 ， 交通运输工程（专业学位）， 2017， 硕士

【摘要】 混凝土具有适用性广泛、造价低廉等优点而被大量应用于城市排水和污水处理系统工程中。城市排水管道是现代化城市建设不可缺少的重要基础设施,也是体现一座城市现代化的重要指标之一,对城市经济发展具有十分重要的影响。提高混凝土耐久性,已经成为当今土木工程界急需解决的重要问题。在城市污水环境下,污水的处理构造物和运输构筑物混凝土要受到各种强酸、强碱、有机物、无机物和微生物的腐蚀,同时还受到复杂的机械冲击与磨蚀及气候因素的共同作用。污水环境下混凝土的劣化腐蚀是各种因素的叠加的结果,而且在水位界面附近的干湿循环与水下区域的混凝土腐蚀机理、过程不尽相同。本课题针对天津市生活污水的实际情况,研究其对混凝土构筑物的腐蚀机理,并积极应用新型材料提高混凝土的耐腐蚀性能。首先对天津市污水环境进行采集然后模拟,再在厌氧环境与干湿循环条件下通过与清水条件下的强度进行对比,并通过添加玄武岩纤维、粉煤灰、引气剂等方法,研究混凝土耐腐蚀性能的衰减规律,预测不同的改性混凝土在不同环境下的耐久性及使用情况,对污水环境下构造物混凝土的结构设计及剩余使用寿命等提供重要依据。研究结果表明:干湿循环环境对混凝土的腐蚀明显加剧,玄武岩纤维的掺入可以明显改善混凝土的耐腐蚀性能,在玄武岩掺量为0.10%时改善效果最为明显。粉煤灰的掺入可以明显改善混凝土的耐腐蚀性能,粉煤灰掺量的继续提高,并不能继续提升其耐腐蚀性能,在粉煤灰掺量为20%左右改善效果最为明显。混凝土含气量在一定范围内可以明显改善混凝土的耐腐蚀性能。但是,混凝土含气量的提高会明显降低抗压强度。含气量提高到一定数值后,不但强度下降明显,耐腐蚀性能并没有继续得到很大幅度地提高。综合考虑不同环境下不同含气量混凝土的耐腐蚀性能,最佳含气量为3%~4%。更多还原

【Abstract】 Concrete as a composite material,with a wide range of applicability,low cost and other advantages have been widely used in city drainaga and sewage treatment systems engineering.Urban drainage pipeline is an important and indispensable facility in modern urban construction.It is also an important symbol of modernization of a city,and has a very important impact on the city’s economic development.Improve the durability of concrete has become an urgent problem in today’s civil engineering industry to solve.In the urban sewage environment,the sewage treatment structure and transport structure concrete to be a variety of strong acid,alkali,organic matter,inorganic and microbial corrosion,but also by the complex mechanical impact and abrasion and climate factors together.With the rapid development of China’s economic construction and urbanization process,urban sewage(including industrial wastewater and domestic sewage)has become a more prominent problem in current environmental management.At present,most of our cities use concrete underground underground pipe,but the traditional concrete pipe corrosion resistance is poor,long service in the sewage environment has a different degree of corrosion damage.The deterioration of concrete under the environment of sewage is the result of the superposition of various factors,and the mechanism of concrete corrosion is not the same in the wet and dry cycle near the water level interface and the underwater area.In this paper,the corrosion mechanism of concrete structure is studied according to the actual situation of Tianjin domestic sewage,and the application of new materials to improve the corrosion resistance of concrete.Under the condition of anaerobic and dry-wet cycle,the attenuation law of concrete structure is studied,and the durability of different modified concrete under different environment is predicted.It provides important basis for the design of concrete under the environment and prolonging the service life of concrete.The results show that it is shown that the corrosion of concrete is obviously aggravated by the dry and humid environment,and the incorporation of basalt fiber can improve the corrosion resistance of concrete obviously.When the basalt content is 0.10%,the effect is the most obvious.The incorporation of fly ash can significantly improve the corrosion resistance of concrete,fly ash content continues to improve,and can not continue to enhance its corrosion resistance,the fly ash content of about 20% to improve the effect of the most obvious.Concrete gas content in a certain range can significantly improve the corrosion resistance of concrete.However,the increase in concrete content will significantly reduce the compressive strength.Gas content increased to a certain value,not only the intensity decreased significantly,corrosion resistance and did not continue to be improved.Considering the corrosion resistance of concrete with different gas content in different environments,the optimum gas content is 3% ~4%.更多还原