季冻区桥梁结构混凝土工程质量控制关键技术研究

发布时间：2018-04-30 20:24

本文选题：抗冻混凝土 + 密实骨架堆积法　；参考：《大连海事大学》2014年硕士论文

【摘要】：季冻区自然环境复杂,桥梁结构混凝土在冻融循环等因素的作用下,容易出现严重的质量病害,影响结构耐久性。如何提高季冻区桥梁结构混凝土的抗冻性能,并对其耐久性进行快速准确评价成为研究热点。本文在分析季冻区桥梁结构混凝土主要病害及成因的基础上,开展了混凝土抗冻配合比设计、耐久性能评价以及施工质量控制等工作。具体研究内容如下：(1)对吉林省高速公路及普通公路在役桥梁的主要病害进行了调查,对结构混凝土耐久性病害成因进行了分析。结果表明：结构混凝土的抗渗、抗冻设计不合理、施工过程控制不严格和冻融循环作用是影响混凝土耐久性的主要因素。(2)针对普通混凝土配合比设计存在的局限性,提出了基于密实骨架堆积理论的结构混凝土抗冻配合比优化设计方法；采用正交试验法,以坍落度、含气量、抗压强度为试验指标,确定了抗冻混凝土矿物掺合料的最佳掺量。(3)分别开展了单掺矿物掺合料混凝土的抗水冻性试验以及双掺混凝土的抗盐冻试验,确定其抗冻性能。采用Torrent渗透性测试仪和Autoclam压力渗透检测仪,测定混凝土渗气性、渗水性与耐久性的关系；在此基础上,提出了混凝土耐久性的现场无损检测方法,为快速、定性定量的评价结构混凝土的耐久性能提供技术条件。(4)分析了影响季冻区结构混凝土施工质量的主要因素,通过室内试验和现场调研,提出了结构混凝土施工质量控制关键技术；并对实际工程中混凝土质量控制辅助产品进行对比研究。(5)以大广高速宁江松花江特大桥为实体工程,进行了掺入Ⅰ级粉煤灰和高效引气减水剂的混凝土优化配合比设计、结构混凝土现场渗透性能检测试验以及两年的跟踪观测,验证了本文所提出技术的有效性和准确性。
[Abstract]:Due to the complex natural environment and the concrete of bridge structure under the action of freeze-thaw cycle, it is easy to appear serious quality diseases and affect the durability of the structure. How to improve the frost resistance of bridge structure concrete in seasonal freezing area and evaluate its durability quickly and accurately has become a hot research topic. On the basis of analyzing the main diseases and causes of concrete of bridge structure in seasonal freezing area, this paper has carried out the design of concrete anti-freezing mix ratio, the evaluation of durability and the quality control of construction, etc. The specific research contents are as follows: (1) the main diseases of highway and existing bridges in Jilin Province are investigated, and the causes of durability diseases of structural concrete are analyzed. The results show that the impermeability and anti-freezing design of structural concrete are unreasonable, the construction process is not strictly controlled and the freeze-thaw cycle is the main factor affecting the durability of concrete. Based on the theory of dense skeleton stacking, the optimum design method of antifreeze mixture ratio of structural concrete is put forward, which is based on the orthogonal test method and takes slump, gas content and compressive strength as test indexes. The optimum content of mineral admixture of antifreeze concrete was determined. The test of water freezing resistance of concrete with single mineral admixture and the test of salt freezing resistance of concrete with double admixture were carried out, and the frost resistance of concrete was determined. Torrent permeability tester and Autoclam pressure permeation tester are used to measure the relationship between concrete permeability, water permeability and durability. On the basis of this, the field nondestructive testing method of concrete durability is put forward. Qualitative and quantitative evaluation of the durability of structural concrete can provide technical conditions. (4) the main factors affecting the construction quality of structural concrete in seasonal frozen area are analyzed, and the indoor test and field investigation are carried out. The key technology of structural concrete construction quality control is put forward, and the concrete quality control auxiliary products in practical engineering are compared. The optimization mix ratio design of concrete mixed with grade I fly ash and high efficiency air entrainer water reducer, the field permeability test test of structural concrete and the tracking observation for two years have been carried out. The validity and accuracy of the proposed technique have been verified.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.57

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