高原环境下混凝土劣化机理及施工质量对其影响

发布时间：2018-04-23 17:53

本文选题：高原环境 + 混凝土　；参考：《西南交通大学》2017年硕士论文

【摘要】：钢筋混凝土作为一种常见的建筑材料,由于性能优越、耐久性好、价格低廉,在工程建设中被广泛使用。由于国内外均发生了钢筋混凝土未达到设计使用年限而出现过早损坏的情况,学术界开展了大量研究,以明确钢筋混凝土劣化机理,并通过设计、施工规范对混凝土劣化予以预防。但是针对高原环境下混凝土劣化机理的研究相对较少,混凝土劣化与施工质量的关联更缺乏研究。鉴于此,本文立足于现有理论基础,结合高原施工的实际工程,针对高原地区施工具体情况,重点探讨高原环境下导致混凝土劣化的主要因素和如何通过加强施工管理、改良施工技术以提升混凝土质量,从而抑制高原地区混凝土劣化,最终达到提升混凝土耐久性能的目的。本文首先通过追踪工程实例明确了高原环境下对混凝土劣化影响最大的主要在于冻融循环造成的破坏,同时高原独特的气候条件造成混凝土碳化与内陆存在一定差异,向阳、背阴侧碳化速度不同将导致向阳侧混凝土更早中性化,失去对钢筋的保护而导致结构过早破坏。其次,通过对部分项目进行施工技术上的调整,寻找对抗冻融循环和混凝土表面碳化对钢筋混凝土造成伤害的办法,主要包括以减小孔隙率为目的提升混凝土密实度、以防止外界水渗入混凝土内部为目的的防水措施和以提高混凝土早期强度为目的的添加外加剂等方法。论文研究结合施工分别单独调整某个技术措施,以寻找影响混凝土劣化的主要原因,以寻求解决混凝土劣化最有效的措施。再次,结合已发生的高原工程出现混凝土碱骨料反应的实际,总结了在施工管理中预防碱骨料反应应注意的事项和可采取的技术措施,主要包括通过控制碱含量、控制骨料活性物、防止水渗入等方式预防碱骨料反应。最后,结合高原环境条件和施工实际,从管理上提出增进混凝土施工质量的措施。
[Abstract]:As a common building material, reinforced concrete is widely used in engineering because of its superior performance, good durability and low price. Because of the premature damage of reinforced concrete which has not reached the design life at home and abroad, the academic circles have carried out a lot of research to clarify the deterioration mechanism of reinforced concrete, and through the design, Construction code to prevent concrete deterioration. However, there are few researches on the deterioration mechanism of concrete in plateau environment, and the relation between concrete deterioration and construction quality is even less. In view of this, this paper bases on the existing theory foundation, unifies the plateau construction actual project, according to the plateau area construction concrete situation, emphatically discusses the plateau environment causes the concrete deterioration main factor and how to strengthen the construction management, In order to improve the quality of concrete and restrain the deterioration of concrete in plateau area, the purpose of improving the construction technology is to improve the durability of concrete. First of all, by tracing the engineering examples, this paper makes it clear that the greatest influence on concrete deterioration in plateau environment is mainly caused by the damage caused by freeze-thaw cycle, and at the same time, the concrete carbonization caused by the unique climatic conditions in the plateau is different from that in the interior. Different carbonation speed of the back side will lead to the early neutralization of the concrete in the sunny side, and the loss of the protection of the reinforcement will lead to premature destruction of the structure. Secondly, by adjusting the construction technology of some projects, to find ways to resist freeze-thaw cycle and carbonization of concrete surface to cause damage to reinforced concrete, mainly including raising the density of concrete for the purpose of reducing porosity. The waterproof measures aimed at preventing the external water from infiltrating into the concrete interior and the adding of admixture to improve the early strength of concrete are discussed. In order to find out the main causes of concrete deterioration and to find out the most effective measures to solve the deterioration of concrete, some technical measures are adjusted separately in combination with construction in this paper. Thirdly, combined with the actual occurrence of concrete alkali aggregate reaction in plateau engineering, this paper summarizes the matters needing attention and the technical measures to be taken to prevent alkali aggregate reaction in construction management, including mainly through controlling the alkali content. Control aggregate activity, prevent water infiltration and other ways to prevent alkali aggregate reaction. Finally, combined with the environmental conditions of plateau and construction practice, the measures to improve the quality of concrete construction are put forward from the point of view of management.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528;TU755

【相似文献】