Durability Evaluation Of Underground Reinforced Concrete Structure Based On Carbonation

With the increasing severity of civil engineering structures’durability, its research work is paid more and more attention. At the same time. Plentiful results are gained in this field. But the present research work is still very insufficient, and far fails to solve durability problems efficiently or to satisfy the need of engineering construction, especially in the field of underground structural durability. In the recent years, many large-scale underground works’appearance makes this problem more prominent and important, however, being short of experiences and deficient of relevance basic theories, it is urgent and pregnant to accelerate and delve the research of underground structures’durability, so as to prolong the planned and existing underground works’serving life.The dissertation summarizes and analyzes deeply the actuality, peculiarity, shortage and the major factors of underground structures’durability researches; brings forward the research conception generalized durability and structure deterioration grade; based on carbonization experiment of synthetically considering the influence of stress level, material performance and action time to concrete structure. Through the establishment of different water cement ratio of concrete test specimen of carbide as well as the stress of concrete specimen under different carbonization, mainly include the carbonation depth changes over time, carbonation depth change with stress situation changes, the strength of the concrete changes over time. Carbonation of concrete under natural environment is relatively slow, the carbonation depth and speed are not obvious, in order to quickly get the test data and carries on the analysis of the experiment in the laboratory accelerated carbonation of concrete for the next step was studied for the test. Concrete specimens using bracket type force f model, reflects the underground structure inhance position on the actual situation of the load.According to the experimental results, a first water cement ratio and carbonization time under different stress state of the carbonation depth of fitting, to change different water-cement ratio and carbonization time to separately fitting each carbonation depth changing with the stress, finally combined with Zhengzhou city underground garage of continuous wall material ratio and the structure of the stress state of use fixed number of year to evaluate.