The Study Of Damage Mechanism And Evaluation Of Concrete Under The Erosion Of Wind-blown Sand Environment

With China’s economic development, the concrete structure is a widely used structure form. However, affected by the severe environment like sand storm, temperature, and corrosive mediums including acid, alkali and salt, the durability of structure decreases which leads to the potential safety hazard has negative impacts on people’s daily lives.In this paper, the desert regions of Midwest Inner Mongolia are researched where the concrete structure in highways and viaduct have been influenced by natural disasters like sand storm for a long time,as well as low durability and safety of the structure. Gradually, the working life of the concrete structure will be shortened. O n the basic study of the climatic features of the Midwest Inner Mongolia, the fundamental theories like physical and mechanical property of concrete material are discussed here. In addition, by adopting the method of blown-sand jet, the paper studies the erosive wear quality and the erosion rate under different intensity and erosion parameters. This method can precisely assess the erosion rate of the concrete structure which makes the experiment of more practical meaning. Specific contents are as follows:1. In this paper, large amounts of researches are conducted to the sandstorm meteorolo gical environment in mid-west Inner Mongolia based on which the erosion parameters are selected. On the basis of the natural environment and climatic features, the anti-erosion experiment of the concrete structure is designed in three types with different intensities and grades. Then the comparison research of the erosion parameters of concrete structure under different intensities and environment is carried out.2. Sand-airflow jet method is adopted to carry out the research on erosion resistance of the concrete structure. According to the analysis of the results, it shows that:(1) the erosion rate of concrete structure under the same intensity grows as the sand erosive angle increases and the b iggest one appears in 90°;(2) the erosion rate of concrete struc ture under the same strength increases along with the improvement of erosion speed which implies an exponential relationship between them;(3) the erosion rate of concrete structure under the same strength will increase at first and decrease then along wit h the increase of the falling rate of sand;(4) the experiment shows that there is no obvious incubation period during the erosion process but the rise and stable periods. Through the investigation on the surface of the erosion sector by scanning electron microscope, the failure mechanism is the similar surface scratch under low angle attack erosion and the impact indentation fractionunder high angle attack erosion.3. Through the establishment of contact mechanics model of sand flux’s erosion, the erosion mechanics behavior and theories of concrete under the sand flux are analyzed.4. A new assessing method and corresponding evaluation formula for erosion resistance degree subject to sandstorm are proposed in this paper. Using this evaluation formula, the relationship between the weight of concrete erosion and the erosive speed and erosive angle is calculated out. In addition, by comparing the experimental results and the results from evaluation formula, it shows the reliability and feasibility of the evaluation formula.