Research On Concrete Carbonization And Its Influence On The Mechanical Behavior Of Underground Structurs

Concrete is one of the important building materials applied in underground structure, its performace has a decisive influence on the quality and the life of the underground engineering. The ability on resistance to carbonation is one of the important indicators on concrete durability. Since environment of underground space is relatively closed and crowd, carbonization is more serious. Therefore it is necessary to conduct a research and demostration on concrete structure and its carbonization in underground engineering. So far many scholars have study on the carbonization mechanisim, carbonization factors and predicion of carbonization depth. But most of these studies are stayed in the perspective of concrete material itself, carbonization’s influence on structure is barely studied. In practical life, we need to learn more about the carbonization’s influence on structure. Accordingly, this paper has a further study on the mechanical behavior of the concrete carbonization based on the carbonization test. The main research contents are as follows:(1)Under the concrete carbonation test, the variation of concrete’s mechanical parameters (including modulus of elasticity and compressive strength) is studied and the effect of carbonization on mechanical behavior is analyzed.(2)By using three-dimensional numerical display, we should observe the meso-structure of carbonized concrete and find the distribution of carbonization area, partial carbonated area and non-carbonated area.(3)Based on the experiment, we explore the law of internal force and displacement of tunnel lining with varying degrees of carbonization through ANSYS and reveal the carbonation effect on the mechanical behavior of the tunnel, and evaluate the safety of the underground structure synthetically by the research results.The law of concrete carbonation depth varying with time and variation of concrete’s compressive strength and elastic modulus after carbonation is obtained through the research. The distribution of carbonization area, partial carbonated area and non-carbonated area is also obtained. This paper analyzes carbonation’s impact on the mechanical behavior of tunnel through the numerical calculation.