Study Of Chemical And Mechanical Damage Of Concrete Based On Calcium Ion Leaching

The concrete is widely applied as the building material, thus it also is frequently tested and influenced by many kinds of environment. Under the environment of the mobile soft water and corrosive chemistry solution, the chemical and mechanical damages of concrete, specially the combined effect of the two ones are main reasons for the deterioration of concrete material. Based on the Gerard calcium ion leaching theory, the occurrence mechanism of these two kinds of damages is studied, which is helpful to forecast the service life of concrete structure under the corrosive environment.The calcium plays an important role in being a indicator in cement clinke, the hydration reaction and the hydrated product. Starting from the Gerard calcium ion one-dimension leaching simplified model, with the calcium ion concentration taken as a parameter, the calcium ion concentration variation mode of a concrete specimen caused by the leaching time and position changes in concrete-hole solution under the mobile soft water environment is simulated. The simulation is made by establishing and dividing the finite element mesh which is dense and changes gradually.The calcium ion leaching is an extremely slow process, therefore, by using the ammonium nitrate solution with concentration of 480g/l to accelerate the calcium ion leaching. The chemical reaction mechanism of how the ammonium nitrate solution speeds up the calcium ion leaching is thoroughly studied in this article. And the calcium ion concentration evolutionary process in the concrete hole solution with the ammonium nitrate accelerating is simulated.According to the changing of the calcium ion concentration in the concrete hole solution, the influence of the chemical damage on the concrete constitutive relations is studied. By working out the finite element program and applying displacement-load, the stress situation of concrete is simulated when only mechanical damage and simultaneously chemical and mechanical damage is considered. Finally, according to the chemical and mechanical damage theory, the mechanics performance of a concrete tube structure suffered some chemical damage are simulated. The chemical damage of concrete, specially mutual function with the mechanical damage, provides us a new direction to study the damage mechanism of the concrete.