The Calculation Of Carbonation Crack Width Of Concrete Based On The Corrosion Expansion Stress Of Steel

It is found that most of the concrete carbonation phenomenon is serious in the process of quality inspection of the aqueduct engineering in Northwest China.The concrete cracking caused by the corrosion of reinforcing steel bars,which has affected the bearing capacity of the structure and reduced the safety of the structure.As for the crack problem,many scholars have put forward the crack control requirements.The calculation of crack width is still the focus,but for the complex influence of concrete cracking,calculation formula of crack width in the study is still widely used.With the rapid development of computer technology,computer finite element software is gradually accepted by scholars.The unique properties of the SOLID65 element in the ANSYS finite element method facilitate the simulation of concrete cracking.In this paper,the numerical model of concrete cracking caused by a uniform corrosion of reinforcement is established by finite element software ANSYS.The corrosion expansion force of concrete crack caused by the corrosion of steel bar is simulated by the thermal structure coupling model.The influence of concrete carbonation depth on crack width is studied by applying different loads to observe the crack propagation.The results are as follows:(1)The feasibility of the simulation on carbonation of concrete is analyzed according to the principle of heat conduction,establish the numerical model of concrete cracking caused by a uniform corrosion of reinforcement by finite element software ANSYS.By applying the carbonization field,the corrosion expansion force of concrete crack caused by the corrosion of steel bar is simulated by the thermal structure coupling model.The effect of carbonation on the cracking of concrete is analyzed.(2)Establish the linear regression equation between the corrosion expansion force and the carbonation depth,and the correlation is better.Using the powerful coupling function of ANSYS,the carbonization field and stress field are coupled,and the simulation results are more close to the engineering practice,which provides a theoretical basis for the later simulation of concrete cracking and crack width.(3)On the basis of the thermal structure coupling model,the crack propagation and the number of cracks of reinforced concrete is observed by applying different loads to the model,which found that the influence of load on the crack width is obvious.Under the same load,Cracking of concrete under different carbonization depth is simulated,results show that,when the carbonation depth is small,effect on the crack width is not obvious,but when the carbonation depth exceeds a certain range,the influence on the crack width is obvious.(4)Comparing the simulation results with the theoretical values,the results show that the value of crack width accuracy is satisfied;Comparing the simulated values with measured values,the results show that the relationship curves of concrete carbonation depth and the crack width is approximately the same;According to the actual measured value,the relation curve between crack width and carbonation depth is established,which is similar to the two function relation,according to the numerical value,the crack width and the carbonation depth and load relationship were fitted using the MATLAB software,which laid the foundation for the day after the durability evaluation of the project.