Constitutive Of Corroded Concrete Under Uniaxial Compression And The Research On The Mechanical Properties Of Corroded Concrete Members

The corrosion of concrete is a complex process. Its material properties are changed after it is corroded. The corrosion mechanism of concrete under corrosion factors is clear, but the research on applying the results to evaluate concrete properties needs further analysis. In the thesis, the constitutive of corroded concrete under uniaxial compression, which is based on corroded concrete experiment, is established according to the knowledge of damage mechanics and the existent constitutive of concrete. The main works of this dissertation are as follows: 1) The corrosion mechanism of steel and concrete under the variety of corrosion factors is summarized. 2) The data of corroded concrete experiments is studied and the constitutive of corroded concrete under uniaxial compression is established by introducing the parameters about corrosion factors and its time. The uniaxial press stress-strain curve of corroded concrete is pictured by the soft-Matlab6.0 and the parameters are achieved correspondingly. 3) Finite element program about beam element including nonlinear characters of material is developed by C++. The reinforced concrete members in the environment with salt corrosion are studied by finite element method. The climb segment of the uniaxial pressure stress-strain curve of corroded concrete is divided into two parts. The first part of the climb segment has a little slope than the second part of the climb segment. Compared with the normal concrete, The first part of the declined curve of corroded concrete is steeper and the second part is gentler. The constitutive model of corroded concrete under uniaxial compression is established which has two expression and is proved by the experiment outcomes. The uniaxial pressure stress-strain curve could be founded if only the parameters about corrosion according to the corrosion experiments and other experiment results. Compared with the normal model of concrete, the constitutive model of corroded concrete is better to reflect the mechanics of corroded reinforced concrete members than in the analysis. The results of the finite element analysis of the members are closer to the experiment data with corrosion of the members enhancing.