Experimental Study On Mechanical Property Of Corroded Concrete

Due to the long-term action of corrosion, the performance of concrete structure becomes inferior, which decreases its durability and leads it to damage in advance, it has become an important problem for corrosion causing durability degradation of concrete structure in the field of civil engineering, and thus become a hot topic to research. On the basis of systematically summarizing the international and domestic research of concrete corrosion, mainly studied the mechanical property and the constitutive relations, the main contents are as follows:Firstly, compression strength of salt corrosion concrete was studied. Considered the effect of corrode mediator of NaCl and Na₂SO₄ on concrete, researched the compression strength of corroded concrete on the effect of two sort concentration of corrode liquor. The result indicated that the compression strength of concrete increased a little at the beginning. With the increasing time of corrode, the compression strength of concrete fall down gradually, the decline rate of NaCl corroded concrete will become more and more smaller, and the decline rate of Na₂SO₄ corroded concrete will speed up .The consistency of the liquor do not have the high effect on the strength change rate of the concrete. Based on the experiment, extract a mathematic model to compute the compression strength of corroded concrete.Secondly, Mechanical property of corroded concrete that was corroded by Hydrochloric Acid solute with PH value of 2 and 3 was studied. Damage mechanism of the corroded concrete was discussed. It is indicated that at the peak stress, mechanical property of concrete falls down with time and the solute consistency linearly. It is also shown that stress-strain curve of the corroded concrete become moderate gradually with the severe of the concrete, but the shape of the curves are very similarly, they can be fitted by the formula provided by the standard. Based on the experimental results, a numerical model is put forward to compute the compressive strength and the elastic modulus of corroded concrete. Compared with the computation results and the experimental results, the numerical model is very accurate, and it is convenient and applicable for the design of the concrete structure in the acidic environment.Finally, based on the damage mechanics, damage constitutive equations of concrete stress and strain curve were got through the method of regression analysis based on the experimental results. According to the relations of the stress and strain curve of the corrodedconcrete and the one that was not corroded, deduced the damage constitutive equations of corroded concrete. Compared with the computation results and the experimental results, good results are achieved. It indicates that this analysis method is feasible for the damage constitutive equations of corroded concrete. The work in this part is the theoretical foundation for the nonlinear FEM of the concrete structure in the acidic environment.