چكيده به لاتين
Concrete is one of the most basic materials used in construction and civil engineering. One of the most important issues in the design and construction of concrete structures is their service life. But its durability against aggressive environmental conditions, and especially the acidic effects of ion sulfate penetration, has reduced durability in some areas, especially coastal and marine areas. The most important and commonly used materials that contain sulfate, which will cause concrete damage, are magnesium sulfate, sodium and calcium. In the presented models, there is no exact relationship between the depth of penetration of ion sulfate inside the concrete matrix, or with various assumptions to simplify the empirical relations. In this study, using the differential equation governing the ion sulfate penetration, which is based on the Fick Second Law, which is typical of conventional concrete, is initially a numerical relation for the amount of sulfate ion at a depth and at a desired time It was then proposed to use the mathematical relations expressed in terms of penetration and its use along with the method used by other researchers for the amount of sulfate ion at the desired depth and time and according to the existing environmental conditions. In the corrected relationship, using the performed modeling, it was determined that the effect of buffer coefficient on the depth of penetration of sulfate ion was very small. In the results, it was determined that the highest intensity and rate of penetration of ion sulfate into concrete occurs in the first 10 days and after about 500 days of external attack of sulfate ion to the concrete matrix, the penetration process is almost constant and the amount of sulfate ion per Depth remains roughly constant.
