QUANTITATIVE METHOD OF PRIMARY PROTECTION DESIGN OF CONCRETE PROTECTIVE LAYER UNDER ATMOSPHERIC CLIMATE EFFECTS

There are numerous cases of destruction of the concrete protective layer of reinforced concrete structures due to at-mospheric climate effects characterized by temperature, humidity, concentration of the corrosive gas. A common method of designing the primary protection of reinforced concrete structures has a prescription character. Available quantitative relations of concrete carbonation calculation due to the impact of carbon dioxide do not take into ac-count the temperature and humidity of the environment and are designed for stationary conditions. Under actual con-ditions, the temperature and humidity of the environment vary depending on the season. It should be kept in mind that the concrete carbonation takes place only during the period with positive temperature and with certain humidity. At the same time, during the negative temperature alternate freezing and thawing of concrete occurs, which increases perme-ability. Therefore, a quantitative method of designing the primary protection of concrete cover of reinforced structures is necessary, which takes into account physical and chemical process of carbonation of concrete, which is complicated by frosty destruction. Purpose. Development of a quantitative technique of designing the primary protection of con-crete protective layer in the atmospheric climate conditions, taking into account carbonization process, seasonal and daily changes in temperature and humidity (on the example of Dnipropetrovsk). Conclusion. A quantitative method of designing the primary protection of concrete reinforced structures in atmospheric climate effects was developed. Theo-retical estimation of longevity of concrete protective layer of different thickness, with different contents of cement and water-cement ratio under the criterion of carbonation complicated by frosty destruction.