Today, there are several methods for predicting the durability of reinforced concrete structures. In most cases, one of the dominant destruction processes is taken into account – either carbonization or chloride penetration. Experimental results and field observations show that this is an unrealistic approach. Therefore, it is necessary to develop a method for determining the durability of concrete under combined impacts, i. e. with the penetration of chlorides into it and mechanical load. The paper describes in detail an experimental method for studying the effect of mechanical load on the penetration of chlorides into the pore space of cement-based materials. A test method is presented that makes it possible to determine realistic diffusion coefficients of chloride ions in concrete under compressive or tensile stress. As a result of the experiments carried out, it has been determined that the combination of mechanical loads and environmental influences can be much more significant than just environmental influence without the influence of mechanical loading. In fact, the service life of reinforced concrete structures depends on many possible combinations of mechanical loads and environmental influences, including freeze-thaw cycles. Thus, cracks formed during freeze-thaw cycling should be taken into account in tests of combined environmental and mechanical stress in order to better understand and systematically describe the effect of such exposure on the durability of concrete. For reliable prediction of the service life of reinforced concrete structures, it is also necessary to take into account the influence of the applied cyclic stress.

The chloride content and the pH value of the pore solution in the steel reinforcement zone are the determining parameters of the initiation and rate of corrosion. The pore liquid of the cement stone was isolated from the pore space by high pressure during the study. The effect of the water-cement ratio, age, and the addition of chloride to the fresh mixture on the chloride content in the pore solution was evaluated by ion chromatography. At the same time, the pH value of the pore solution is determined. The dissolved chloride content decreases with an increase in the water-cement ratio. The amount of bound chloride increases over time, but decreases with a decrease in the content of dissolved chloride in the pore solution. A significant effect of carbonation on the content of dissolved chloride in the pore liquid was noted. With complete carbonation, the content of dissolved chloride in cement stone increases by 2-12 times. The bound chloride decreases by 27%-54%, the pH value decreases from 13.2 to 8.0 due to carbonation. It can be concluded that carbonation not only reduces the pH value, but also releases bound chloride. This is one of the obvious reasons why the combined effect of chloride penetration and carbonation accelerates the corrosion of steel and shortens the service life of reinforced concrete structures.

Corrosion reinforcement marine hydraulic structures due to chloride aggression and carbonization of concrete leads to a sharp decrease in thesafety of the structure. The steel reinforcement will be subjected to a so-called depassivation process, once the chloride concentration on surface exceedsa certain threshold concentration, or the pH value in the protective layer of concrete decreases to a threshold value due to carbonation. Electrochemicalreactions begin to occur with the formation of corrosion products with the penetration of oxygen on the steel reinforcement surface. This leadsto cracking of the protective layer of concrete. It should also be taken into account that, due to corrosion mechanisms, the cross-sectional area of thereinforcement also decreases. The article suggests a method for predicting the complex degradation of reinforced concrete structures, taking into accountvarious mechanisms of corrosion wear, which will allow developing effective ways to improve the durability and maintainability of structures operatedin the marine environment.

Reinforcement corrosion of marine and coastal hydraulic structures due to chloride aggression and concrete carbonization leads to a sharp decrease in structure safety. The reinforcement is subjected to a depassivation process as soon as a chloride concentration on its surface exceeds a certain threshold concentration, or the pH value in a concrete protective layer is decreased to a threshold value due to carbonation. Electrochemical reactions are realized with formation of corrosion products due to penetration of oxygen up to reinforcement surface. This leads to cracking of the concrete protective layer and decrease in reinforcement cross-section. The paper proposes a method for predicting a complex degradation of reinforced concrete structures with due account of various mechanisms of corrosion wear that allows to develop efficient methods for improvement of structure durability and maintainability which are operated in the marine environment. A methodology for forecasting of reinforced concrete service life prediction has been developed under a combined effect of carbonization and chloride aggression while using finite-difference and probability models. The paper takes into account initiation periods of reinforcement corrosion and propagation periods for conditions of Sakhalin shelf zone. Field surveys of Kholmsk and Korsakov port facilities are presented in the paper. Carbonization front and chloride content have been estimated according to depth of the concrete protective layer. The paper proposes a model that allows to determine an average period prior to repair while taking into account rate of concrete protective layer degradation caused by simultaneous action of two corrosion processes: carbonization and chloride aggression.

Corrosion reinforcement marine hydraulic structures due to chloride aggression and carbonization of concrete leads to a sharp decrease in the safety of the structure. The steel reinforcement will be subjected to a so-called depassivation process, once the chloride concentration on surface exceeds a certain threshold concentration, or the pH value in the protective layer of concrete decreases to a threshold value due to carbonation. Electrochemical reactions begin to occur with the formation of corrosion products with the penetration of oxygen on the steel reinforcement surface. This leads to cracking of the protective layer of concrete. It should also be taken into account that, due to corrosion mechanisms, the cross-sectional area of the reinforcement also decreases. The article suggests a method for predicting the complex degradation of reinforced concrete structures, taking into account various mechanisms of corrosion wear, which will allow developing effective ways to improve the durability and maintainability of structures operated in the marine environment.

On the coast of the Russian Far East the climate is monsoon, which is most pro-nounced in the south and northeast waning. Seasonal change of oceanic and continental influence is reflected in the nature of the climate: summer is moderatelywarm and rainy, winter is cold and snowy. On Sakhalin winters are less severe than on the mainland. In Kamchatka, where the winters are milder, the influence of the continental monsoon less. In the southern part of Primorye snow is so small that there is in the rivers spring flood. In the north of the Amur region, Sakhalin, Kamchatka rainfall and snowpack increases. In the summer is dominated by southeast wind, which spread to the continent moist Pacific air. During the year, between the Pacific Ocean and the south of the Far East there is an intensive exchange of air masses. Seasonal change of air currents is determined by the thermal contrast between the continent and the ocean. During the year passes over the area to an average of 100 cyclones (3–6 per month during the cold period, and up to 3 – warm), which are ac-companied by increased wind, cloudy weather with precipitation, and in late summer and early au-tumn, typhoons observed outputs. Typhoons are accompanied by stormy winds reaching speeds of over 40 m / sec. and heavy rains. A wide variety of observed in the distribution of precipitation. The Chukchi-Anadyr area for the warm period falls to 200–250 mm in the north of the Sea of Okhotsk – 400–500 mm, in intermountain basins up to 250–300 mm. To the south the amount of precipitation increases to 500 to 600 mm in the Amur region and 900–1000 mm on the western slopes of Sikhote Alin. In the course of the annual maximum rainfall in the second half of the summer, but there are rainy June and September. No wonder that in such conditions, corrosion, material of hydraulic structures is most intense. Concrete and cement stone reinforced concrete structures exposed to corrosive attack, particularly the aggressive action of CO2 common acid gas, which is to neutralize the surface layer of concrete and the formation of the compounds that affect its properties. The article discusses the impact of the environment model south of the Far East, mainly due to the impact on hydraulic reinforced concrete structures of carbon dioxide in the environment, with subsequent corrosion of concrete and reinforcement.