ASSESSMENT OF THE IMPORTANCE OF INITIAL CARBONATION OF CONCRETE IMMEDIATELY AFTER ITS PRODUCTION

The article shows the importance of objective assessment and forecasting of concrete carbonation as the main type of its corrosion, determining the durability of most of the operated and designed reinforced concrete elements and structures. A method for calculating the limiting value of the carbonate component (КС10 index) is given based on the condition of formation of 10 % Са(ОН)2 after cement hydration. Based on the results of the analysis of previously obtained dependencies of the carbonate component distribution (КС0 index) over the cross-section of freshly made concrete of compressive strength classes С12/15–С50/60 using the calculated values of the КС10 index, the values of the depths of complete carbonation of the cement-sand fraction of concrete of various compressive strength classes (compositions) were obtained. It has been shown that immediately after production (using heat and moisture treatment), the protective layer of concrete of any class of compressive strength is carbonized to a significant depth, which must be taken into account in predictive models of concrete carbonization.