Cracking of the Concrete Matrix Due to the Pressure of Corrosion Products in Reinforced Concrete

The processes of oxidation of metal fittings in reinforced concrete structures after a long-term operation are studied using the methods of mathematical modeling. In the calculations, the B25 (M350) concrete, from which monolithic foundations, floor slabs, columns, beams, monolithic walls and other responsible structures are manufactured was used. The corrosion process is a result of oxygen reduction with the formation of an oxide layer, which leads to a gradual fracture of concrete, that is taken into account by a scalar damage model. The influence of the oxide layer thickness on the pressure, normal and tangential stresses at the reinforcement-concrete boundary is determined. The conditions, under which the critical corrosion fracture of the concrete structure has not been reached, are determined. The structure damage decreases with an increase in the diameter of the reinforcement, a decrease in the thickness of the oxide layer as well as the total oxygen content in the concrete structure.