Theoretical and Experimental Models to Evaluate the Possibility of Corrosion Resistant Concrete for Coastal Offshore Structures.

This study built theoretical and practical models to evaluate the corrosion resistance of concrete for coastal offshore structures in Vietnam. A mathematical model was developed in the form of a system of nonlinear partial differential equations characterizing the diffusion "free calcium hydroxide" in a solid of a concrete structure. The model describes the process of non-stationary mass conductivity observed in the "concrete structure-marine environment" system under non-uniform arbitrary initial conditions, as well as combined boundary conditions of the second and third kind, taking into account the nonlinear nature of the coefficients of mass conductivity and mass transfer . It was shown that the solution of the boundary value problem of non-stationary mass conductivity allows us to conclude about the duration of the service life of a concrete structure, which will be determined by the processes occurring at the interface: in concrete-mass conductivity, depending on the structural and mechanical characteristics of hydraulic structures, and in the liquid phase-mass transfer, determined by the conditions of interaction at the interface of the indicated phases.