Early Deterioration of Civil Engineering Structures Under Organic Salts and Chloride Exposure

The premature deterioration of reinforced-concrete structures exposed to chloride and organic salts is a coupled physicochemical, electrochemical, transport, and mechanical phenomenon. Chloride ionspenetrate concrete through diffusion, capillary suction, convection, and electromigration. Organic salts, such as acetates and formates used in de-icing systems, may produce additional deterioration through pore-solution modification, complexation with cement hydration products, alteration ofcalcium–silicate–hydrate phases, osmotic pressure, accelerated moisture transport, and electrochemical interaction with reinforcing steel. This paper presents an advanced theoretical framework for describing the early deterioration of cementitious structures using reactive-transport theory, electrochemical thermodynamics, porousmedia physics, and fracture mechanics. The proposed model couples the Nernst–Planck equations,Darcy flow, moisture transport, chloride binding, chemical equilibrium, carbonation, corrosion kinetics, and damage evolution. The general governing system is formulated as a nonlinear chemo–hygro–thermo–electro–mechanical problem.The deterioration process is governed by the interaction between free ions, bound ions, pore-fluid saturation, temperature, electrical potential, pH, porosity, permeability, and reinforcement corrosion. A service-life criterion is proposed based on the time required for the chloride concentration at the reinforcement depth to exceed a critical depassivation threshold, followed by corrosion-induced cracking.