The kinetic competition between transport and oxidation of ferrous ions governs precipitation of corrosion products in carbonated concrete

• DOI: 10.21809/rilemtechlett.2018.57
• Publication Date: 2018-09-14T15:40:58Z
• Authors: Matteo Stefanoni; Zhidong Zhang; Ueli Angst; Bernhard Elsener
• Keywords: Spall

Corrosion products, originating from steel corrosion and precipitating in the concrete pore system, can lead to cracking spalling of cover. Related premature structural repair causes high costs. Thus, reliable quantitative models are needed, which currently do not exist. Here, we present a new conceptual model describe fate ferrous ions that released at surface during process. The key novelty our approach be found explicitly considering kinetics oxidation transport Fe2+ solution. These two processes constantly dilute concentration competition with supply anodic iron dissolution reaction. We use numerical elucidate described is fastest. results find good agreement experimental data reveal under natural conditions, hardly reach saturation level, permits diffusion products up millimeters away without necessarily leading expansive stresses. Under accelerated however, precipitation forced immediately surface. This fundamentally changes mechanism questions relevance such tests related models.