A model for time-to-cover cracking of reinforced concrete due to rebars corrosion

S. B. FARINA; G. S. DUFFÓ

Integral Service Life Modelling of Concrete Structures

Rilem Publications

Lugar: Bagneux-France; Año: 2007; p. 277 - 284

Service life of concrete structures is frequently limited by reinforcement corrosion. The formation of various compounds that occupy a volume much greater than the original steel generates expansive pressures on the surrounding concrete. The pressure builds up to levels that cause internal cracking around the bar and results in the through cracking of the cover concrete. In the present work, a simple analytical model was formulated to determine the time-to-cracking of cover concrete depending on the mechanical properties of the concrete, the concrete cover depth, the diameter of the reinforced bars, the corrosion current density and the type of compound formed during the corrosion process. The model (in its present version) assumes a constant rate of rust production and so yields the most conservative time-to-cover cracking values. Calculated time-to-cover cracking values were compared with published experimental data and reasonably good agreement was obtained. However, it was found that results are significantly influenced by the type of corrosion product considered.