Relation between Crack Width and Diameter of Rebar Loss Due to Corrosion of Reinforced Concrete Members

Abstract

Reinforcement corrosion leads into several damages which influence the structural load-bearing capacity, among which can be mentioned the cracking of concrete cover. This work study formulations to estimate the crack width of structural elements from the data of corrosion rate measured in two structural elements, made in 1990, with chlorides added in the concrete mix and laboratory test from other authors. The structural elements, one T beam and one column, were exposed at the atmosphere of Madrid, Spain. Two expressions have been fitted to the results: w = k P x / (c/φ) and w = k P x / R o , where w is a crack width in the time, k is a proportional factor, P x is the corrosion penetration in the time, c/φ is the concrete cover/diameter relation and R o is the original radius of the bar. The first expression has resulted the most adequate.

Predicción de la vida útil en servicio de edificios de 50 años expuestos a ambientes marinos

“…Some models discuss the time needed to generate cracking of the concrete as a function of the concrete characteristics, its physical properties and the accumulation of corrosion products (Liu and Weyers, 1998;Pantazopoulou and Papoulia, 2001), or assume good adherence behaviour at the steel/concrete interface to obtain an expansion threshold below which no crack propagation occurs (Leung, 2001). Other authors have modelled the critical corrosion penetration to initiate cracking and its relation with the reinforcement diameter (Andrade et al, 1993;Torres-Acosta and Martínez-Madrid, 2003;Muñoz et al, 2007;TorresAcosta and Castro-Borges, 2013), or the reduction in the steel section due to corrosion considering the concrete cover/rebar diameter relation and the characteristics of the concrete (Vidal et al, 2004;Bossio et al, 2015;Fahy et al, 2017).…”