Relation Between Corrosion Degree And Pressure Needed To Produce The First Crack And Evolution Of Crack Width In Natural Exposure

Abstract

Reinforcement corrosion leads into several damage types which influence the structural loadbearing capacity, among which can be mentioned the cracking of concrete cover. This work presents results of crack width generated in concrete elements fabricated in 1990 with chlorides added in the mix and exposed to the natural atmosphere of Madrid-Spain climate. These elements, one T beam and one column. Two expressions have been fitted to the results: w = k Px / (c/φ) and w = k Px / Ro, where w is a crack width in the time, k is a proportional factor, Px is the corrosion penetration in the time, c/φ is the concrete cover/diameter relation and Ro is the original radius of the bar. The expressions were also fitted to results taken from the literature made applying a current. The beam shows larger crack widths than the beam and the accelerated tests give intermediate results. Based in all the results, although the scatter is important, it has been calculated the k and k’ slopes which resulted respectively in values of 9.5 and 35.5