Influence of MSWI bottom ash as unbound granular material on the corrosion behaviour of reinforced concrete

The reutilisation of MSWI natural weathered bottom ash (WBA) in many applications such as road and underground constructions, embankments or as an aggregate replacement is a common practice in many developed countries. Its potential environmental risk has regularly been evaluated from the point of view of the leaching of heavy metals and metalloids. Nevertheless, the influence over steel rebar when reinforced concrete is exposed to the contact with WBA has been poorly assessed before. In this study, it has been possible to evaluate in terms of days the probability of corrosion in a common case of WBA reutilisation, which is in contact with reinforced concrete formulated with conventional Portland cement. The corrosion monitoring indicates that the probability of corrosion of steel rebar is higher than 90 % with a corrosion rate (CI) estimated to be 11.6 lm year-1. The aggressive conditions imposed by WBA suppose an important withdrawal if the application of reutilisation involves contact with steel rebar.The authors would like to thank VECSA and SIRUSA for their financial support as well as the R+D National Plan for financing the project BIA2011-27182 and BIA2012-32320. D.M. Bastidas would like to thank the Ramón y Cajal Program from the Ministry of Economy and Competitiveness. The research group DIOPMA would also thank Judith Gómez and Jessica Giró for the technical support.Peer Reviewe