Corrosion of steel in concrete

The research work that is presented in this thesis aims at mapping out the various mechanisms which control the process of steel corrosion in concrete._x000D_ The process of corrosion is illustrated with a schematic model where the service Life is divided into a period of initiation and a period of propagation._x000D_ The time up to the initiation of thc corrosion process is determined by the flow of penetrating substances into the concrete cover and by the threshold concentration for corrosion to start. Theoretical models have been produced to_x000D_ approximate the time of initiation._x000D_ The rate of corrosion in the propagation period can be described by the relative humidity in the concrete and the mean temperature of the structure . Different relations between these factors and the rate of corrosion have been put_x000D_ up for different initiation mechanisms. The final state, cracked concrete covers, reduced crosssectionarea of the steel etc. is discussed in the model._x000D_ Other important factors, which have not been dealt with in the model, are also discussed._x000D_ A method for predicting service life of concrete structures is presented. The report also includes applications in various forms of the method._x000D_ The report is concluded with a documentation of laboratory investigations carried out by the author. (Author)_x000D