Effects of slag and fly ash on reinforcement corrosion in concrete in chloride environment - Research from the Netherlands

R.B. Polder
TNO Technical Sciences, Structural Reliability, Delft, the Netherlands
Delft University of Technology, Civil Engineering and Geosciences, Delft, the Netherlands

A review is given of research on the durability performance of concrete made with blast furnace slag and fly ash related to chloride induced reinforcement corrosion, carried out in the Netherlands, where slag has been used in cement for almost a century. Results are presented from field studies on concrete in marine environment and laboratory studies involving chloride exposure. Chloride surface content, diffusion coefficient, electrical resistivity, critical chloride content and corrosion rate are discussed. Both slag and fly ash concrete show improved behaviour compared to ordinary Portland cement in aggressive environments, in particular where penetration of chloride presents the risk of reinforcement corrosion.

key words: Durability, concrete, chloride, corrosion, diffusion, resistivity, blast furnace slag, fly ash