The electrochemical behaviour of steel under polarization in porous media simulating concrete

Abstract

For simulating the corrosion of rebars in concrete, steel wire specimens were wrapped in porous polyvinyldiene fluoride sheets and placed in solutions corresponding to cement pore waters of various ages and possibly polluted with chlorides. The corrosion behaviour of steel was determined with potentiodynamic curves. For a given solution, peaks appear on these curves, at potentials which depend on the solution pH. The plots giving the peak potentials versus the solution pH include four straight parallel lines. The sizes of the pores influence these critical potentials because in small pores, the products formed at the metal-solution interface are not able to move freely.