Hydrogen permeation due to uniform, pitting, and crevice corrosion of carbon steel in concrete simulated media

Aiming to simulate concrete aging, the influence of O-2, Cl--,Cl- and pH of simulated concrete pore solution on the uptake of H by steel were studied. No significant H uptake could be sensed during pitting or uniform corrosion at pH above 9. When crevice corrosion was induced, H uptake was significant, and the permeation current continuously increased after its nucleation. Numerical modeling using the Nernst-Plank equation coupled with electroneutrality confirmed a narrow potential-pH range where Fe dissolution and HER might occur inside the crevice, despite the alkaline pH in the bulk of the solution.