DURABILITY AND SERVICE LIFE PREDICTION OF CONCRETE UNDER COUPLING ACTION OF CHLORIDE PENETRATION AND CARBONATION IN SEA AIR

摘要

Based on electrochemistry theory and analysis of damage mechanism, this contribution proposed s a framework to predict durability and service life of concrete under simultaneous actions of chloride penetration and carbonation. A model is built to express the corrosion rate of steel bar as a function of pH value and logarithm of [Cl~- ] of pore solution in concrete. By virtue of accelerated spraying saline fog and carbonation experiments, the critical state equation of rebar depassivation is established. And also, a modified carbonation model is proposed to link with the critical pH value in pore solution of steel depassivation. Finally, this model is employed to investigate the influence of mineral admixture on the service life of concretes at various water-to-binder ratios.