Resistance to carbonation of concrete after re-alkalization by absorption of sodium carbonate solution

Abstract

The paper presents experimental research on the durability of a non-conventional technique for the repair of reinforced concrete damaged by carbonation-induced corrosion of steel reinforcement. The technique is called electrochemical re-alkalization and is often considered as an option for the repair of buildings, structures, and other artefacts made of reinforced concrete, for which conservation requirements are becoming increasingly important, in spite of their relatively young age. Absorption of a sodium carbonate solution is one of the processes that lead to concrete re-alkalization. The aim of the work is to investigate the contribution of this process to preventing future carbonation of re-alkalized concrete. Concrete specimens with six different compositions were initially carbonated, then re-alkalized through absorption of a sodium carbonate solution, and then exposed again to carbonation (re-carbonation). The results showed that the pH of concrete after re-carbonation was only slightly lower compared to that of realkalized concrete, highlighting a contribution of the treatment in preventing future pH reduction

Influence of Potassium-Based Alkaline Electrolyzed Water on Hydration Process and the Properties of Cement-Based Materials with Fly Ash

“…This is because AEW improved the hydration degree of the cementitious materials, and made the hydration products fill the concrete pores more evenly, thus effectively reducing the invasion degree of CO 2 . Concurrently, the alkaline environment of AEW improved the alkali reserve in the concrete structure and kept the alkaline environment in coagulation stable during the carbonation process [40,41], which proved beneficial to improving the concrete carbonation resistance.…”