Evaluation of Penetrating Sealers on Service Life of Concrete Infrastructure

Abstract

In cold regions, thermal cycles and corrosion of reinforcements are the main factors that cause deterioration in concrete structures. Per each storm event, salt is used to melt snow and ice. Ultimately, water contains aggressive substances such as chloride that penetrate the concrete. When saturated concrete experiences FT cycles, it results in internal frost damage as well as surface salt scaling. The salt solution that contains chloride ions, at normal temperature, reaches calcium hydroxide and forms calcium oxychloride which is another form of damage observed mainly in concrete joins. On the other hand, infiltration chloride ions ultimately disrupt passive film around steel reinforcement and result in corrosion of steel. A recent trend is to extend the service life of existing infrastructure beyond the designed service life. This trend serves both sustainability, using less natural resources, and carbon footprint, generating carbon in the production of new materials. Therefore, in advanced countries, preservation, repair, and restoration as much as building new structures are important. This research explores the effect of different families of penetrating sealers on the durability performance of concrete. A large variety of penetrating sealers possessing different modes of action available in the market, research is needed to quantify and compare sealer impact on concrete durability. It should be mentioned that, along with reinforced concrete structures, a large portion of this dissertation focuses on the durability of joints in concrete pavements. The dissertation includes a selection of papers investigating a variety of important aspects of concrete joint durability. The papers include: • Evaluating penetrating sealer performance, such as depth of penetration, and wettability, • Effect of sealers on the freeze- durability of concrete joints, • Effect of sealers on the potential of calcium oxychloride formation, and • Effect of sealers on chloride ion penetration and concrete surface abrasion. The investigation conducted on concrete that considers durable concrete in terms of air voids and incorporating supplementary cementitious materials along with concrete possessing durability issues, such as improper air void system concrete, concrete contains aggregate that is susceptible to D-cracking, and concrete susceptible to form expansive calcium oxychloride. The results, presented in Chapters 3-6, show that the rate and timing of sealer application substantially affect sealer performance. Most sealers reduced both water absorption and chloride ions penetration. In addition, the durability of concrete varied depending on sealer type and mode of action. All sealers almost eliminated the potential of calcium oxychloride formation.