Overview of High-Molecular-Weight Methacrylate for Sealing Cracks in Concrete Bridge Decks

Abstract

Cracking in concrete bridge decks is widely regarded as a long-term durability and maintenance problem that requires attention. These cracks propagate through the deck and allow rapid ingress of moisture and chlorides into the concrete interior, leading to excessive deterioration from rebar corrosion. In California, high-molecular-weight methacrylate (HMWM) is frequently used as a crack sealer, with millions of dollars spent annually on maintenance applications of methacrylate on state-owned bridges. The work presented reviews previous research regarding the effectiveness of concrete bridge deck sealers and the results of a nationwide survey investigating the effectiveness and state of practice of using methacrylate as a crack and surface sealer. Although a wide range of application temperatures was reported in the literature, application temperatures between 7°C and 29°C are generally recommended. Cracks should be sealed as soon as possible to ensure that chloride concentrations do not reach the corrosion threshold value. For old decks, careful attention should be paid to the preparation method and cleanliness of both the deck surface and cracks. For areas not subjected to deicing chemicals and chloride-laden environments, HMWM can nearly restore the full bond and flexural strength if the cracks are narrow and free of contaminants.