This report describes a series of laboratory and field studies undertaken to demonstrate the feasibility of polymer impregnation of concrete bridge decks from the upper surface to depths that will encase the top layer of reinforcement to arrest or prevent spall- and pothole-causing corrosive action. Deep impregnation of typical salt-contaminated concrete was achieved in the laboratory when the concrete was brought to a bone-dry condition. Impregnation was found to arrest the corrosion of reinforcing steel, virtually eliminate freeze-thaw damage, and substantially increase the resistance of the concrete to chemical attack. Water absorption and loss by abrasion were reduced several-fold. Using gas-fired infrared heaters for drying the concrete, moderate pressure to aid monomer impregnation, and hot water to achieve polymerisation, deep penetration (up to 4 in. (10 cm)) was achieved on two bridge decks, one of which was heavily salt-contaminated. The equipment and techniques developed for the field demonstration are believed to be of a nature to permit scaling up for practical use. The research employed a methyl methacrylate mixture. (Author/publisher)
Abstract