Optimization of Concrete Drying Temperature for Monomer Impregnation

The optimum drying temperature of concrete prior to monomer impregnation was investigated. Mortar cubes were cast, dried at different temperatures between room temperature and 316°C (600°F), and impregnated with monomer and polymerized in situ. The cubes were then vacuum-saturated and their resistivities were measured. The cubes were cut and dried to 104°C (220°F), and the influence of drying temperature on the degree of impregnation was evaluated using a mercury porosimeter and a scanning electron microscope-energy dispersive spectroscope. Companion cubes were subjected to ponding-drying cycles in a sodium chloride solution, and the ingress of chloride was determined from powdered samples. Results were used to optimize the drying temperature of concrete for monomer impregnation. The results demonstrated that monomer impregnation of concrete to a desired depth can be achieved at a lower temperature than previously believed.