Polymer-Impregnated Concrete: Field Studies

The principles developed in the laboratory for polymer impregnation of concrete to depths below the top layer of steel reinforcing rods were applied to the impregnation of large concrete slabs and a bridge deck. The concrete slabs and bridge deck were dried thoroughly using a propane torch assembly (temperature at surface 700°F or 372°C, at a 4-in. (100-mm) depth 250°F or 121°C) impregnated with a 16-in.(410-mm) ethylene film, and polymerized for a 16-in. (410-mm) pressure impregnator at 15psi-80psi (104kN/m²-552kN/m²), wrapped or covered with a polyethylene film, and polymerized for 5hr-8hr using steam from a pressure cooker. The monomer was a 90:10 methyl methacrylate-trimethylolpropane trimethaacrylate mixture containing 0.5% azobisisobutyronitrile intiator. The slabs were impregnated to their full 6-in. (150-mm) thickness, the bridge deck to a depth of at least 5 in. (125 mm). The polymer-impregnated slabs show increased compressive and split-tensile strengths, decreased water absorption, and improved resistance to corrosion, freeze-thaw cycling, abrasion, and acid-etching. The polymer-impregnated bridge deck shows decreased water absorption and improved resistance to acid-etching.