Title: Evaluation of Dampproofing Performance and Effective Penetration Depth of Silane Sealers in Concrete
Author(s): P. D. Carter
Publication: Symposium Paper
Appears on pages(s): 95-118
Keywords: bridge decks; chlorides; corrosion; parking facilities; penetration tests; permeability; sealers; silane; waterproofing; Structural Research
Penetrating concrete sealers are often used on highway bridges and parking structures to slow down the rate of chloride-related reinforcing steel corrosion, thereby extending service life and reducing life-cycle structure costs. Silane sealers are the type most commonly used and are evaluated. Presents data on the effects of several variables on the resultant dampproofing performance and penetration depth. These variables include substrate conditions that influence sealer penetration depth, total active silane content, and the effects of subsequent silane retreatments. The Alberta Transportation and Utilities (AT&U) sealer evaluation methods that are used to measure dampproofing performance and effective penetration depth are described. Data show that the permeability of modern high-quality, low-permeability concretes can be significantly improved by silane sealers, whereas porous, high water-cement ratio concretes may be more effectively sealed by barrier coatings that seal the surface of porous concrete and do not penetrate. The concept and method of measuring the effective penetration depth is explained. Increasing the concentration of the active silane in a penetrating sealer improves both the effective penetration depth and the overall dampproofing performance on modern, good-quality concrete. Periodic resealing of the concrete with lower concentrations of silane results in a similar effect. Resealing can be successfully done through the previously sealed surface without expensive methods of surface preparation as long as the surfaces are clean and dry.