ORIGINAL ARTICLE Evaluation of surface sealers for concrete hydraulic structures exposed to low temperatures Jahangir Mirza • Charles Abesque • Marc-Andre ´ Be ´rube ´ Received: 3 September 2009 / Accepted: 5 April 2010 / Published online: 22 May 2010 Ó RILEM 2010 Abstract Many hydraulic structures exhibit down- stream cracks and surface degradation due to porous and non air-entrained concrete cast only a few decades ago, wetting–drying and freezing–thawing cycles. These degradations could be prevented by minimizing surface saturation and water infiltration by sealing the concrete surface. Many different types of sealers, such as silanes, siloxanes, boiled linseed oil, epoxies, urethanes and cement-based products, are presently available on the market. However, despite their ready availability, very few or no laboratory or field evalu- ations have ever been undertaken to evaluate their effectiveness, specifically for hydraulic structures exposed to extremely low temperatures. Consequently, 60 different surface sealers were selected for labora- tory evaluation, aimed at minimizing water or moisture infiltration, and to extend the service life of hydraulic structures, besides reducing the harmful effects asso- ciated with concrete surface deterioration. The tests carried out on these sealers comprised reduction of absorption and evaporation capacity, durability under freezing–thawing and wetting–drying cycles, acid rain, UV radiation, effect of various parameters, such as concrete water:cement ratio (W/C), sealers application temperature, pH variation, presence of hydrostatic pressure, etc. Preliminary data showed that silanes and siloxanes exhibited satisfactory results, however, prod- ucts from the same family yielded variable results. This paper summarizes a part of a large study on concrete sealers for hydraulic structures in cold climates. Keywords Cold climates  Concrete hydraulic structures  Silanes  Siloxanes  Vapor transmission  Water absorption 1 Introduction Durability of concrete structures is largely related to the severity of their exposure conditions, which at latitudes in Que ´bec (Canada), comprises frequent wetting–drying and freezing–thawing cycles. In addi- tion, concrete used for road surfaces is exposed to abrasion due to traffic and the penetration of snow melt and chloride-ions from de-icing salts that subsequently attack the steel reinforcement, causing future deterioration due to corrosion of the steel reinforcing bars. On the other hand, the concrete used in dams is not exposed to de-icing salts, however, other factors must be taken into consideration. For example, the type of concrete in hydraulic structures is generally less resistant and more porous than that J. Mirza (&) Research Institute of Hydro-Quebec, Varennes, QC, Canada e-mail: mirza@ireq.ca C. Abesque Association des Constructeurs de Routes et Grands Travaux du Que ´bec, Que ´bec City, QC, Canada M.-A. Be ´rube ´ Department of Geology and Geological Engineering, Laval University, Que ´bec City, QC, Canada Materials and Structures (2011) 44:5–12 DOI 10.1617/s11527-010-9604-x