Winter 2017-18

KNOWLEDGE BASE ® esign interloc WINTER 2018 InterlockDesign.org 19 A key to successfully using deicing materials on segmental concrete paving (or any concrete) is using only as much as needed to do the job. This will maximize benefits while minimizing concrete and surrounding environment damage. The following guidelines can help limit the exposure of deicing chemicals while maintaining a safer environment: y y Apply sand first to increase traction, then apply deicers as needed. Sand should not be applied to permeable interlocking concrete pavements. y y Rock salt (sodium chloride or NaCl) is the least damaging to concrete materials and should be used whenever possible. y y If a more effective, quicker acting deicer is necessary, consider the judicial use of calcium chloride. y y The use of magnesium chloride and CMA is not recommended because they can chemically degrade all types of concrete, significantly increasing potential damage. The potential for damage from CMA increases with the amount of magnesium in the formulation. y y Do not over-apply deicing chemicals; follow the recommended dosage. y y Do not use deicing chemicals in place of snow removal, but reserve them for melting ice formed by freezing precipitation or freezing snow melt. Guidelines for Limiting Deicing Chemical Exposure y y Once loosened, snow, ice, and excess deicing salts should be promptly removed by plow or shovel to avoid an increasing concentration of deicing chemical(s). y y Protect vegetation and metal from contact with deicing chemicals as most can impair vegetation and corrode metals. In addition, use ICPI-recommended jointing and bedding sand materials to minimize water penetration into the pavers. This can also help reduce deicers from entering and accumulating in the jointing and bedding sand that may eventually degrade the pavers. ICPI also recommends adequate pavement slopes (typically a minimum of 2%) to facilitate surface water drainage and help remove deicing materials. While not essential, reduction of water entering jointing sand can be further enhanced with joint sand stabilization materials and/or sealers. The following chart compares common deicing chemicals with respect to their effective temperature, plus their impact on the potential freeze-thaw degradation and on chemical degradation of the concrete Knowledge Base continued from page 18