New product announcements: 10/28/2009 Noncorrosive Sealant: Works On Many Materials The Chem-Calk 1250 Series is a high-performance oxime-neutral silicone sealant with high UV resistance and rapid curing. The sealant features a noncorrosive, low-odor formulation that can be applied to a wide range of substrates without compromising them, including masonry, metal, plastic and wood. The sealant can be used in both indoor and outdoor settings and is able to retain its elastomeric properties in temperatures ranging from -61°F to 348°F. Bostik; 888-592-8558; www.bostik-us.com Fireproofing: Expansion Joint Seal Is Fire-Rated EMSHIELD WFR2, or Wall, Fire-Rated 2-Hours, is a fire-rated primary seal for
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.