Products 01/26/2011 Rotary Hammers: Lower Vibration Levels Bosch introduced three new Bulldog Rotary Hammers at the World of Concrete in Las Vegas earlier this month which incorporate Bosch’s Active Vibration Control. An air cushion built into the hammer mechanism and dampening elements in the grip area reduce vibration levels. The 11/8-in. RH328VC and RH328VCQ deliver 2.6 lb ft of impact energy, while the 11/4-in. RH432VCQ delivers 3.7 lb ft of impact energy. The hammers have three operational settings: rotary hammer, hammer-only and rotation-only. Bosch Power Tools; 877-267-2499; www.boschtools.com Air Quality Monitor: Simultaneous Logging The AdvancedSense IAQ/HVAC Portable Data Collection Meter
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.