The perfect storm that sent liquid asphalt prices through the roof in the summer of 2008, creating angst amid road builders and public-sector officials alike, has given way to an outlook for 2010 of stable prices, lower demand levels and less volatility going forward. Since their peak in summer 2008, liquid asphalt prices—the key factor in the cost of asphalt paving mixes—have dropped by nearly half this summer, sources say. The nationwide squeeze on road funding and the general lydown economy will likely keep prices moderate and reduce volatility in asphalt paving mixes through 2010. Source: McGraw-Hill Platts. Liquid Asphalt
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.