Jack Wilson admits it: He welcomes the rising price of asphalt. It’s not a concrete bias—he is a 40-year contracting veteran who worked impartially with both asphalt and concrete. But now that asphalt milling and repaving is more expensive, he believes the time has finally come for his asphalt overlay invention to gain a wide audience. Photo: Polycon Proprietary overlay creates a protective seal over existing asphalt, eliminating need for constant milling Related Links: America May Gain from Materials Designed To Stretch Your Stimulus Dollars Packing in Particles Yields 100-Year Concrete Mixes Long-Life Composite Bar Receives Second Chance Cylindrical Solar
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.