The first concrete street built in the United States was an 8-foot wide strip of Main Street completed in 1891 in Bellefontaine, Ohio. Local residents were so pleased with the artificial stone road, scored to provide better footing for horses, that much of downtown Bellefontaine was paved with concrete.
Many municipalities today choose concrete pavement because of its reputation for long-term serviceability and a sense that it provides better value for the investment. Today, concrete has become the least expensive alternative for new construction on a first-cost basis in addition to maintenance costs being generally lower. Aesthetic considerations, coupled with concrete's ability to reflect light and heat, have made it the paving material of choice for many cities. Because of its light color, concrete can mitigate the urban heat island effect, reducing smog and promoting better air quality. It also reflects from 33 to 50 percent more light than asphalt so cities can achieve the same street lighting standard, with a lower initial investment in lighting fixtures and equipment, and, as well, can sustain considerably lower long-term energy costs.
Fast-track paving techniques, in which the use of a high-early-strength concrete mix allows the road to reopen in as few as 12 hours, have increased the attractiveness of concrete for city street paving because of the inconvenience of closing busy urban routes.
Concrete overlays, both bonded and unbonded, provide cost effective rehabilitation of aging urban asphalt paving. The process involves overlaying a stratum of concrete on top of an asphalt road that needs rehabilitation because of rutting, shoving, or other types of deterioration. While unbonded concrete overlays require a thickness of five to seven inches on secondary roads, and from eight to 12 inches on primary roads, bonded concrete overlays require a thickness of only two to four inches. View or download a fact sheet on Concrete Overlays.
Test results indicate that the thinner layer of high-strength, fiber-reinforced concrete performs adequately because the concrete creates a structural bond with the prepared surface of the asphalt below. It becomes, in essence, a composite pavement. Joints are spaced closer together than with conventional concrete pavement, usually about 12- to 18-inches apart for each inch of concrete depth. This helps ensure the bond between the concrete and asphalt below, especially in freeze/thaw conditions where differential movement of the two materials would be anticipated. Although further long-term research needs to be done on the technology, bonded concrete overlays could be valuable for rehabilitating high-traffic city streets and intersections.