Porous Pavement

Porous Pavements

Pavements are the most ubiquitous of all man-made structures, and they have an enormous impact on environmental quality. They are responsible for hydrocarbon pollutants, excess runoff, groundwater decline and the resulting local water shortages, temperature increases in the urban "heat island," and for the ability of trees to extend their roots in

Porous Pavement for Control of Highway Run-off

In 1986, the Arizona Department of Transportation (ADOT) constructed a 3500- foot porous pavement experimental section on SR-87 in the Phoenix metropolitan area. The objectives of this project were to determine the constructibility and subsequent performance of porous pavement as a drainage system and pavement structure in an urban area and a desert environment. The porous pavement test section has performed satisfactorily for five years. Although a slight decrease in the infiltration rate has occurred, both the infiltration rate and the storage capacity are above the design values. Visual observation during storm events has shown that the surface of the porous pavement section does not include sheet flow. This provides a marked difference in stripe delineation and pavement glare during night time inclement weather driving when compared to conventional pavement. However, Mu-meter meter skid test results for the porous pavement section are comparable to those of conventional pavements (control). Material tests conducted on the pavement components indicate that the Marshall stability, resilient modulus, and asphalt cement viscosity of the open graded asphalt concrete have increased with time. No cracking or significant surface deformation has occurred during the five years of service. Annual FWD testing was conducted to establish the changes in layer properties. To date, little change has occurred in the layer moduli except for the open graded subbase whose modulus has decreased with time. This phenomenon is unexplained at present. No unusual presence of moisture was detected in any layer of the pavement system. The subgrade moisture content has achieved equilibrium at less than the optimum content determined during the design process.

Porous Asphalt Pavements