Google Maps measures and maps roads, and department of transportation workers measure and map the subsurface quality of those roads. One company’s advance in computing asphalt-pavement density data on-site claims to make DOT workers’ jobs easier.
“We have developed … ground-penetrating-radar [GPR] quality-assurance software that can automatically process radar data on-site,” says Kenneth Maser, president of Infrasense Inc., Arlington, Mass. “It covers the entire paved area instead of taking core samples.”
Infrasense and other firms use GPR to image the subsurface of pavement, measuring for thickness, density and base moisture by using radar pulses. Maser uses a low-frequency antenna called a ground coupled, held very near the ground for deeper penetration and a higher frequency antenna which is positioned one and a half feet up from the ground, for higher resolution of the pavement layers, he says.
Infrasense’s software, called GPRQA, displays information from the radars and plots it in a more readable way, says Maser. It automates the processing of the GPR system's data, which usually requires office processing after data collection.
“Maser’s software certainly can make things easier in terms of getting high- and low-depth constancy,” says Shongtao Dai, research operations engineer at the Minnesota DOT. “We’re using it on a few projects now and getting good results, but we’re still taking core samples and evaluating the product.”
Two years before MinnDOT used the software, Maser extended the software's capabilities after working with Florida's department of transportation, he says. "One improvement added [to MinnDOT's] version is the incorporation of GPS coordinates in the results," says Maser. "We also streamlined some of the data entry so that it is faster and easier.”
The software does not require any prior experience with GPR, which is one major plus, says Maser.
Corrections to software name and software availablilty made on 10/19/12.
