When state highway authorities in two US jurisdictions needed subsurface pavement construction information recently, Fugro deployed its specialised ARAN data collection vehicles to survey their road networks.
The Louisiana Department of Transportation and Development needed to make a case for federal funding to repair highway damage caused by Hurricane Katrina whilst in Virginia, the Department of Transportation had a requirement for more accurate information for its Pavement Management System (PMS). Here variances in recent load-bearing tests had raised questions about the reliability of existing data.
Much of North America’s road network is decades old. Highways have been widened, connected and resurfaced repeatedly and construction and repair records are often unavailable. Compared to coring, Ground Penetrating Radar (GPR) offers a more cost-effective, non-destructive and non-disruptive method of data collection.
For both government departments Fugro’s ARAN vehicles collected pavement data and conducted the pavement management survey in a single pass. All engineered layers of pavement were scanned – up to 40 inches (1 metre) deep – and sample rates of up to one scan per 20 inches (0.5 metre) at 50 miles (80 kilometres) per hour were achieved. Data were delivered in PMS-compatible formats for use with client systems and reports provided details of layer thickness values within construction segments. The survey also enabled Fugro to direct the requirement for and the location of core samples.