Pavement Testing Facility

Purpose: The Pavement Testing Facility uses rapid pavement testing of full-scale structures to develop and verify new specifications, designs, and test procedures for rigid and flexible pavements. The facility is used by pavement and highway research engineers to evaluate the durability of both new and existing pavement materials and to help develop smoother and more cost–effective highway systems.

Laboratory Description: The facility simulates truck traffic with controlled loading and pavement temperatures. In only a few months, the facility’s loading machines can apply wheel loads corresponding to many years of service and collect the corresponding pavement distress and performance data. Two machines allow simultaneous testing of two pavement lanes under the same ambient temperature and moisture conditions or at the same pavement age.

Laboratory Capabilities: Thirty-five thousand simulated axle passes can be applied per week, and the wheel load can be varied from 33 kN (7,500 lb) representing a light truck to 84 kN (19,000 lb) for simulating a heavily loaded vehicle. The wheels feature programmable lateral wander, and the tire configurations can be interchanged, such as standard dual or super single. The wheel speed can be varied up to 18 km/hr (11 mi/hr). Radiant heaters are used to control the pavement temperature; temperatures as high at 74 °C can be generated to accelerate asphalt rutting and during the fall, spring, and winter, the heaters are used to maintain an intermediate ambient temperature. Each full-scale test lane is 50 m by 4 m (165 feet by 14 feet), which can be further subdivided into 4 sites for a total of 48 test locations on the facility grounds. A supplemental three-cell test pit and reaction frame allows the water table to be controlled with additional flexibility in testing for unbound pavement layers and other pavement structures.

Laboratory Equipment: Twelve full-scale pavement test lanes, two Accelerated Loading Facility machines, a falling weight deflectometer and portable seismic pavement analyzer (PSPA) used for nondestructive pavement testing, dynamic cone penetrometer, instruments, sensors and equipment to measure load-associated pavement response (stress, strain, and deformation), pavement performance distress measurements (rut depth, cracking severity and extent, and roughness), and environmental effects (temperature and moisture), which include a state-of-the-art multichannel data acquisition system to collect pavement instrumentation response data, electronic temperature control and data acquisition to show and record pavement temperatures at various locations in real time, a semiautomatic laser surface profiler to measure both transverse and longitudinal pavement surface profiles, a layer deformation measuring system to monitor vertical compressive strain and rutting in each layer of pavement, computer workstations and software to perform advanced pavement analysis and material modeling, as well as mechanistic design, and relational databases developed to provide customers with a variety of data from pavement-testing experiments, especially pavement response and performance data.