Pavement Testing & Facilities

PRP is the largest and most active independent pavement lab in the New York/New Jersey metro region.

PRP has more than 18,000 square feet dedicated laboratory space, including the renowned Rutgers Asphalt Pavement Laboratory (RAPL), with more than $3 million in permanent equipment and set-ups.

Asphalt Mixture Performance Tester (AMPT)

The AMPT is designed to determine dynamic modulus of asphalt core samples. Dynamic modulus is simply the stiffness of the asphalt core under a variety of temperatures and loading scenarios. AMPT is a key component in evaluating the quality of asphalt performance samples. Currently, the Mechanistic-Empirical Pavement Design Guide relies on dynamic modulus as a basis for design criteria. The AMPT is also calibrated to conduct repeated load testing and static creep testing, which determines permanent deformation properties.

Asphalt Pavement Analyzer (APA)

The APA is designed to simulate traffic loading created by vehicle wheels. A moving wheel load atop a pressurized rubber hose replicates the repeated loads a pavement will see during its daily cycle. The rate and pressure of the loading is controlled by a dedicated computer, which also acts as data acquisition for the APA. The entire chamber is also environmentally controlled so rutting potential can be measured for an array of conditions. Engineers can determine the rutting potential of specific asphalt mixtures using the APA as a comparative tool.

Flexural Beam Fatigue Device

This device is used to determine fatigue life and fatigue energy of compacted HMA samples. The system is designed to conduct AASHTO T321, Standard Test Method for Determining the Fatigue Life of Compacted Hot-Mix Asphalt (HMA) Subjected to Repeated Flexural Bending. However, the system is designed also to provide a wide range of loading types (haversine, sinusoidal, double-hump, triple-hump) for both stress and strain controlled modes. The device is enclosed in an environmental chamber to provide a wide range of potential temperature applications (-10 degrees C to 60 degrees C).

Asphalt Mix Compactors

RAPL has four different HMA compactors. Two gyratory compactors, used for the Superpave design method, use a kneading-type of compaction motion to produce asphalt samples. The molds compact a sample 150 millimeters in diameter and up to 200 millimeters high. The ram pressure applied to the sample is 600 kilopascal, with an internal angle of gyration of 1.16 degrees.

RAPL also has a vibratory compactor, which creates either round (pill) or brick compact asphalt samples using a vibrating plate that applies vertical force. The vibratory compactor is typically used when compacting brick samples for testing flexural beam fatigue specimens, but it can also be used to produce brick specimens for the Asphalt Pavement Analyzer.

The fourth compactor at RAPL is the Marshall compactor. This compactor uses an impact type of compaction method: A blow of 10 pounds at a drop of 18 inches is applied to the asphalt mix. The number of blows depends on the type of asphalt mix to be compacted.

Indirect Tensile Tester (IDT)

The IDT device is used to determine the low temperature creep compliance and low temperature indirect tensile strength of HMA specimens. These material properties are not only used to characterize the low temperature cracking properties of different mixes, but also used as direct input parameters for the Mechanistic Empirical Pavement Design Guide.

NCAT Ignition Oven

The ignition oven is used to determine the asphalt binder content of hot mix asphalt by “burn off.” HMA material is placed in a wire cage and inserted into the oven. The difference between the starting weight and the final weight is the amount of asphalt binder that has been “burned off.” With that value, asphalt content can be determined and compared with design specifications.

Pine Instruments Compression Device for Marshall Stability and Flow

RAPL’s compression machine designed by Pine Instruments is used to determine the stability and flow properties of Marshall samples [http://www.asphaltwa.com/wapa_web/modules/05_mix_design/05_marshall.htm]. The device is capable of testing either 4- or 6-inch diameter samples. Both the stability (maximum compressive strength) and the flow (deformation where the HMA reached the maximum compressive strength) are used as control points in the Marshall design process.

Overlay Tester

The Texas Transportation Institute Overlay Tester is a relatively new test method that simulates the expansion and contraction movements that occur in the joint/crack vicinity of PCC pavements. Although this test procedure is essentially a fatigue-type test, it currently represents the best method to truly simulate horizontal joint movements of PCC pavements in the laboratory.

Superpave Shear Tester (SST)

The SST is used to determine the rutting susceptibility, creep properties, and low strain stiffness properties on HMA mixtures in the shear mode. The bi-axial loading system allows for the simultaneous vertical and shear loading to model in-situ loading conditions. Testing with the device is conducted in accordance with AAHTO T320, Determining Permanent Shear Strain and Stiffness of Asphalt Mixtures Using the Superpave Shear Tester (SST).