Asphalt Mixture Testing Laboratory

The TTI Asphalt Mixture Testing Laboratory has a full range of equipment needed for sample preparation and evaluation. The lab has standard capabilities for assessing asphalt mixture characteristics (such as stability and skid resistance) and asphalt cement properties (including viscosity, softening point, and flash point). TTI also has the capabilities for performing the SHRP binder specification tests: bending beam rheometer, dynamic shear rheometer, and Brookfield viscosity. Complete molding and test equipment for Hveem and Marshall testing are available. In addition, a computer-controlled ductility machine enables ductility to be assessed as a function of either rate or force.

The laboratory contains a versatile combination of asphalt compaction devices: three gyrating molding machines, hydraulic and electric-hydraulic kneading compactors, and a European rolling wheel compactor. The latter instrument produces test cores with uniform densities throughout, so deformation behavior is highly realistic. The variety of compaction methods available to TTI researchers enables the generation of asphalt samples that conform to the range of standards of specifications found in the field.

Equipment

Asphalt Pavement Analyzer

The asphalt pavement analyzer evaluates fatigue cracking and rutting susceptibility of asphalt concrete specimens or pavement samples.

Dynamic Shear Rheometer and Bending Beam Tester

In testing asphalt binders, the dynamic shear rheometer and bending beam tester give researchers a master curve of the complete rheological behavior of the binder from plant to pavement.

FISONS Element Analyzer

FISONS measures the percentage of carbon, hydrogen, nitrogen, sulphur, and oxygen in asphalt test samples.

Overlay Tester

Unique to TTI, the overlay tester is used to measure stress and strain for fracture mechanics research and to test new asphalt mixes at very controlled temperatures.

Pressure Aging Vessel

This instrument forces oxygen into asphalt samples at pressures of 300 pounds per square inch (PSI) and high heat to simulate the asphalt aging that would occur in the field over a number of years.