Asphalt Materials Laboratory
Burns Cooley Dennis, Inc. (BCD) operates AASHTO-accredited CMET laboratories that maintain all necessary equipment required for the complete analysis of flexible pavement materials. This includes the equipment necessary for accomplishing the characterization of base, subbase, and asphalt concrete materials. BCD has the capabilities to conduct numerous aggregate property tests including: washed gradations, unit weight and voids, Los Angeles Abrasion, sodium and magnesium sulfate soundness, fine aggregate angularity, coarse aggregate angularity, flat and elongated particles, permeability, shear strength, resilient modulus, specific gravity and absorptions.
BCD has the capabilities for the complete rheological characterization of asphalt binders. We maintain and operate the equipment required to conduct Superpave performance gradings for asphalt binders. For the aging of asphalt binders, BCD utilizes a James Cox & Sons rolling thin film oven and a Prentex pressure aging vessel. For characterizing the high and intermediate temperatures of binders, BCD operates a TAInstruments dynamic shear rheometer. For low temperature properties, we utilize a Cannon Instrument Company bending beam rheometer. BCD can also characterize asphalt binders by more conventional methods like absolute viscosity and penetration testing.
The CMET laboratory can also fully characterize hot mix asphalt mixtures, from mix design through forensic type investigations. BCD is experienced in conducting both Marshall and Superpave mix designs. For forensic investigations, we have the capabilities to determine asphalt binder contents using either the Barnstead-Thermolyne ignition oven or by solvent extractions. When using solvent extractions, we can also recover asphalt binders using the rotovapor method.
BCD has the ability to conduct all manner of pavement materials characterization testing. BCD has the equipment to conduct all testing associated with the upcoming 2002 AASHTO Pavement Design Guide. BCD maintains an Interlaken Soil & Asphalt Test System that permits application of dynamic, fatigue, and creep type loadings with the ability to measure small strains. With this equipment, BCD has the capabilities to conduct the following tests related to the new Pavement Design Guide:
- AASHTO TP8, Flexural Fatigue of Asphalt Beams
- AASHTO TP9, Creep Compliance Test Method
- AASHTO TP31, Determining Resilient Modulus in Indirect Tension
- ASTM D3497, Dynamic Modulus of Asphalt Mixtures
- ASTM D4123, Determining Resilient Modulus in Indirect Tension
- AASHTO TP46, Resilient Modulus of Base and Subbase Materials (or the new harmonized MR test recommended as part of NCHRP 1-28A)
The test equipment utilized for pavement materials characterization can also be used to conduct the Simple Performance Tests recommended during the NCHRP 9-19 Project which include: Dynamic Modulus, repeated load permanent deformation test (Flow Number) and static creep test (Flow Time).