Abstract
Recently, researchers have made effective use of Black Space diagrams to model stiffness and relaxation changes relating to non-load-associated cracking. A Black Space-based approach to detecting cracking susceptibility is the Glover-Rowe (G-R) parameter, which requires complex modulus and phase angle at a particular temperature-frequency combination. This parameter is being evaluated as a replacement for low-temperature Superpave binder criteria. Primary objectives are to validate the G-R approach for binders with laboratory and field performance measurements; develop an indicator parameter for low-temperature cracking of mixtures using a combination of material properties; and develop alternate approaches to study mixture performance in Black Space. The G-R intermediate-temperature parameter shows mixed results with Black Space location for sections with thermal cracking. The G-R low-temperature parameter is used to determine a critical cracking temperature that agrees with Superpave binder specification. A preliminary evaluation of a mixture-based Black Space parameter is included.