Factors affecting binder properties between production and construction

The majority of U.S. departments of transportation (DOT) maintain quality assurance (QA) programs that require asphalt binder testing to verify grade compliance according to Superpave performance grade (PG) specifications. In Texas the binder is tested immediately after binder production, although the goal of QA is to ensure that the binder specified is used during construction. Between production and construction, the material is stored and transferred multiple times before it reaches the construction site or hot mix asphalt (HMA) plant. During this journey, binder properties may change due to many factors and these changes may have a negative impact on performance. To evaluate which factors are detrimental, a laboratory testing program was conducted to simulate the effects of storage time, storage temperature, contamination, and modification on the dynamic shear rheometer (DSR) performance parameter G*/sin[delta] after rolling thin film oven (RTFO) aging. A statistical analysis was performed, and the results indicated that all factors included in the simulation were significant. Results, conclusions, and general recommendations are provided to improve the current TxDOT QA program. DOI: 10.1061/(ASCE)0899-1561(2005)17:1(89) CE Database subject headings: Aging; Asphalt pavements; Binders, materials; Contamination; Quality control; Road construction; Storage tanks; Temperature effects; Texas.