Revision and Further Validation of Surface-Performance Graded Specification for Surface Treatment Binders.

摘要

The design and selection of surface treatment binders in service is currently based on specifications that include tests of emulsion residues or hot-applied asphalt cements at standard temperatures that do not cover the entire range of in service temperatures, measure properties that are not performance-related, and do not consider representative aging conditions for the critical first year. Current specifications for these binders consider properties of the material during both construction and in service, and a wide range of materials can be utilized to meet the current specified properties. A surface performance-graded (SPG) specification for the evaluation and selection of chip seal binders which addressed these shortcomings was developed as part of previous Texas Department of Transportation (TxDOT) and National Cooperative Highway Research Program (NCHRP) research projects. In the current study, the SPG specification was revised and further validated.. This was accomplished by standardizing the emulsion residue recovery method through the evaluation of two warm oven methods, exploring the exclusive use of the dynamic shear rheometer (DSR) for determining performance-related properties, and further field validating the thresholds for these properties. The laboratory and field results were used to revise the SPG specification for surface treatment binders in service. Moreover, the results obtained from the multiple stress creep recovery and DSR frequency sweep tests were compared with field performance to evaluate additional criteria for the specification. This study is limited to producing a revised SPG specification for performance-related properties that address aggregate retention and bleeding in service.