The University of Illinois at Urbana-Champaign, in collaboration with the Virginia Transportation Research Council and nine states, will conduct a Phase II project TPF-5(225), to validate and implement the recently developed Performance-Based Guidelines for the Selection of Hot-Poured Crack Sealants. This major national study aims to validate the developed laboratory tests, to determine the thresholds using a more diverse array of field performance data, and to implement crack sealant guidelines for field application including seven testing standards.
Recently, Al-Qadi and his co-workers in collaboration with the National Research Council of Canada developed performance-based guidelines as a systematic procedure to select hot-poured bituminous crack sealants. These guidelines are the outcome of the pool-fund North American Consortium The sponsoring consortium included eleven U.S. state departments of transportation, thirteen Canadian transportation agencies, and industry. The U.S. contribution was made through the pool-fund research project TPF-5(045), with the Virginia Department of Transportation (VDOT)/Virginia Transportation Research Council (VTRC) being the lead state. The work proposed an innovative approach to identify hot-poured bituminous-based sealant acceptance for a specific location based on environmental conditions, “Sealant Grade” (SG) system. Several tests for sealant characterization and again over a wide-range of temperature were developed including the following tests that have been adopted as AASHTO provisional standards:
1) TP 85-10 Apparent Viscosity of Hot-Poured Bituminous Crack Sealant Using Brookfield Rotational Viscometer RV Series Instrument
2) TP 86-10 Accelerated Aging of Bituminous Sealants and Fillers with a Vacuum Oven
3) TP 87-10 Measure Low Temperature Flexural Creep Stiffness of Bituminous Sealants and Fillers by Bending Beam Rheometer (BBR)
4) TP 88-10 Evaluation of the Low-Temperature Tensile Property of Bituminous Sealants by Direct Tension Test
5) TP 89-10 Measuring Adhesion of Hot-Poured Crack Sealant Using Direct Adhesion Tester
6) TP 90-10 Measuring Interfacial Fracture Energy of Hot-Poured Crack Sealant Using a Blister Test
One may refer to the summary report as well as another detailed report published on the ICT website (ICT Publicationsp).
As an outcome of the TPF-5(045) study preliminary threshold(s) for each test were established based on extensive laboratory testing and limited field data. Laboratory testing development is being continued and field validation is being conducted under the new project to validate and to fine-tune the threshold values.
For more information visit http://www.pooledfund.org/projectdetails.asp?id=453&status=4