Specialized testing of asphalt cements from various ADOT&PF paving projects.

PDFTech ReportINE/AUTC 15.064000(133)DAsphalt cementAsphalt additivesCracking of asphalt concrete pavementsFatigue crackingStress crackingAlaskaAlaska. Dept. of Transportation and Public FacilitiesHesp, Simon A.M.Alaska University Transportation CenterQueen's University. Dept. of ChemistryUS Transportation CollectionThe Alaska Department of Transportation and Public Facilities (ADOT&PF) sampled five different asphalt cements for specialized testing at Queen\ue2\u20ac\u2122s University inKingston, Ontario. This report documents and discusses the findings. The tested asphalts were: PG 58-34, PG 52-40D, PG 52-40N, PG 58-28, and PG 64-28.Testing results showed that grade losses according to Ontario\ue2\u20ac\u2122s LS-308 Extended Bending Beam Rheometer (EBBR) ranged from 3.4\uc2\ub0C to 6.3\uc2\ub0C. Losses accordingto Ontario\ue2\u20ac\u2122s LS-228 Modified Pressure Aging Vessel (PAV) ranged from 0\uc2\ub0C to 7.3\uc2\ub0C. Grade losses of 3\uc2\ub0C and higher are significant in terms of their ability to reducepavement life cycles. Double-edge-notched tension (DENT) tests according to Ontario\ue2\u20ac\u2122s LS-299 DENT protocol were done on PAV residues. The critical crack tip openingdisplacement (CTOD) was determined and, at 15\uc2\ub0C, it varied from a low of 19 mm for the PG 58-28 to a high of 175 mm for the PG 58-34. The PG 58- 40D showed a CTODof 139 mm, contrasting with the low polymer PG 52-40N at only 36 mm, a nearly four-fold difference. All the results obtained from this specialized testing effort suggestthat these materials will provide significant differences in performance. This report provides recommendations on how to obtain better value for money by implementinga few simple changes to the ADOT&PF asphalt cement specifications