Iowa’s PG Binder Grades and Traffic Design Levels Undergo a Transformation
In October of 2016, the nomenclature for the asphalt cement
binder grading system will be changed to accommodate the Mulitple Stress Creep
Recovery (MSCR) test. During this transition, the Iowa DOT has seized on the
opportunity to address Iowa’s numerous pavement design levels and the need to
lower the “bottom end” binder grade across the state. The MSCR binder
classification and the traffic design guides will utilize the “SHOVE” acronym.
“S” = Standard, “H” = Heavy, “V” = Very Heavy, “E” = Extremely Heavy. In
addition, Iowa will be divided into a “Southern” and “Northern” districts. The
Southern district will require a PG 58-28S as the standard grade of asphalt and
the Northern district will require a PG 58-34S. An easy reference guide is
provided below and printed copies will also be available through the APAI. Dr.
Scott Schram, IDOT Pavement Management Engineer, has created an excellent
webinar that can be viewed by clicking here. If
you have questions, or would like to schedule a meeting with the APAI, please
contact our offices at 515-233-0015 or email at [email protected].
Click here for easy reference guide.