Understanding the Chemical & Mechanical Performance of Snow & Ice Control Agents on Porous or Permeable Pavement

The objectives of this research are to identify the primary chemical and mechanical interactions that occur when deicers are applied to textured or porous pavements before, during and after a winter storm to determine optimal winter maintenance strategies and application rates for treating these types of pavements.

Winter maintenance field personnel and researchers show mixed recommendations regarding snow and ice prevention and removal on porous pavements. Field personnel in some areas of the United States have indicated a need for higher deicer application rates on porous asphalts to obtain an adequate level of service as compared to traditional dense-graded pavements. These observations are supported in NCHRP Report 526 where it is stated that heavily textured pavement surfaces (e.g., open-graded, gap-graded, and porous fiction courses) require an unspecified increase in chemical application rates. Research conducted at MSU by WTI researchers demonstrated that increased efforts in removing snow and ice from more porous surfaces (e.g., porous pavements) is a result of a mechanical occurrence called “keying”. However, other researchers have reported a reduction in salt loads needed for winter maintenance on porous asphalts compared to impermeable asphalts. Research conducted in the Minneapolis–St. Paul area supports these observations by reporting porous surfaces generally restrict re-freeze and promote snow melt. Given that there is contradictory evidence of the effect of textured and porous pavements on current winter maintenance practices, there is a need for research to determine optimal winter maintenance strategies and application rates for treating porous pavements. This project uses a systematic approach including a literature review, interviews of winter maintenance personnel, lab tests, and analysis to develop best practices.