Comparison of permeable friction course mixtures fabricated using asphalt rubber and performance-grade asphalt binders

Permeable friction course mixtures (PFC) are special hot mix asphalt (HMA) mixtures that are designed to improve motorist safety and reduce traffic noise (i.e., tire–pavement noise). In terms of pavement structural design and construction, PFC mixtures are typically used as the surfacing course layer where in addition to improving the skid resistance, also serve as the surface drainage layer. This paper compares PFC mixtures designed and fabricated using performance grade (PG) and asphalt rubber (AR) asphalt-binders (or asphalts). The experimental design included assessment of total air voids (AV) content, durability, drainability, stone-on-stone contact, and internal structure of the PFC mixtures fabricated using both AR and PG asphalts; denoted herein as AR–PFC and PG–PFC mixtures, respectively. The analysis conducted provided evidence of differences between AR–PFC and PG–PFC mixtures that suggest the need for differentiation and refinement of the existing specifications to consider these mixtures as independent materials. Future research should, therefore, focus on defining particular specifications for mix design and control for AR–PFC and PG-PFC mixtures.

► Asphalt rubber (AR) and performance grade (PG) asphalts are used to fabricate PFC mixes.
► Differences were identified for PFC mixes fabricated using AR- and PG-asphalts.
► These differences include durability and functionality aspects of PFC mixes.
► Refinement of existing specifications for both AR- and PG-mixes is suggested.
► These AR- and PG-mixes should be treated as independent materials.