SUMMARY

RemBind presented advances in stabilizing PFAS-impacted asphalt and concrete, demonstrating that the same sorbent technology proven in soil can be adapted to unlock reclaimed asphalt pavement (RAP) and crushed concrete for unrestricted onsite reuse, avoiding landfill disposal while maintaining material performance.

• PFAS stabilization (immobilization) uses sorbents to lock contaminants in place and prevent leaching; it does not reduce total PFAS mass, and can incorporate cement to further reduce leaching and improve strength.
• RemBind is a patented blend of carbons, clays, and oxyhydroxides that binds PFAS through a “mixed mode” mechanism — the carbon component grips the hydrophobic backbone while the clay component electrostatically captures the charged head group (e.g. sulfonate in PFOS).
• Over 1 million tonnes of soil have been treated worldwide since 2014, achieving 95–99% reductions in PFAS leachability at 1–3% addition rates, with long-term stability proven using US EPA LEAF methods and published in peer-reviewed literature.
• PFAS-impacted asphalt and concrete present added complexity versus soil, including high pH, matrix interferences, and variable particle sizes, and recycling untreated RAP risks PFAS volatilization during hot-mix processing and leaching from the new pavement.
• In an asphalt trial with Fulton Hogan, milled RAP spiked to 66 mg/kg PFAS (leaching at 2,784 µg/L) was treated with 2% RemBind sorbent; removal reached 99.98% for PFOS and over 99.9% for several other species, at both ambient and 140°C (hot-mix) conditions.
• The treated asphalt monoliths achieved a Resilient Modulus of 4,993 MPa, exceeding the standard asphalt plant mix benchmark, confirming the treatment does not compromise pavement performance.
• For concrete, three commercial pathways were developed based on particle size: standard RemBind stabilization for material under 10 mm, a RemBind + additives + RAP aggregate route for 10–25 mm material, and a RemBind + polymer coating for 25–100 mm fragments (the latter two pending patent applications).
• A 2026 case study showed concrete crushed onsite to under 10 mm and mixed with RemBind at 1–2% w/w reduced PFAS leachability by 98–99% via TCLP testing, securing regulatory approval for field implementation at a 2% addition rate, with treated material reused onsite at 2 m depth.
• Independent peer-reviewed testing (Kabiri et al., 2021) confirms RemBind remains stable and resistant to PFAS desorption across a pH range of 2–12, including pH 10, which is typical of fresh concrete leachate.
• The technology offers a circular economy approach allowing soil, asphalt, and concrete at the same PFAS-impacted site to be stabilized and reused with one sorbent system, reducing reliance on virgin fill materials, avoiding costly landfill disposal, and lowering carbon footprint.