Thin Overlays - State
Types of Thin HMA Surfacings • Dense-graded mixes – Continuously graded, Superpave – High Performance Thin Overlay (HPTO) • Open-graded mixes – 15-22% voids, fibers and polymer or crumb rubber – Used to reduce splash and spray, improve high speed friction and reduce tire noise • Gap-graded systems – SMA and SMAR mixes (9.5mm & 12.5mm) – Ultra-Thin systems (Novachip)