Damping performance of rubberised double chip seals

Abstract

Double chip seals provide skid resistance and durability but offer limited vibration damping. This study evaluated rubberised double chip seals using tire-drop and hammer-impact tests and a unified vibration attenuation coefficient. AC-13 asphalt concrete, single chip seals and two double chip seal structures of different thicknesses were tested. Crumb rubber of 8 and 16 mesh was added to the upper layer at 0–2% by aggregate mass. Rubber incorporation markedly improved damping. For the thicker Type B structure, increasing 16-mesh rubber from 0 to 1.5% raised the attenuation coefficient from 0.365 to 0.549, while further addition produced only marginal gains. Type B achieved about 30% higher attenuation than Type A. Considering damping, aggregate retention, immersed sweep loss, and rutting resistance, Type B with 1.5% 16-mesh rubber was the best-balanced configuration. The two test methods were strongly correlated (R2 ≈ 0.90), confirming the reliability of the proposed evaluation approach.