Hydrated lime as the anti-aging bitumen agent

Abstract

In 1999, during rebuilding and modernization of the one of the main streets in Kielce (Poland) it has been placed SMA wearing coarse layer with the hydrated lime. SMA mixture contained 6.2% of D70 bitumen (currently 50/70) and 4% SBS polymer labeled as Kraton 1101 CM. Hydrated lime was dosed into SMA mixture to replace 30% of filler mass. Pavement surface condition after 12 years of service life was very good. In 2011 bitumen, extracted from SMA, tests were made. The tests covered bitumen samples which contained the fatty amine and the hydrated lime as a adhesive agent. Bitumen samples were obtained from SMA wearing course layer at the site of the rut and out of the rut. On the basis of the rheological properties the recovered binder with hydrated lime had a positive effect on reducing aging process of bitumen 50/70 modified with SBS polymer in SMA mixture giving the increase in resistance to the water and frost effect.