Nanotechnology for binders of asphalt mixtures

Abstract

Clay additives in bituminous mixtures were investigated. Two different organic Montmorillonite nano clays showed completely different improvements when added to bitumen. One of the investigated nano clays showed a real ageing improvement. The viscosity of the binder was not changed compared to the original 70/100 bitumen when 6% by mass was added. But the ageing characteristics were improved both in short term and in long term ageing. An important application for this type of improvement could be in porous asphalt. The other clay changed the viscosity in a pronounced way and therefore showed potential for other applications like dense asphalt or as an additive to prevent binder drainage during transportation. Several investigations claimed ageing improvements by adding polymers, hydrated lime, etc. It is shown that some of these improvements are not due to the claimed ageing characteristics but might be due to the influence on viscosity of these additives. For the covering abstract see ITRD E157233