Strength characteristics and durability of epoxy asphalts

Since 2001, the Highways Agency in the UK have been involved in a joint research project on economic evaluation of long life pavements, in collaboration with a number of national institutions under the umbrella of the Organisation for Economic Co-operation and Development/European Conference of Ministers of Transport. Specifically, the project examined the feasibility of introducing road surfacing materials with a service life in excess of 40 years [also known as long life surface course]. This target service life is at least twice as long as that typically expected from surfacings currently used in road pavements and would need to be demonstrated by the performance of any candidate materials. Herein the findings from an assessment of asphalt surfacing materials typically used in the UK, but modified with an epoxy binder, and their suitability for use in long life surface course, are presented. The work reported focuses upon evaluation of stiffness and tensile strength of manufactured specimens; in other related work, significant improvement in deformation resistance of epoxy asphalt has been reported. The research compliments other studies by participating laboratories in Denmark, New Zealand and the USA which have confirmed epoxy asphalt as a premium material that outperforms conventional binders on the important indicators of potential long service life.