Successful demonstration of lower temperature asphalt on the UK strategic road network

Abstract

Lower temperature asphalts (LTAs) have been identified as a way of reducing both the energy required to produce and lay asphalt materials and the nuisance of fumes for workers. The use of LTAs has not yet reached its full potential in the United Kingdom. To encourage uptake in appropriate applications and inform the national specifications, a project was undertaken to demonstrate use of a LTA on the strategic road network. The project was realised as a result of successful collaboration between the national road authority, industry and a research organisation. A site with sections of LTA surface and binder course mixtures produced using an 'injection foaming' technology was laid and monitored for initial properties. Sections of conventional hot mix materials were also laid and monitored to enable direct comparison. Visual inspection, temperature measurement and thermographic imaging were undertaken at regular intervals throughout construction. Physical properties of the materials used were established through laboratory testing of samples taken at site and the carbon footprint of construction was evaluated. Overall, the demonstration proved that effective application of an LTA technology could be achieved but also yielded some important practical messages for the future application of LTAs.