 Improving workability Extensive testing and field trials have demonstrated that these binders are more viscous at temperatures below 100°C than reference unmodified bitumens. At temperatures above 115°C the binders exhibit lower viscosity and thus better flow and coating behaviour, which improves the workability of the asphalt mixture. Extending the laying window The aforementioned improvement in workability of asphaltic materials manufactured with the modified binder system also gives additional benefits of extending the ‘lifetime’ of the mixture. Shell S-Grades mixtures can be successfully compacted at lower temperatures, therefore providing the material is manufactured at conventional temperatures transport time can in most cases be extended significantly. Improvement in logistics Frankfurt Airport is the second biggest Airport in Europe. The re-surfacing of the North Runway in 2004/5 was undertaken using asphalt manufactured with Shell ‘S’ grade binders. Over 400,000 tonnes of asphalt was laid on this previously concrete runway during short night shifts. This was achieved by completing a single 15m wide section each night for 300 nights. Each section required a full depth reconstruction involving 1,500 – 2,000 tonnes of asphalt comprising 600mm of asphalt laid in three layers. Savings in energy costs Use of these modified binders allows plants to manufacture asphalt at much reduced temperatures. Reducing temperatures by 20 - 30°C, can produce savings in the order of 7.5%, which equates to approximately 0.5kg fuel per tonne of asphalt produced. Download the S Grade Binders Brochure [PDF 413KB] - link opens in a new window | 
