Publisher's Synopsis
Experience in France has shown that roadbase materials with high stiffness can have considerable advantages over conventional roadbases. This report describes full-scale road trials of high modulus base (HMB), a high stiffness roadbase macadam manufactured to the standard UK composition for dense bitumen macadam. In trials across a range of conditions, HMB was found to behave in a way similar to conventional roadbase macadams, and it was determined that HMB could be mixed, laid and compacted without difficulty by standard UK plant. The superior load-spreading properties of HMB mean that it can be thinner, and thus more economical, providing savings of up to 25 percent and still having the same lifespan. Alternatively, if used at current roadbase thickness, HMB will provide a longer pavement life. Because of its high resistance to deformation, HMB would also offer excellent rutting resistance when used in conjunction with a thin surfacing or a rut-resistant wearing course.
