FOAMED BITUMEN ROAD RECYCLING

Brief details of road recycling projects in the UK which have used Foamstab foamed bitumen are provided in this article. Foamstab has a wide range of applications from in situ rehabilitation of failing roads through providing new low cost asphalt bases and sub bases to stabilising waterproof working platforms for all classes of road. The advantages of Foamstab are described, together with advice on the type of site investigation and traffic evaluation required to provide information essential for accurate design. Details about pavement design and construction methods used are also given, and advice on the suitability of existing materials for the foamed bitumen technique is provided using an aggregate grading chart. A table giving surfacing and Foamstab base thicknesses for various traffic flows is also provided. Experience so far indicates that reconstruction costs using Foamstab can be as low as half that of traditional methods, traffic delays only a third and energy consumption little more than a tenth. Some typical energy usage figures are quoted from the energy efficiency office demonstration project in Dartford, Kent. (TRRL)