Laboratory and field evaluation of cold recycling mixture with foamed asphalt

Cold recycling with foamed asphalt stabilisation has been gaining acceptance and growing steadily. This study evaluates the performance of cold recycled mixes stabilised with foamed asphalt, with respect to the effects of confining stresses, and material moisture content. An experimental test section with a foamed stabilised recycled material used as the base course was monitored through quality control and quality assurance and falling weight deflectometer (FWD) tests. In laboratory, indirect tensile strength, triaxial resilient modulus, and permanent deformation tests were performed. Based on the results obtained, one can conclude that the curing is a critical consideration in terms of timing and its influence on pavement performance. Triaxial tests showed the stress dependency of this bitumen-stabilised material, while permanent deformation results indicated some potential for damage in early stages after construction. On the field evaluation, FWD data indicated the decrease in deflection with time, as a result of the increase in the layers stiffness.