Review of the design, characterisation and production of foamed bitumen stabilised base courses for pavement construction

ABSTRACT Foamed bitumen stabilisation is a unique pavement treatment option for improving new granular materials or rehabilitating existing granular layers that have exceeded their serviceable life. As a type of expedient construction technology, the application of foamed bitumen stabilisation technology to Australian pavements is exceptionally promising, with the product of the stabilisation process being a flexible material for use as base and subbase course, but with an increased modulus and reduced susceptibility to the effects of moisture ingress. Increasing demands on pavements, compounded with quality unbound pavement materials proving more difficult to acquire is necessitating the hauling of materials over long distances and this significantly increases typical pavement construction and maintenance costs. However, stabilisation of existing, marginal and non-standard granular materials can offer a logistically convenient and cost-effective solution. This paper reviews the design, construction and characterisation of foamed bitumen stabilised granular material for pavements. First, the technology of foamed bitumen stabilisation is summarised and then the design and production practices are reviewed, before concluding with future developments for stabilisation practices.