Foamed bitumen stabilisation in New Zealand: projects, do's and don'ts, performance

Fulton Hogan introduced the first purpose built stabilisation hoe to New Zealand for stabilising pavements with foamed bitumen in 2004. Many lessons have been learnt during the introduction of this “new” technology into New Zealand, including the pavement and laboratory investigation, procurement, operational and surfacing aspects of the work. The first two foamed bitumen treated pavement projects carried out by Fulton Hogan involved rehabilitation of pavements on moderately and heavily trafficked State Highways. Four years later these are still performing as expected in terms of the design and performance. In this paper a closer analysis is carried out on these two projects in terms of the performance based on falling weight deflection measurements and high speed data. In addition typical applications to date, aspects of procurement, and lessons learnt in terms of pavement investigation, laboratory performance testing, incorporation of the subgrade into the treated basecourse and sealing are discussed. (a)