Research – making innovation mainstream AustStab 20 th Annual Conference Excellence in Research or Education

Providing tools to consider in situ stabilised subgrades and bases in structural designs Partnering with agencies and industry

Austroads guides did not consider lime stabilised subgrades to provide structural contribution to designs … only two state road agencies did … and they used different methods! Research provided basis for: – agreement that lime stabilised subgrades be considered equivalent to selected fill materials – inclusion within Austroads mechanistic method – inclusion within Austroads empirical design method for lightly and heavily trafficked pavements Lime stabilised subgrades

Documented in – report for Austroads Implemented in – AustStab Technical Note 8 – Austroads Guide to Pavement Technology: Part 2: Pavement Structural Design (release 2016) Lime stabilised subgrades Source: Hiway Stabilizers

Research to increase use of foamed bitumen stabilisation Completed three years of five year project Collaborating with industry and state agencies Improving Austroads procedures for design of FBS pavements Design of FBS pavements

Interim procedures – mix design – test methods – structural design Field trials – under-designed pavements – ongoing monitoring – parallel laboratory testing – identifying distress modes Design of FBS pavements

Research aimed at increasing the use of lightly bound materials Widespread use hampered by fears of cracking New research focussing on ensuring that cracking is the “right” kind of cracking and serviceability is maintained Increasing lightly bound material use