The adoption of field blended crumb rubber binders in South Australia: an exercise in innovation and co-operation between the public and private sectors

A number of high profile spray seal stripping failures involving SBS based polymer modified binders (PMBs) instigated a study looking at binder properties at the point of delivery. On the basis of these investigations consideration was given to alternatives to factory produced PMBs. Crumb rubber modified (CRM) binder was seen as an existing technology that had provided excellent service in the eastern states. This encouraged the Department of Transport Energy and Infrastructure (DTEI) to undertake several trials and subsequently let state wide contracts. The Department’s commitment to the evaluation of field blended crumb rubber binder was seen by Pioneer Road Services (PRS) as an opportunity to closely investigate the properties of this product and to improve its blending techniques. The ongoing interest by DTEI in field blended CRM binders has provided Pioneer Road Services with the confidence to make a major investment in the development of an innovative, state-of-the-art field blending plant. This paper discusses the introduction of CRM rubber binder for spray sealing in South Australia and outlines the process leading to the development of the new plant and equipment required for its efficient production.