ENHANCING BITUMEN PRODUCTS WITH SCRAP RUBBER

Several state road authorities are using scrap rubber modified binders to prevent or delay the onset of reflection cracking or to improve aggregate adhesion in areas where traffic stressing is high. The scrap rubber crumb is normally digested at high temperature in bitumen in a sprayer immediately before application. The work carried out at the Australian Road Research Board was to identify those factors which are of importance in optimising binder performance. A simple and rapid test procedure was developed to measure the response under loading conditions approaching those which are important in pavement service. The procedure is to subject a prism of the binder at 60 degrees C to a shear strain of 1.0 in creep and then determine the elastic recovery when the stress is removed. Most of the scrap rubber produced from vehicle tires is synthetic (styrene-butadiene rubbers). These rubbers are thermally stable when digested in bitumen at temperatures of the order of 200 degrees C and the elasticity of the product is primarily dependent on rubber concentration and the morphology structure of the particles. Particle morphology, in turn, is determined by the method used for comminuting the bulk material. By using special methods to produce the particles, the elastic recovery of a digestion can be markedly increased over that obtained when particles from the conventional tire retreading process are used. The tread of highway truck tires is usually a vulcanised natural rubber. Digestions of scrap particles from this source have a better elastic response than equivalent synthetic rubber digestions but are not so stable to heat treatment. The time of digestion at which maximum elastic recovery occurs depends on particle size and morphology, for natural rubber scrap (a). (TRRL)

• Record URL:
  • http://arrbknowledge.com
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0869100599
• Supplemental Notes:
  • 19th ARRB Regional Symposium, Wagga Wagga, New South Wales, 1982. Program and Papers. This paper was presented in Session 3--Stretching the Sealing Dollar.
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Authors:
  • Oliver, JWH
• Publication Date: 1982

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 117-131
• Serial:
  • Publication of: Australian Road Research Board
  • Publisher: ARRB
  • ISSN: 0005-0164

Subject/Index Terms

• TRT Terms: Adhesion; Aggregates; Binders; Bitumen; Conferences; Cracking; Durability; Elasticity (Mechanics); Load tests; Loads; Particles; Prevention; Reflection cracking; Rubber; Rubberized bitumen; Temperature; Test procedures; Tires
• ITRD Terms: 5942: Adhesion; 4577: Aggregate; 4948: Binder; 4963: Bitumen; 8525: Conference; 5211: Cracking; 5910: Durability; 5912: Elasticity; 5567: Load; 4511: Particle; 7494: Rubber; 6722: Temperature; 6288: Test method; 1381: Tyre
• Subject Areas: Geotechnology; Highways; Materials; Security and Emergencies; Vehicles and Equipment; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00368001
• Record Type: Publication
• Source Agency: ARRB
• ISBN: 0 86910 059 9
• Files: ITRD, TRIS, ATRI
• Created Date: Dec 30 1982 12:00AM