ASSESSMENT OF THE DEFORMATION AND FLOW PROPERTIES OF POLYMER MODIFIED PAVING BITUMENS

Differences between the mechanical behaviour of bitumens and rubbers, both under low strain (linear response) conditions used in sinusoidal load testing and under extension to rupture, are indicated. The modification of the viscoelastic response of bitumens by the dispersion of small amounts of rubbers in them is then described, with particular reference to dispersions of sbs block co-polymers and digestions of comminuted scrap rubber. From considerations of the loading conditions imposed on the bitumen films present in a pavement surfacing, it was concluded that important modification by these additives was in the response to traffic loading at high pavement temperatures and thermal contraction loading at low pavement temperatures. Under these conditions of loading, the modified bitumens behave as low modulus elastic solids, showing limited permanent deformation by flow. This is in contrast to untreated bitumens where deformation by flow is the predominant response. A simple and rapid method for assessing the degree of modification produced by these additives has been developed. This involves creep testing in shear at 60 degrees C to a strain of 1.0 followed by measurement of the proportion of this strain which can be recovered when the load is removed. The relationship between the temperature, rate of loading and amount of strain conditions used in the testing and those imposed on the bitumen films in a pavement surfacing when subjected to traffic loading at high pavement temperatures is indicated. Probable limitations on the degree of modification which is practicable when 'rubberised' bitumens are used for spray sealing work are discussed (A). (TRRL)

• Record URL:
  • http://arrbknowledge.com
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00050164
• Corporate Authors:

  ARRB

  Melbourne, Victoria  Australia 
• Authors:
  • Dickinson, E J
• Publication Date: 1981-9

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 11-18
• Serial:
  • Australian Road Research
  • Volume: 11
  • Issue Number: 3
  • Publisher: ARRB
  • ISSN: 0005-0164

Subject/Index Terms

• TRT Terms: Bitumen; Creep; Creep tests; Deformation; Evaluation and assessment; Flow; Load tests; Loads; Pavements; Polymerization; Polymers; Rock fracture; Rubber; Rubberized bitumen; Strain (Mechanics); Temperature; Tests; Viscoelasticity
• Old TRIS Terms: Strains
• ITRD Terms: 4963: Bitumen; 4732: Creep (mater); 5595: Deformation; 9020: Evaluation (assessment); 5567: Load; 2955: Pavement; 7481: Polymerization; 7494: Rubber; 6722: Temperature; 6255: Test; 5935: Viscoelasticity
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00348832
• Record Type: Publication
• Source Agency: ARRB
• Files: ITRD, TRIS, ATRI
• Created Date: May 28 1982 12:00AM