IMPROVEMENT OF THE DEFORMATION BEHAVIOUR OF BITUMEN BOUND BEARING COURSES BY ADDITION OF ANGULAR AGGREGATES

DIE VERBESSERUNG DES VERFORMUNGSVERHALTENS BITUMENGEBUNDENER TRAGSCHICHTEN DURCH ZUSATZ VON KANTKORN

The improvement in the deformation resistance of bituminous bearing course mixes was investigated experimentally. It was apparent that the differentiation between angular or rounded aggregate alone does not suffice to predict certain mix properties, because factors such as surface roughness, the degree of angularity or roundness, and particle shape have a significant influence. Surface characteristics have only a small influence at low temperatures because of the cohesion of the bitumen, but become significant from 60 degrees celsius. Other parameters being equal, the differences in surface roughness of rounded aggregates have a significant effect on the deformation resistance at higher temperatures, but in the case of very smooth rounded aggregates even small additions of angular material lead to marked improvements in the stiffness of the mix. The minimum proportion of angular material depends on the surface roughness of the rounded aggregate and therefore is subject to regional variations. For this reason it is suggested that test mixes of varying formulations be prepared from the locally available angular and rounded aggregates to provide samples for determination of the dynamic deformation modulus. The number of tests required can be reduced by utilisation of optical assessment of the surface properties of the aggregate - a method for this is proposed - thus enabling the design of bituminous pavement mixes to be optimised on a material cost basis. (TRRL)

• Corporate Authors:

  Ministry of Building and Technology, Austria

  Stuberring 1
  A-1010 Vienna,   Austria 
• Authors:
  • Eppensteiner, W
  • Fuereder, H
  • Krzemien, R
• Publication Date: 1979

Language

• German

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 11-57
• Serial:
  • Strassenforschung
  • Issue Number: 120
  • Publisher: Ministry of Building and Technology, Austria

Subject/Index Terms

• TRT Terms: Aggregates; Aggregates by shape and surface texture; Angularity; Bearing capacity; Bitumen; Bituminous mixtures; Costs; Deformation; Dynamic modulus of elasticity; Evaluation and assessment; Improvements; Materials tests; Mix design; Optical measurement; Optimization; Particles; Research reports; Roughness; Rounded aggregates; Samples; Temperature; Tests; Texture
• Uncontrolled Terms: Aggregate shape; Aggregate testing; Roundness
• ITRD Terms: 4577: Aggregate; 5945: Angularity; 3085: Bearing capacity; 4963: Bitumen; 4967: Bituminous mixture; 5595: Deformation; 9020: Evaluation (assessment); 4511: Particle; 8559: Research report; 4569: Rounded aggregate; 6251: Sample (mater); 3053: Surface texture; 6255: Test
• Subject Areas: Finance; Geotechnology; Highways; Materials; I31: Bituminous Binders and Materials; I36: Aggregates;

Filing Info

• Accession Number: 00341674
• Record Type: Publication
• Source Agency: Bundesanstalt für Straßenwesen (BASt)
• Report/Paper Numbers: Monograph
• Files: ITRD, TRIS
• Created Date: Dec 22 1981 12:00AM