TEXTURE CHANGES IN ROAD BASE MATERIALS IN SERVICE

This paper was presented to the 4th Australian Geological Convention, Hobart, January 1980. Research on mineralogical factors influencing the durability of crushed basalt when used as a road construction material has taken the form of a detailed comparison of rock from the source quarries with materials from road pavements, from specimens tested under repeat load triaxial test conditions and from material tested under rolling load conditions in a test track (road simulator) at Sydney University. The four quarries selected contain rock with a range of alteration mineralogy and part of the study relates to microscopical examination of petrological thin sections made from undisturbed samples of road base material, after impregnation with epoxy resin. These studies show that internal changes take place under the action of repeated loads, in that the -75 micrometre fraction becomes sorted and redistributed leading to the development of internal concentrations of smaller particles. A "texture factor" using point counting methods has been developed to quantitatively describe the observed sorting. Research to date indicates that these internal changes take place progressively with repeated loading and the "texture factor" has been used to compare the effect of repeat load testing, rolling under test track conditions and traffic during the service life of the road. The "texture factor" has promise as a possible indicator of the "in service" performance of different types of materials. (Author/TRRL)

  • Availability:
  • Corporate Authors:

    Geological Society of Australia, Incorporated

    Engineering Geology Spec Group, Challis House, 10 Martin Pl
    Sydney, New South Wales,   Australia 
  • Authors:
    • Wylde, L J
  • Publication Date: 1980-1

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 36-51

Subject/Index Terms

Filing Info

  • Accession Number: 00330410
  • Record Type: Publication
  • Source Agency: ARRB
  • ISBN: 0 86910 417 9
  • Report/Paper Numbers: Series No. 1
  • Files: ITRD, TRIS
  • Created Date: Sep 16 1981 12:00AM