INFLUENCE OF MOISTURE ON THE STRENGTH AND WEARING PROPERTIES OF ROAD AGGREGATE

FUKTIGHETENS INVERKAN PA STENMATERIALS HALLFASTHETS- ON NOETNINGSEGENSKAPER

Investigations are reported of the impact and crushing strengths of aggregates comprising both airdry specimens and specimens which have been stored in water for 24 hours. In most cases tests carried out after more extreme drying or water absorption gave rise to little additional effect. It was found that certain aggregates may have a higher strength in the wet condition (white synthetic aggregate, quartzite, marble) in testing the impact strength. In crushing tests, these aggregates are little affected by moisture, even if no increases in moisture are observed. Some aggregates deteriorated more or less markedly in the presence of moisture, the species which were affected most being those with a large proportion of mica, or secondary hygroscopic minerals. The order of magnitude of the moisture effect also depends on the manner in which the degree of crushing after testing is evaluated. It is probable that moisture also promotes the decomposition of an unbound aggregate into fine grains in road conditions. The results of point load tests carried out on individual particles are discussed, as well as the results of abrasion tests performed with a grinding wheel and an emery powder. Previously performed wet degradation tests are discussed in which the aggregate was treated in test cylinders in a rotary attrition apparatus. The greatest wet attrition was obtained in the case of argillaceous sedimentary rocks. The observation is made that it is logical to perform aggregate tests on wet samples as a matter of routine at all times. The findings are also presented of a study of the literature pertaining to this subject.

  • Corporate Authors:

    Swedish National Road and Traffic Research Institute

    Drottning Kristinas Vaeg 25
    S-11428 Stockholm,   Sweden 
  • Authors:
    • HOEBEDA, P
  • Publication Date: 1974

Language

  • Swedish

Media Info

  • Features: Figures; Photos; References; Tables;

Subject/Index Terms

Filing Info

  • Accession Number: 00080823
  • Record Type: Publication
  • Report/Paper Numbers: No. 42
  • Files: TRIS
  • Created Date: Mar 6 1975 12:00AM