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An investigation into the influence of size on the mechanical properties of aggregates

  • N. Turk
  • W. R. Dearman
Article

Abstract

Tests have been carried out according to British Standard BS 812-1975 on non-standard and standard size aggregates to study the influence of aggregate size on mechanical properties. Dolerite, granite, limestone aggregates of different sizes have been tested. No basic relations have been found between elongation index, IE, and flakiness index, IF, and the different aggregate sizes. Aggregate impact value, AIV, aggregate crushing value, ACV, and 10 per cent fines loads, however, are aggregate size dependent. Tests on larger aggregate sizes give higher test values, whereas tests on smaller aggregate sizes give lower values than test results for standard size aggregates. For each rock type there is a different set of sieve sizes, from those recommended in BS 812-1975, which give the same values as the standard sieve sizes. Additionally, relations have been determined for the mechanical test results for the different size aggregates.

Keywords

Rock Type Aggregate Size Crushed Rock Sieve Size Aggregate Impact 

Étude de l'influence de la taille des granulats sur leurs propriétés mécaniques

Résumé

Des essais ont été réalisés selon la norme britannique BS 812-1975 sur des granulats à granularité normalisée ou non pour étudier l'influence de la taille des granulats sur leurs propriétés mécaniques. Des granulats doléritiques, granitiques et calcaires de granularités variées ont été soumis aux essais. Aucune corrélation n'a été trouvée entre l'indice d'allongement IE et d'aplatissement IF et les différentes classes granulaires. Par contre, les coefficients de résistance aux chocs AIV, de résistance au broyage ACV et l'essai des 10% de fines dépendent de la taille des granulats. Les valeurs obtenues sur des granulats plus grossiers sont plus élevées alors que celles obtenues sur des granulats plus fins sont plus basses que celles obtenues sur les granulats normalisés. Pour chaque type de roches on utilise un jeu de tamis différent de ceux recommandés dans la norme BS 812-1975 mais qui donnent les mêmes valeurs que la gamme de tamis normalisée.

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References

  1. BS 410-1976, Specification for Test sieves. British Standards Institution. 15 p.Google Scholar
  2. BS 812-1975: Methods for sampling and testing of mineral aggregates (in four parts). British Standards Institution.Google Scholar
  3. DEPARTMENT OF TRANSPORT, 1976: Specification for road and bridge works. Technical Merrorandum H16/76, specification requirements for aggregate properties and texture depth for bituminous surfacings to new roads.Google Scholar
  4. DHIR R.K., RAMSAY D.M. and BALFOUR N., 1971: A study of the aggregate impact and crushing value test. J. Inst. Highway Eng. 18, 17–27.Google Scholar
  5. EDWARDS A.G., 1967: Properties of concrete made with Scottish crushed rock aggregates. U.K. Building Research Station, Garston, Engineering Paper No: 42.Google Scholar
  6. G.S.A. COLOR-CHART, 1970. Rock color chart. The Geological Society of America, Boulder, Colorado, U.S.A., pp. 16.Google Scholar
  7. HARTLEY A., 1970: The influence of geological factors upon the mechanical properties road surfacing aggregates (with particular reference to British conditions and practice). Proc. 21st Highway Geol. Univ. of Kansas.Google Scholar
  8. HARTLEY A., 1974: A review of the geological factors influencing the mechanical properties of road surface aggregates. Quarterly Journal of Engineering Geology, 7, 69–1000.CrossRefGoogle Scholar
  9. MARKWICK, A.H.D. and SHERGOLD F.A., 1945: The aggregate crushing test for evaluating the mechanical strength of coarse aggregate. Journal of Institution Civil Engineers, 24 (b), 125–133.CrossRefGoogle Scholar
  10. RAMSAY, D.M., 1965: Factors influencing aggregate impact value in rock aggregate. Quarry Mgrs J1, 49, 129–34.Google Scholar
  11. RAMSAY D.M., DHIR R.K., and SPENCE J.M., 1973: Non-geological factors influencing the reproducibility of results in the aggregate impact tests. Quarry Mgrs J1, 57, 179–181.Google Scholar
  12. RAMSAY D.M., DHIR R.K., and SPENCE J.M., 1974: The role of rock and class fabric in the physical performance of crushed rock aggregate. Engineering Geology, 8, 267–285.CrossRefGoogle Scholar
  13. ROAD RESEARCH LABORATORY, 1959: Roadstone test data presented in tabular form, Road Note 24, H.M.S.O., London.Google Scholar
  14. SABINE P.A., MOREY J.E. and SHERGOLD F.A., 1954: The correlation of the mechanical properties and petrography of a series of quartz dolerite roadstones. J. Appl. Chem., 4, 131–137.CrossRefGoogle Scholar
  15. SHERGOLD F.A., 1950: The classification and mechanical testing of road making aggregates. Quarry Mgrs J1, 34, 27–35.Google Scholar
  16. SHERGOLD F.A., 1963: A study of the variability of roadstones in relation to sampling procedures. Quarry Mgrs. J1 47, 3–8.Google Scholar
  17. SPENCE J.M., RAMSAY D.M. and DHIR R.K., 1974: A conspectus of aggregate strength and the relevance of this factor as the basis for a physical classification of crushed rock aggregate. Proc. 3rd Int. Rock Mech. Conf., Vol. 2A, 79–84, Denver, U.S.A.Google Scholar

Copyright information

© International Assocaition of Engineering Geology 1988

Authors and Affiliations

  • N. Turk
    • 1
  • W. R. Dearman
    • 2
  1. 1.IzmirTurkey
  2. 2.Department of Geotechnical EngineeringThe University of Newcastle Upon Tyne NEIEngland

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