THE PERFORMANCE OF SLAG ROADBASES UNDER ACCELERATED TRAFFICKING - RESULTS AND FINDINGS OF THE PROSPECT ALF TRIAL

Slag has been used in pavements for years in areas from Wollongong to Newcastle (NSW), but in recent years the nature of the slag has changed. With changes in the ironmaking process, the chemical composition of the blast furnace slag has altered and the crushing strength has dropped. Although similar material has a history of pavement usage abroad, no evidence could be found of its use under heavy traffic with only a thin bituminous seal. During the Prospect ALF trial over 2 million loading cycles were applied to 18 test sections in order to examine the relative performance of unbound and stabilized slag materials. The experiments indicated that slag can be used in place of high quality crushed rock in road bases. The slag and the stabilized slag materials proved to be suitable for the intended purpose (i.e. to replace crushed rock and stabilized crushed rock materials) provided the slag and slag mixes are protected from excessive tensile strains by an adequately strong subgrade and from surface wear by an adequate wearing course, preferably asphalt. The pavement failures observed during the experiments could be explained by the influence of local conditions not related to the performance of the base layers. The most common causes of local failure were the cracking of the bituminou s seal, local soft spots in the subgrade, the separation of a levelling layer and the combination of heavy rainfalls, weak subgrade support and damaged seal. The performance of the stabilized slag materials and crushed rock was difficult to compare, as the curing of the stabilized slag materials occurred during a longer period of time.

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  • Corporate Authors:

    ARRB

    Melbourne, Victoria  Australia 
  • Authors:
    • KADAR, P
    • Walter, P
  • Publication Date: 1989

Media Info

  • Pagination: v.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00495230
  • Record Type: Publication
  • ISBN: 0 86910 417 9
  • Report/Paper Numbers: ARR No. 170
  • Files: TRIS
  • Created Date: Jul 31 1990 12:00AM