Marginality in Crushed Aggregate Gradations and Mechanical Properties of Pavement Concrete

Scarcity and depletion of good quality virgin aggregates is pushing engineers towards the use of marginal aggregates. Marginal mix designs are the future of infrastructure construction. This paper reports a laboratory study of fly ash concrete mixes incorporating marginal crushed fine aggregates. Mixes with cement replacements of 30, 40 and 50% with fly ash are used. Mechanical properties in terms of compressive and tensile strength are reported. Measurements of elastic modulus and time rate of abrasion resistance are also described. It was observed that marginal aggregates could successfully be utilized in pavement concretes provided proper evaluation of aggregate gradings and optimization of mixes could be achieved. Different size fractions of aggregates play specific and/or explicit roles in the development of specific strength type (compressive, bending or splitting tension). Moreover gradually evolving pozzolanic reactions contribute in improving the long term strength and the ratio of tensile to compressive strength. To a certain extent, the nature of stress-strain curves depends on the aggregate grading and fly ash content. Similarly the abrasion resistance and the time-rate of wear due abrasion load depends to a greater extent on the fine aggregate grading, paste constitution, curing and to a relatively lesser extent on the compressive strength.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 17p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01045147
  • Record Type: Publication
  • Report/Paper Numbers: 07-2606
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 7:18PM