USE OF ASTM TYPE-C FLY ASH AND LIMESTONE IN SAND-GRAVEL CONCRETE

Serious damage in concrete structures worldwide has been attributed to alkali-aggregate reactions. Field and laboratory work has demonstrated that silicious aggregates in wide regions in the midwestern United States can yield concrete with durability problems. This is the case for some sand-gravel aggregates in Kansas. To minimize durability problems, pozzolans, such as fly ash and limestone, have been suggested for use in concrete mixtures involving such aggregates. The use of two ASTM type-C fly ashes at 15% replacement of portland cement is evaluated. Also, the use of limestone (sweetener) from two sources as a 30% weight replacement of the sand-gravel is investigated. Thirty concrete mixtures were prepared with a water-to-cementitious materials ratio of 0.51. Eight approved and unapproved types of sand-gravel aggregates from different areas in Kansas were used. Concrete beams were cast and tested to determine the change in lengths and the modulus of rupture. Test results indicate that mixtures made with the two fly ashes have higher expansion and lower modulus of rupture when compared with mixtures containing no fly ash. Of the 16 concrete mixtures made with fly ash 15 failed to meet Kansas Department of Transportation specifications. The mixtures made with unapproved sand gravel and limestone had lower expansion and higher modulus of rupture when compared with concrete made with approved aggregates with no fly ash.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 44-49
  • Monograph Title: Concrete and concrete pavement construction
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00711779
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Sep 19 1995 12:00AM