FACTORS INFLUENCING FLOW AND STRENGTH OF STANDARD MORTARS AND REAPPRAISAL OF ASTM TEST METHODS FOR FLY ASH

Modified Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use as a Mineral Admixture in Portland-Cement Concrete (American Society for Testing and Materials [ASTM] C 311) Pozzolanic (Strength) Activity Index tests with five fly ashes and two portland cements were conducted to compare results with those of standard tests. By varying the sand contents, strengths of 38 deg C cured mortars decreased -30 to -50 kPa/g of sand added in mixes containing 1370 to 1570 g of sand for different cement/fly ash blends. By varying the water contents, strengths varied -125 to +190 kPa/mL, strengths tending to increase because of paste volume increases with water content. Flow of mortars in both tests increased almost linearly with paste volume fractions. Accelerated curing at 38 deg C for tests at 28 days usually yielded higher relative strengths than after curing at 23 deg C for 91 days. Multiple linear regression equations employing both kinds of test data are solved at specified flow and strength values to determine proportions and mortar volume yields. This more general performance test ranks fly ashes by mortar volume yield at equal flow and strength, and is suggested as a substitute for Strength Activity Index test.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/3528769
• Corporate Authors:

  American Society for Testing and Materials (ASTM)

  100 Barr Harbor Drive, P.O. Box C700
  West Conshohocken, PA  United States  19428-2957
• Authors:
  • Helmuth, R
• Publication Date: 1996-12

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 98-111
• Serial:
  • Cement, Concrete and Aggregates
  • Volume: 18
  • Issue Number: 2
  • Publisher: American Society for Testing and Materials (ASTM)
  • ISSN: 0149-6123
  • Serial URL: http://journalsip.astm.org/JOURNALS/CEMENT/cca_home.html

Subject/Index Terms

• TRT Terms: Flow; Fly ash; Mortar; Portland cement; Pozzolanic action; Proportion; Specifications; Standards; Strength of materials; Test procedures
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00730843
• Record Type: Publication
• Files: TRIS
• Created Date: Feb 3 1997 12:00AM