THE EFFECT OF FLY ASH ON THE TEMPERATURE RISE IN CONCRETE. INTERIM REPORT

One of the most serious problems facing the concrete industry in Texas is the effect of high temperatures in concrete on concrete performance. Hot weather and the hydration of cement produce high temperature conditions. One of the major problems associated with high temperatures in concrete is the potential for thermal cracking. The temperature rise can be lowered through the use of mineral admixtures such as fly ash. This report is the first in a comprehensive study which addresses the effect of fly ash on the temperature rise in concrete and the thermal gradient in concrete resulting from the hydration of cement. This report presents the results from a research program in which the temperature rise in mortar samples and the thermal gradient in concrete are examined. Other tests were conducted to monitor the thermal gradient along the vertical cross section of concrete members having various dimensions, curing conditions, and mix proportions. The results of this study show that the replacement of cement with Type A fly ash results in a reduction in the temperature rise in concrete, whereas replacement of cement with Type B fly ash has no significant effect on the temperature rise in concrete. The results also show that the thermal gradient is not linear through the depth of a concrete member from mid-depth to the exposed concrete surface. Most of the temperature drop within a concrete member occurs near the exposed concrete surface. The project engineer is provided with guidelines to produce more durable concrete structures by reducing the internal concrete temperature, thus reducing the potential for thermal cracking.

• Record URL:
  • https://library.ctr.utexas.edu/digitized/texasarchive/phase2/481-2.pdf
• Supplemental Notes:
  • Research study title: Durability and Performance of Concrete Containing Fly Ash.
• Corporate Authors:

  University of Texas, Austin

  Center for Transportation Research, 3208 Red River Street
  Austin, TX  United States  78705

  Texas State Department of Highways & Public Transportation

  Transportation Planning Division, P.O. Box 5051
  Austin, TX  United States  78763

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Barrow, R S
  • Carrasquillo, R L
• Publication Date: 1988-2

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 198 p.

Subject/Index Terms

• TRT Terms: Admixtures; Cement; Concrete; Cracking; Durability; Fly ash; Guidelines; High temperature; Hydration; Mix design; Temperature; Temperature gradients
• Uncontrolled Terms: Concrete cracking
• Subject Areas: Highways; Materials; I32: Concrete;

Filing Info

• Accession Number: 00478192
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-88+481-2, Res Rept 481-2, CTR 3-5/9-87-481-2
• Contract Numbers: Study 3-5/9-87-481
• Files: TRIS, USDOT, STATEDOT
• Created Date: Dec 31 1988 12:00AM