Title: Creep of Mass Concrete Containing Fly Ash at High Temperatures

Author(s): Karim W. Nasser and H. M. Marzouk

Publication: Symposium Paper

Volume: 76

Issue:

Appears on pages(s): 451-462

Keywords: age-strength relation; compressive strength; creep properties; creep recovery; creep tests; curing; fly ash; -- temperature; mass concrete; pressure vessels; stresses.

DOI: 10.14359/6799

Date: 10/1/1982

Abstract:
The present tests were made to measure creep of mass concrete containing fly ash at six different temperatures of 70 to 450 F (21.4 to 232 C). At each temperature three stress levels were applied for over 20 months and they were 750, 1200, and 1500 psi (5.17, 8.27, and 10.34 MPa). The results showed that, in general, creep strains increased with a rise in temperature, and the maximum increase occurred at 450 F (232 C). It was also found that beyond 180 days, creep strains vary linearly with stress-strength ratios at temperatures of 70, 160, 350, and 450 F (21.4, 71, 177, and 232 C). However, at temperatures of 250 and 300 F (121 and 149 C), the strains were non-linear with stress-strength ratios at all ages. Based on the experimental results, a basic expression for creep of mass concrete containing fly ash at high temperature was suggested. Results of previous investigation on the effect of high temperature on the strength and elasticity of concrete con-taining fly ash were used to explain the creep behavior at various temperatures.