Title: Heat of Hydration of High-Strength Concretes

Author(s): S. Smeplass and M. Maage

Publication: Symposium Paper

Volume: 121

Issue:

Appears on pages(s): 433-456

Keywords: adiabatic conditions; calorimeters; cement content; silica fume; heat of hydration; high-strength concretes; temperature rise (in concrete); tests; water-cementitious ratio; Materials Research

DOI: 10.14359/2557

Date: 11/1/1990

Abstract:
Heat of hydration of a selection of high-strength concretes has been investigated by means of a so-called semiadiabatic calorimeter test. The temperature development within a hardening specimen enclosed in an insulated container is used as basis for a simulation of the adiabatic temperature increase and the specific heat development of the cement. The results indicate that the heat of hydration can be affected within a relatively wide range by the utilization of traditional mix design parameters. Heat of hydration is affected not only by the cement content but also by the water/cementitious ratio {w/(c + s)} and the silica fume content. The heat of hydration per cement unit decreases approximately 9 percent when the w(c + s) is reduced form 0.36 to 0.27. At w(c + s) 0.50, the replacement of cement by silica fume on a 1:1 basis induces a significant increase in the heat evolved per cement unit. The increase corresponds approximately to the reduction in cement content. Hence, the temperature rise in the concrete is not significantly affected. The ability of the silica fume to increase the heat evolvement of the cement decreases with decreasing w(c + s), and is negligible at w(c + s) 0.27. Hence, a replacement of cement by silica fume on a 1:1 basis at this w(c + s) leads to a lower temperature rise of the concrete.