Determination of apparent activation energy of concrete by isothermal calorimetry

• Published in: Cement and concrete research Vol. 30; no. 2; pp. 301 - 305
• Main Authors: Kada-Benameur, H., Wirquin, E., Duthoit, B.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 01.02.2000; Elsevier Science
• Subjects: Apparent energy activation; Applied sciences; Buildings. Public works; Concrete; Concretes. Mortars. Grouts; Degree of hydration; Exact sciences and technology; Fluxmeter; Isothermal calorimeter; Materials; Properties and performance of fresh concrete; Temperature; Degree of hydration; Temperature; Concrete; Isothermal calorimeter; Fluxmeter; Apparent energy activation; Hydration; Calorimetry; Experimental device; Experimental study; Activation energy; Heat liberation
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/S0008-8846(99)00250-1

In recent works at our laboratory, instrumentations have been developed to carry out calorimetric tests on concrete in isothermal conditions, which give much information. The objective of this article is, on the basis of this technique, to study the validity of the Arrhenius law and to determine the evolution of apparent activation energy of the concrete. This parameter is necessary for the calculation of the maturity of the concrete. Measurements of hydration heat have been carried out for various conditions of isothermal curing and have allowed us to study the evolution of apparent activation energy according to the degree of hydration. Generally, activation energy is constant for a degree of hydration ranging between 5 and 50%. On the other hand, we have observed that this parameter varied with the temperature, which limits the use of this technique to thin elements.