Apparent Activation Energy and Equivalent Age of Concrete Influenced by Curing Temperature History
By Norio Ito, Hirozo Mihashi and Kazuki Kirikoshi

Concrete Research and Technology
Vol.15, No.1, Jan 2004 (Issue 34)


Synopsis:
While concrete properties are influenced by curing temperature history, their variation can be described by a unique function by introducing a concept of equivalent age if the activation energy is rationally determined. Cement paste, mortar and concrete are made with two types of cement, ordinary Portland cement and low-heat Portland cement. In this study, they are cured at a constant temperature of 20°C, 40°C or 60°C until the test age. Experiments on compressive strength, static modulus of elasticity, dynamic modulus of elasticity and fracture energy are executed. On the basis of these experimental results of hardened cement paste, mortar and concrete cured at different temperatures, the values of apparent activation energies are evaluated and the development of these properties is discussed as a function of equivalent age.
Keywords:
cement types, curing temperature, concrete, mechanical properties, apparent activation energy, equivalent age

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