Determination of the thermal conductivity of concrete during the early stages of hydration

A knowledge of the thermal conductivity of concrete during the early hydration period (7 days) is essential to obtain an accurate estimate of the thermal stresses that will develop in a concrete structure as a result of the heat produced by the binder during hydration. This paper describes a probe that is capable of measuring the thermal conductivity of a 2 kg concrete or mortar sample during all stages of hydration. A method of calculating the thermal conductivity of concrete with large aggregates from the measured conductivity of the mortar and the conductivity of the aggregates is also discussed.