A new methodology for determining thermal properties and modelling temperature development in hydrating concrete

Abstract

A method is described for determining both the rate of heat generation and the time-dependent thermal properties of concrete so that the temperature development in a concrete section can be modelled. The method uses measured temperature data from concrete prisms and involves fitting data from the sample prisms of concrete to a simple theoretical heat-flow model. It is intended to facilitate on-site tests of concrete mixes; the resulting data can be used in computer models to predict the stresses that can lead to early thermal cracking in large pours.The method is tested by using the thermal properties obtained from the model to predict the temperature versus time profile at a number of locations in a large rectangular block of concrete and comparing these predictions with measured temperatures from the block.3

Numerical identification of the thermal properties of early age concrete using inverse heat transfer problem

“…Also a widely used hot wire method is based on a solution of an inverse problem [19]. To the best of authors' knowledge only two papers [20,21] deal with problem similar to the one presented in this paper. The authors of [20] determined time-dependent thermal properties of concrete only for synthetic data.…”

“…Based on the simulation results this method was found adequate. The authors of [21] presented a similar method, called a prism method, because of the shape of the measurement moulds, used in the experiment. The temperature was recorded along the axis of the four concrete prisms.…”

Estudio experimental sobre la influencia de la temperatura ambiental en la resistencia del hormigón preparado. Bases teóricas

“…Most good practice manuals, which tend to be very academically oriented, merely recommend reducing the temperature of concrete components or avoiding concrete fabrication and casting when the outdoor temperature is high. The solutions proposed include: minimizing the cement content by using chemical and mineral admixtures, using low heat of hydration cements, storing materials in the shade and moistening them with cold water, and cooling the fresh concrete with liquid nitrogen (10)(11)(12)(13)(14)(15)(16).…”