Supplying temperature-controlled concrete for any major construction site is a must all over the world. The development of the strength in concrete is accompanied by evolution of heat as the cement cures and hardens (heat of hydration). In small structures this phenomenon is not of importance, but very significant in mass concrete, for instance for dam projects. The heat of hydration raises the temperature during the curing process by up to 25° causing an increase of volume. After the curing the concrete cools down, again reducing its volume and thus naturally causing cracks eventually. Therefore the initial pouring temperature should be lowered so much that the maximum temperature during the curing process does not exceed a certain temperature determined by the consultants.
Although the required pouring temperatures of the concrete vary from site to site and from country to country (from +7 °C to max. 30 °C) there is always a requirement for a sophisticated refrigeration system. As the initial and the running costs for such a refrigeration system are quite high (they even can be higher than the ones of the concrete batching plant itself), it is essential for the contractor to have an optimised system installed.
Concrete Mixing Temperature
as function of water temperature and addition of ice respectively