Wärmebehandlung von Frischbeton unter Nutzung der Radiowellen-Technologie

Radio wave technology used for heat treatment of fresh concrete

The economical production of industrially-produced concrete elements aims for low cycle times in order to be able to reuse the forms and form-works as soon as possible. Therefore it is necessary that the concrete develops a high early strength to reach the needed demoulding strength. To accelerate the hydration process it is possible to heat the fresh concrete. The subject of this article is to present a new procedure for heat treatment of fresh concrete which enables an energy-efficient, temperature-controlled heating. Due to the electromagnetic field of the radio wave technology the fresh concrete can be heated by means of dielectric heating in order to enable homogenous temperature increases. Due to the combination of temperature measurement and energy input it is possible to keep certain temperature characteristics and maximum temperatures that had been defined before; an exact temperature control is guaranteed. The aim of the research about the effects of dielectric heating on early and final strength, as well as the structural development in the concrete, are described. In order to get the broadest possible image the structure of the heat-treated concrete is examined with different methods.