IMPROVEMENT OF DEVICES FOR PRELIMINARY ELECTRIC HEATING OF CONCRETE MIXTURE

Purpose: The aim of this work is to create low-power and low-operational technology of electric heat treatment of concrete mixture and concrete. One of the most important tasks is the development of new approaches to the improvement of the concrete casting technology with the concrete mix heating during concrete placement. This requires elimination of the local overheating of the mixture and the rapid concreting of phase electrodes due to the development of the so-called edge effect. It occurs at the edges of electrodes, regardless of their shape. To realize the low-cost elimination of local overheating of the mixture and concreting of phase electrodes, it is necessary to study the behavior of the electric heat fields in the overheating zone. Outcomes: Based on this research, the improved device for the electric heat treatment of concrete mixture is proposed and patented. The device is based on the electrical field grading in the concrete mixture using narrow plates on phase electrodes. Research findings: The edge effect is based on the fundamental principle of the absence of the tangential component of charges on the electrode surface, that is, charges are in a mutually balanced state. This condition is provided by their accumulation on the edges of electrodes. The resulting non-uniformity of the electric field strength and current density lead to negative consequences. But this non-uniformity is manifested in the local area at the end of electrode and can be stopped at the electrode end by a narrow dielectric strip.