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The technology of production of die tooling based on high-alumina cement, used for the manufacture of aluminum alloys, transforming into a plastic state at high temperatures, is considered. This technology is based on the sol-gel method, characterized in that the formation of a crystalline high-strength structure for die tools based on high-alumina cement occurs cyclically with stage exposure at certain temperatures. First, a sol is formed-a free dispersed system, then a gel structure-a bound dispersed system. The final structure is crystalline, high strength with a compressive strength of up to 180-190 MPa. A distinctive feature is the possibility of destruction of the form after the manufacture of products. This is necessary because the manufactured products have a developed geometric shape and the product can not be obtained from the mold by ordinary removing the formwork.

Ключевые слова: бетон; неоднородность бетона; монолитные конструкции; прочность бетона; технологические факторы Неоднородность бетона является следствием неравномерного распределения его компонентов, физической и химической неоднородности продуктов гидратации цемента, результатом влияния изменчивости свойств компонентов, технологических параметров изготовления, доставки, укладки бетонной смеси и выдерживания бетона. При определении характеристик бетона на неоднородность влияют также ошибки методов испытаний, погрешности средств измерений, точность тарировки, причем это относится и к определению свойств компонентов бетона. В справочнике [1] неоднородность структуры бетона объясняется, главным образом, отличием свойств его составляющих. Подробный обзор проблемы неоднородности бетона содержится в [2]. Исследователями получены следующие результаты.

The main characteristics of concrete working under the influence of electricity are considered. In this regard, concretes can be divided into two main groups: electrically conductive and electrically insulating. Both of them have the right to exist, as the development of science and technology predetermines their necessity. Various attempts were made to determine the electrotechnical properties of concrete. The article presents a fundamentally new way to study the electrotechnical properties of concrete and mortars: the “voltmeter-ammeter” method. It is proved that the measurement of the specific resistance at frequencies of 1 … 5 kHz should be considered the most appropriate for carrying out the measurements. The experiments showed that this method has the right to exist, and is one of the simplest and does not require expensive equipment.

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