The law of affinity of structures developed by the authors is based on basic properties and regularities inherent in the basic and bonding material and the combination of properties that ensure properties of the contact layer for reliable and durable construction operation. In recent decades, new composites with a number of required physical, mechanical and operational properties have been developed. To produce modern efficient materials which would be uniform, strong and durable, it was proposed to apply the law of affinity of structures.
Introduction. Mixing of dry components in mixers is one of the most important stages of any technological process in the manufacture of a composite material. To date, various technologies use a wide variety of mixing equipment, which is characterized by different principles of mixing and design solutions. Of particular interest for the preparation of high-quality and homogeneous mixtures for heat-insulating purposes is a pneumatic mixer with a spiral energycarrying tube. The article presents the results of studies using the method of mathematical planning of the fullfactor ПФЭЦКРП24 experiment, which makes it possible to most adequately assess the ongoing processes while minimizing systematic errors.Materials and methods. In the work, ЦЕМ 0 42,5Н ГОСТ 31108–2020 Portland cement with a specific surface area of 308 m2 / kg, sand of the Volsky deposit were used as raw materials for testing. Expanded vermiculite obtained as a result of heat treatment of natural vermiculite at a temperature of about 700°C was used as a light filler.Results. Heat-insulating mixtures prepared in a pneumatic mixer with a spiral energy-carrying tube ensure the production of heat-insulating mortars with stable density values of 1420 kg/m3, having sufficient compressive strength of 3.3 MPa, and guarantee high heat-shielding properties in building structures.Conclusion. The developed design and the conducted studies made it possible to establish the high efficiency of the proposed mixer, which provides a uniform distribution of the particles to be mixed, high homogenization and the creation of conditions for accelerating the physicochemical interactions in the created mixture with subsequent mixing of the prepared mixture with water and the formation of the required internal structure of the created composites.
Разработка эффективных составов и получение теплоизоляционных материалов с высокими теплозащитными показателями актуальна и требует глубокого изучения. В статье изложены результаты оптимизации состава теплоизоляционного раствора, приготовленного на композиционном вяжущем, вспученного вермикулита как заполнителя и различных функциональных добавок. Приведены результаты оптимизации состава вяжущей композиции на основе портландцемента и вермикулита суперпластификатором MELMENT F10. Установлена оптимальная дозировка суперпластификатора, обеспечившая плотность композиционного вяжущего 1933 кг/м3 при прочности 58,2 МПа. Подобраны функциональные добавки для обеспечения требуемых физико-механических и эксплуатационных свойств теплозащитного раствора. Изучено влияние на плотность и прочность состава теплоизоляционного раствора различных дозировок порообразователя Esapon 1214, суперпластификатора Melment F10, редиспергирующего порошка Vinnapas LL 4042 H. Получено уравнение регрессии для средней плотности и средней прочности теплоизоляционных растворов. Полученные уравнения регрессии и номограммы, построенные по ним, позволяют оптимизировать технологический процесс и эффективно им управлять. Методом математического планирования эксперимента подобран состав теплоизоляционного раствора, имеющий минимальное значение по плотности 490 кг/м3 при прочности на сжатие 2,3 МПа. В ряду современных штукатурных смесей для теплоизоляционных штукатурных растворов разработанные составы характеризуются улучшенными теплотехническими свойствами при оптимальных технико-экономических показателях.
The article presents the results of studies of granular materials obtained by non-firing technology. For the formation of granules, composite cement and magnesia binders containing waste products of expanded perlite and expanded clay are proposed. Mechanical activation of composite binders intensifies the processes of hydration and structure formation, contributes to increasing the strength of materials. The combination of a binder with a filler in the form of waste from the production of porous aggregates ensures a decrease in the density of the binder, the formation of a finely dispersed porous structure of the composite material, the formation of stable hydrates. The porous structure of the granules is provided by the use of porous sand to form the core of the granules. Studies of the structure of granules by electron microscopy revealed that the reliable adhesion of particles of porous sand with a composite binder stone provides high strength of porous granular materials. Cement granules based on expanded perlite sand are characterized by a density of 300 – 400 kg/m3 and a compressive strength of 1.8 – 2.6 MPa. Magnesia granules based on expanded clay sand have a density of 450 – 500 kg/m3 and compressive strength of 3.5 – 5.7 MPa. The work is aimed at creating effective building materials using resource-saving technology, at the rational use of production waste.
Introduction. In recent years, there has been an active development of 3D additive technologies. This trend could not but affect the construction industry. However, printing using plastics and other organic compounds differs significantly in its technological features from printing with building compounds. Concrete and mortars used in layer-by-layer printing must have a number of technological properties, such as sufficient viscosity for extrusion by an extruder, low mobility to maintain geometry after laying, high setting speed and strength after hardening. Currently, there are a number of compositions that meet these requirements, however, they, as a rule, are not distinguished by high strength and require a wide raw material base, which may not be available in field printing conditions. As a result, it is necessary to expand the range of building materials for 3D printing, suitable for the above criteria, as well as satisfying economic indicators.Materials and methods. Research has been carried out using physical and mechanical tests, X-ray phase analysis and electron microscopy on the effect of finely ground mineral additives on the microstructure and hardening processes of composite binders with various dosages of functional additives.Results. The results of studies on the production of composite binders for 3D additive technologies using Portland cement and man-made waste - waste of wet magnetic separation of the Stary Oskol electrometallurgical plant, modified with additives accelerators (Technonikol Master) and plasticizers (Polyplast PK-R) using mathematical planning and construction of mathematical models for composite binders with different hardening times are pesented.Conclusion. The efficiency of using the obtained composite binder has been proven, the use of which provides an increase in rheological properties, and also makes it possible to save expensive portland cement.
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