Toughening of requirements to buildings’ power efficiency enables development and implementation of modern lightweight concretes on efficient porous aggregates into building industry. The key demands to both lightweight heat-insulating and to fine concretes are ensuring low density index and thus low thermal conduction with high durability provided. There has been developed a lightweight heat-insulating fine concrete mix with the use of three fractions of granulated foam glass. To conduct the research there has been used a central composite design, which helped determine optimal consumption of separate fractions of granulated foam glass, and acquire a lightweight heat-insulating fine concrete with the lowest density. On the basis of obtained research results there has been carried out a calculation of thermal conduction ratio with the use of empirical formulae. The research results have been analyzed, and their descriptive statistics have been presented as diagrams and graphs. On the basis of the analysis of the research results there have been obtained regression equations and established influence degree of separate fractions of granulated foam glass on the density and thermal conduction ratio. There has been carried out an optimization of the material mix and the correlation between fine aggregate fractions calculated to provide the lowest average density.
Keywords: fine concrete, granulated foam-glass, thermal conduction ratio, average density, durability, experiment design, regression, mix optimization
The article presents aspects of the development of a device for wirelessly picking up a vibration acceleration signal from the surface of a ball mill drum. The results of measuring vibration acceleration for a ball mill model for various levels of loading with crushed material are presented. According to these results, with an increase in the load of crushed materials relative to the ball, the level of vibration decreases. The work also presents the obtained pie diagrams of the distribution of vibration load across the mill drum, from which one can judge its current operating mode.
Keywords: ball mill, wireless signal, vibration acceleration, mill loading control
The article presents an approach to the development of a case-based decision support system for assessing the safety of a section of a city's transport system. To store the database of precedents, it is proposed to use an OWL ontology. The use of the ontological approach allows a more accurate interpretation of the subject area, and over time will expand and supplement information about the precedent. The precedent structure is defined. The ontology architecture is given: classes, properties and instances. An example of filling the ontology with precedents is given, using the example of the city of Volgograd. Measure of proximity to compare precedents is proposed. The procedure for adding new precedents to the knowledge base is considered. With the help of the developed decision support system, it is possible to assess the safety of both individual road sections and the entire transport infrastructure of the city.
Keywords: ontology, reasoning by precedents, transport, transport security
The article discusses the prospects for the development of the combined technology of expanded fiber gypsum material. Based on the literature data, the optimal boundaries of the components were determined. To obtain the optimal composition, complete two-factor experiments were performed with changes in each factor at three levels. The results of the tests were obtained, on the basis of which regression equations were constructed, allowing to predict the characteristics of the resulting material, for the selection of the optimal composition.
Keywords: expanded gypsum, fibrogyps, fiber, strength, density