Concrete paving slabs for road construction are made from mixtures consisting of hydraulic binder, fine and coarse aggregates and water. The prepared mixture of a given humidity is subjected to vibration molding under the following technological conditions: process duration 5–10 seconds, vibration frequency 30–50 Hz and pressure 70–80 kg/cm2. Hardening of freshly molded samples is carried out in a heat and humidity treatment chamber. It has been established that it is possible to replace natural coarse aggregate with fractionated scrap concrete. The compressive strength of concrete with aggregate based on recycled crushed stone is 300 - 400 kg/cm2, water absorption 4.8 - 6.2%, frost resistance F2 200 - 300. The proposed technology allows solving both economic and environmental issues for regions with large amounts of concrete scrap at temporary industrial waste storage sites.

Keywords: concrete mixture, vibroforming, modifiers, filler, waste, concrete scrap, strength

This article deals with the problem of analyzing and recognizing human emotions using sound data processing. In view of the increase in the scope of application, which is largely caused by the difficult epidemiological situation in the world, the solution of the described problem is an urgent issue. The main stages are described: the audio data stream is recorded and, in accordance with the “sound fingerprinting” approach, is converted into an image that is a spectrogram of the sound data set. The stages of training a convolutional neural network on a pre-prepared set of sound data are described, and the structure of the algorithm is also described. To validate the neural network, a different set of audio data was selected, not participating in the training. As a result, graphs were constructed demonstrating the accuracy of the proposed method.

Keywords: neural network; human emotion recognition; convolutional neural network; sound fingerprinting; Tenserflow; Keras; Matlab; Deep Network Toolbox

Relevance and goals. The article describes a project in the field of solving the problem of managing organizational systems through the development of a system for remote monitoring and control of spatially distributed objects using LoRa network technology. Materials and methods. The project provides testing and practical use of LoRa networks. The developed system consists of 3 main modules: Devices, server part, and client application. In turn, devices are divided into gateways and end devices. Results. An automated system for managing spatial objects was designed, gateway devices and end devices that form a prototype of the Internet of Things network were developed and tested, as well as the server part of an automated system for remote control of spatially distributed devices. Conclusions. The system was tested and debugged, and a streamlined system for remote monitoring and control of spatially distributed objects was obtained based on the concept of the Internet of Things using LoRa network technology. It is assumed that the results of R&D will be in demand in organizations whose activities involve the use of spatially distributed resources.

Keywords: Internet of things, management of geographically distributed systems, LoRa networks, geosystem approach, spatial data infrastructures

In the article there was considered a possibility of off-grade materials utilization for making fine concrete with a multicomponent complex additive applied. Use of fine sands as raw material for fine concretes is actual for many regions in Russia because of deficiency of sands of necessary fineness modulus. There was considered the issue of utilization of fine sand and stale cement for reducing cost (loss), widening materials’ assortment for low-rise building, and energy- and resource-saving. To achieve the assigned purpose a multicomponent complex additive was applied. The research was carried out in full correspondence with the adopted design of the fractional factorial experiment. The acquired results were subject to a preliminary analysis and processing, and consequently dependences of strength properties upon varying factors were obtained. The obtained dependences made it possible to select optimal ingredients’ proportion of the complex modifying additive in order to increase strength properties of fine concrete based on off-grade materials. It was established that the use of optimal consumption of the complex additive components allows increase strength properties by 25-30% in comparison with the reference composition.

Keywords: fine concrete, fine sand, stale cement, complex additive, fractional factorial experiment, strength

This article presents a new developed calculation methodology, which includes provisions for standard calculations and takes into account the peculiarities of the operation of eccentrically compressed reinforced concrete structures operating at large eccentricities of load application. Adjustments have been made to the calculation methodology to take into account the following factors: the standard methodology uses the maximum tensile strength of reinforcement; proposals have been developed to determine the actual resistance of tensile reinforcement, which, in fact, will be significantly lower than the limit. Proposals are given that take into account the limiting deformations of concrete, which, in turn, will be a key quantity for determining the resistance of tensile reinforcement in the cross section. The article also presents the results of experimental studies of a flexible reinforced concrete pillar operating with a load eccentricity equal to e0 = 0.32h. Theoretical calculations and experimental studies were analyzed and appropriate conclusions were drawn.A formula has been developed to determine the real resistance of the stretched metal reinforcement at the time preceding destruction. The calculation algorithm has been compiled. When comparing theoretical and experimental strength, the difference did not exceed 5%.

Keywords: steel, heavy concrete, reinforced concrete, testing, stand

The article gives an insight into the traditional passive cooling techniques utilized in Mediterranean and hot climate regions, showcasing the effectiveness of natural ventilation and central patios in improving indoor thermal comfort and reducing energy consumption. The integration of these traditional design elements with modern technologies is crucial for creating environmentally friendly and culturally significant architectural solutions for the future. The discussion then transitions to the importance of energy efficiency and environmental sustainability in modern building design, highlighting the use of Ansys Fluent software for modeling natural ventilation in a residential apartment in Yemen. The article emphasizes the need for engineering and architectural solutions to achieve high performance in energy efficiency and environmental safety in contemporary construction practices.

Keywords: natural ventilation, Yemeni houses, Spalart-Allmaras model, civil engineering, Ansys Fluent

The drilling and blasting method is currently the most widely used for mining rocks. An indicator of the high–quality drilling and blasting operations is the uniform granulometric composition of the exploded rock mass - the percentage of oversized ore pieces should be minimal. The percentage of oversized and its increase have a significant impact on the technical processes of transporting rock mass, leading to an increase in the costs of loading and transportation operations and secondary crushing of oversized ore masses. The paper describes the results of a study of methods for determining the granulometric composition of drilling and blasting operations using neural networks of segmentation Unet and FPN. Images taken from UAVs are used for analysis. A method of classifying ore by size has also been developed, which ensures the accuracy of the proportion of correct answers of more than 0.91. The expected result of the introduction of the system for automatic determination of the granulometric composition of drilling and blasting operations is the possibility of more accurate control over the quality of their performance.

Keywords: granulometric composition, Unet, FPN, classification, segmentation

In order to negate the loss of strength, that can lead to collapse of constructions, we should take measures to prevent cracking. Every crack emersion in reinforced concrete indicates that the accumulated stress has been released in this area of the structure. The cause of cracks are internal tensile stresses that can occur due to internal processes in the element and from external loads on the structure. It is possible to eliminate cracks that have already appeared with the help of repair compounds that fill the volume of cracks in various ways. Injection, as one of the solutions, will help to maintain the strength and durability of the structure.

Keywords: cracking, concrete, reinforced concrete slab, crack, defect, deformation, strength, soil, repair compound, foundation, foundation slab, injection

This article discusses the possibility of changing the formulation of an anti-icing mixture directly in a combined road machine, by integrating data from road weather stations and modernizing a universal spreader. To quickly change the recipe of the distributed mixture, using the example of a sand-salt mixture, it is proposed to use a two-hopper universal spreader with an automated control system. The recipe for the distributed anti-icing mixture is calculated depending on weather conditions. An example of LabVIEW software is given to solve the local problem of finding a current weather station.

Keywords: automation, road machine, universal spreader, de-icing materials, composition selection, control system

Methods for calculating technological and functional tolerances in the manufacture and installation of steel structures are described. An experimental installation of the structure was carried out to make it possible to clarify the tolerances, and the foundations of the methodology for assessing the qualitative and quantitative manufacturability of assembly elements were put forward to simplify the processes of manufacturing and assembling the structure.

Keywords: methods for calculating tolerances, installation of a structure, manufacturing of structures, manufacturability, complex indicator of manufacturability

With the development of technology, access systems with higher accuracy and levels of reliability have emerged. Access systems are a fascinating and important area of expertise, requiring knowledge from a wide range of disciplines such as information security, electronics, programming and systems administration. Therefore, its further development requires highly qualified specialists. In this regard, to involve the younger generation, educational programs and courses aimed at training and intellectual development of adolescents are appearing. To practically reinforce the acquired knowledge, various educational kits and open-source laboratory stands are used, on which students can try their hand and implement ideas. This project has prospects for further development for work not only in terrestrial laboratories, but also at orbital stations - this aspect is especially interesting for young explorers of the Universe. The goal of the work is to create a safe and convenient access system for users, providing a high level of security and ease of use.

Keywords: research, experiment, payload, space, remote control, self-determination, career guidance

The stages of pre-project and design preparation are fundamental for the further implementation of the investment and construction project. The success of construction and commissioning of facilities depends on the successful completion of these stages. The duration of the stages depends on the competence and consistency of interaction between the participants in the investment and construction project, the rationality of decision-making by the technical customer (developer) and a number of other factors. Identifying factors and finding options for rational planning of the stages of pre-project and design preparation is very relevant. As part of the study, a formula was derived for determining the duration of the stages of pre-design and design preparation of objects for construction, taking into account the influence of negative factors. The results of the study are used in planning the stages of pre-design and design preparation of a facility for construction.

Keywords: factors, stages of pre-project and design preparation of objects for construction, duration of procedures

This article presents the results of a study of the filtration flow in a porous material based on a thrice periodic minimum surface (TPMP) Neovius. The Brinkman model was used to determine the profile of the fluid flow velocity in the channel containing the TPMP insert. Based on computational experiments in ANSYS Fluent, the dependence of the permeability of the medium on its porosity is determined. The results of the study can be used to describe filtration processes in the oil and gas industry, hydrogeology and other fields related to filtration flows in rocks and other media.

Keywords: permeability, filtration, porous medium, minimum surface, TPMP, ANSYS, Brinkman model, numerical modeling, boundary value problem, velocity profile

This article is devoted to the analysis of the application of the software and hardware complex of mixed reality and augmented reality ""BRIO MRS"" to explore the possibility of digitalization of the construction control process within the framework of JSC CITY - XXI Century. The article also discusses the specific application of mixed reality, which consists in checking the progress of work on the construction of a real building and its compliance with the designed digital information model using a hardware and software complex for augmented and mixed reality. The complex described in this article was actually used and is being used at the construction site. The paper describes the procedure for using a hardware and software complex to verify the compliance of the progress of construction work and the digital information model. The principle of operation of the complex, as well as the prospects that were discovered during the implementation of the experience of using a mixed and augmented reality system, are the subject of further research. In conclusion, based on the conducted research, it turns out what tasks the complex described in the article allows to solve, what advantages it has over analogues and what advantages its introduction into the activities of a modern development company will bring.

Keywords: mixed reality, augmented reality, digitalization, digital information model, modern standards, hardware and software complex, construction control

The article discusses the issues related to the solution of an actual problem – the recycling of accumulations of plastic waste in the ocean. It is proposed to organize the plastic recycling process directly in the ocean on recycling vessels. At the same time, the products of mechanical processing and pyrolysis can be used to support the construction, road construction, and electric power industries of coastal developing countries in Africa and Latin America, near which the largest amount of plastic waste is concentrated. It is proposed to use both systems with artificial intelligence trained to recognize and identify plastic by shape, and systems based on spectral analysis of the composition of plastic for sorting and identification.

Keywords: plastic waste, microplastics, plastic recycling in the ocean, recycling vessel, plastic type recognition, use of recycled plastic