bluuebunny/crossref_metadata_2025 huggingface dataset:
Shock Induced Flow-Separation in Hypersonic Intakes at Off-Design Conditions
Authors: Singh Rachit , Sinha Krishnendu
Published: December 2023

High-speed turbulent flow in hypersonic intakes encounters flow-separation due to shockboundary layer interaction. Presence of separation bubble changes the pressure distribution over the surface which can lead to deterioration of aerodynamic performance of intake and thus jeopardize the stability of vehicle. In this study, we employ the physics-based shock-unsteadiness k-e model to compute separation bubble size in a mixed compression two-ramp intake. The design point Mach number of 6 at 30 km altitude with zero angle of attack is considered. Changes in separation bubble length is analyzed at different off-design conditions by varying the flight Mach number, angle of attack and cruise altitude. The changes observed in the separation length by variation of above flight parameters is studied in terms of the physically relevant canonical parameters of upstream Mach number, Reynolds number Red and the ratio of wall to recovery temperature. CFD simulations are performed for the entire range of canonical and flight parameters. Wall-to-recovery-temperature ratio is found to be an important governing parameter for separation length studies. The largest shock-induced separation is observed for the case of off-design flight Mach number of 8. The corresponding effect on the lift and drag generated by the hypersonic intake are quantified.
Flow Field Investigation on a Double Delta Wing
Authors: Biswas Samrat , Roy Aritras , Roy Animesh , Majumdar Bireswar , Kumar Prabir
Published: December 2023

In this paper flow field characteristics of double delta wing have been studied both experimentally and numerically at different angles of attack ranging from 0° to 30° at a Reynolds number of 2 x 105 based on the root chord length of the wing model. Surface oil flow visualization has been studied on the leeward surface of a sharp edged single beveled 76°/40° cropped double delta wing at subsonic wind tunnel facility. The flow physics is further validated with the help of surface pressure measurement in the context of surface flow pattern. Subsequently CFD (Computational Fluid Dynamics) analysis is carried out using ANSYS Fluent. Comparisons of both qualitative as well as quantitative measurement with experimental techniques and computational work have been carried out. For computational work, the computational domain is meshed with unstructured grids and SA-turbulence model is used.
Airfoil Optimisation at Ultra-Low Reynolds Number
Authors: N. Varsha  , Deshpande M. D , Sivapragasam M.
Published: December 2023

In recent times micro-air vehicles are utilised for various civilian and military applications. Because of their small size and low flight speeds they fly in the low Reynolds number (Re) regime. At such low Re the aerodynamic characteristics, most importantly the lift-to-drag ratio (Cl/Cd), are deteriorated. An improvement in (Cl/Cd) can lead to enhanced vehicle performance. The aerodynamic improvements can be achieved by optimising the wing profile geometry. In the present paper, optimisation of an airfoil is done to maximise (Cl/Cd) at Re = 1000. The upper and lower surfaces of a modified NACA 2408 airfoil are parametrised using the Akima interpolation method. The fixed-direction set method is used in optimising the airfoil aerodynamic performance with six control points each on the upper and lower surfaces. A corrugated airfoil, with a trapped vortex within it, is obtained as a result of this optimisation. Further, optimisation is carried out only on the upper surface of the corrugated airfoil with flat lower surface by increasing the number of control points from six to ten. (Cl/Cd)max is 3.718 for the baseline airfoil, while the final optimal airfoil resulted in (Cl/Cd)max of 4.670, a 25.6 % increase.
An Alternative Reynolds Shear Stress Model and Wake Model for a Flat Plate Boundary Layer Flow
Authors: Phani Kumar P. , Dey J.
Published: December 2023

The well-known closure problem has led to many models for the Reynolds shear stress. But many of these models are based on the Boussinesq approximation involving the mean velocity gradient and an eddy viscosity, which, however, requires to be modeled. Here, for a steady, incompressible and constant-pressure boundary layer, the Reynolds shear stress is expressed as a product of the mean velocity and the local momentum-deficit. This closure model is then incorporated in the boundary layer equation for the outer layer to predict the streamwise velocity in the wake region.
Estimation of Responses of Spacecraft to High Frequency Shock Loads and Comparison with Test Results
Authors: Premkumar D. , Patnaik M.N.M. , Renji K.
Published: December 2023

To arrive at shock levels for the equipment of spacecraft, one needs to have a suitable analytical prediction model. One of the prediction techniques is explicit time integration of the governing equation of motion. This methodology is in use for determining the responses due to an impact where the force of impact is known. But they have not been applied to spacecraft where the force is not known, but the accelerations are known. Also, the frequency range of interest covers higher order modes. In this work theoretical estimation of response of spacecraft to high frequency shock excitation is attempted using an explicit time integration scheme. The parameters required for the response estimation are first established. The influence of dynamic relaxation parameter on the estimated responses is discussed. The acceleration responses of two typical spacecraft are measured during their separation from the vehicle adaptor. The responses are theoretically estimated using the parameters established in this work. In both the spacecraft the estimated results are in very good agreement with the measured results with some differences seen at locations far away from the source.
Two Parameter Model for Joint Stiffness Identification in a Single Lap Jointed Structural Assemblies Using Sub-Structure Synthesis
Authors: Ingole Sanjay B.
Published: December 2023

Many mechanical structures are composed of substructures connected together by joints such as bolts, welds, rivets etc. The added flexibility introduced by the joint to the structure has significant effect on the static and dynamic behavior of the structure and must be accurately modeled. This fact clearly indicates that the analyses will not properly model the dynamic behavior of the structure if the joints cannot be accurately identified. This has prompted the researchers to include the effect of joint stiffness in the structural model and to estimate the stiffness parameters using inverse dynamics. In the present work, single lap joint has been modeled as a pair of translational and rotational springs and frequency equation of the overall system has been developed using sub-structure synthesis. The validity of the proposed method is demonstrated; only first few natural frequencies of the composite system is required to estimate unknown joint stiffness parameters.
Design and Fabrication of a Test Rig to Determine Helium Permeability through Fabrics
Authors: Tanwar Lovin , Pant Rajkumar S.
Published: December 2023

The fabric of a Lighter-Than-Air (LTA) system experiences permeation of Helium over a period of time. Due to the small size of the molecules of Helium, it permeates through the intermolecular spaces of the fabric. This leakage increases with time due to the degradation of the fabric. LTA systems need to be deployed for long durations. The loss of Helium due to permeation reduces the relative lift of the LTA system. The unknown permeation rates thus lead to uncertainties in the deployment time of the system. This paper describes the design and fabrication of a test rig to determine the permeability of Helium through different fabrics. This method involves a permeation cell divided into upper and lower chambers arranged to hold a specimen fabric between them, with the provision of a continuous supply of Helium in the lower chamber. A Phoenix L300i Helium Leak Detector (HLD) is connected to the upper chamber to detect Helium and measure its concentration. The further objective of this research is to study the variation of helium permeability through the fabrics at constant temperature and input pressure with time.
Development of Indigenous Helicopters in India - Historical Perspective, Challenges and Future Potential
Authors: Vijaya Kumar M.
Published: December 2023

In independent India, design and manufacturing of aircrafts is intricately linked to Government labs and Defence Public Sectors. In case of fixed wing aircrafts, there are more than one design agencies in addition to Hindustan Aeronautics Limited (HAL), such as ADA, DRDO and NAL. However, in case of rotary wing aircrafts, HAL is the only company involved in the design and development of helicopters.This paper is an attempt to chronicle the journey of HAL, from a licence producer of helicopters starting in 1964 to becoming a key player in design and production of indigenous helicopters. The journey had its ups and downs, trials and tribulations, leading to success. The paper addresses the Design and manufacturing challenges faced during the development.

That HAL rolled out its 300th production helicopter of Advanced Light Helicopter (ALH) in September 2020, bears testimony of its perseverance. Presently, HAL has come a long way and has emerged as a major company in India which is capable of design, development, testing, integration and certification of indigenous helicopters and augmented with capability in production, maintenance, repair and overhaul of helicopters. The experience reveals that indigenous design and development has its own share of uncertainties and risks and hence will suffer from time over run due to inexperience, design iterations, performance issues, lack of manufacturing capabilities and limitations in eco-system etc. while bringing out first product. However, things improve with consecutive products. The hard truth is that the only path left to the developing countries, is to start the design (if required with design consultancy from abroad), make sincere efforts to learn through mistakes, sweat it out and improve the product.
Airborne UAV Remote Sensor Position Accuracy Algorithm in Catastrophes Zones
Authors: Pawar Vipinkumar Rajendra , Mande Sudhakar S. , Rizvi Imdad
Published: December 2023

Sensor payload calibration and FOV are still the most essential parameters in Airborne Remote Sensors for developing quality terrain images in the Remote Sensing field. UAVs are core devices in Airborne Remote Sensing by carrying camera payload for large terrain objects to achieve desired image quality with geographical position provided for different available flight planning algorithms.

This paper proposes the algorithm to find the exact Geo-coordinates for UAV navigation algorithm viewpoint identification for implementing Airborne Remote Sensing (ARS) to study Landslide Susceptibility Zone as well as application for catastrophe analysis. Terrain Slope and Aspect was considered using Remote Sensing products from ISRO CartoSat and NASA ASTER satellite available in the Digital Elevation Model (DEM) construction to maintain the calibrated angle of vision, field of vision, and land surface image quality.

This algorithm will enhance the functioning of various available UAV Flight Planning Algorithms to improve the quality of 3D topography images for 3D Modeling as well as Landslide and Flood Prediction and Analysis, as well as provide the position of camera payload and tilting angle for enhanced terrain images.
RESEARCH OF TECHNOLOGICALLY VALUABLE BAKER’S YEAST STRAINSOF ARMENIA
Authors: Bagiyan Valeri , Chitchyan Karine , Kinosyan Marina , Khachaturyan Nune
Published: December 2023

The study is devoted to the study of the biological characteristics of strains of baking yeast Saccharomyces cerevisiae of Armenia, as well as the effect of long-term maintenance (1996-2021) in laboratory conditions on their enzymatic activity.
FEATURES OF DRUG TREATMENT FOR PARKINSON'S DISEASE
Authors: Shiraliyeva R.K. , Aliyeva F.N. , Mammadova M.M. , Mammadbeyov F.N.
Published: December 2023

The article provides information about a study that studies the features of drug treatment of patients with Parkinson's disease among the population of the capital of Azerbaijan Republic- Baku. The study is based on data from 703 patients with Parkinson's disease diagnosed in outpatient clinics in Baku by the beginning of 2019. In the treatment of Parkinson's disease, all modern treatment options were used (Dopamine receptor agonists, Levodopa drugs, Antixolinergik drugs, COMT inhibitors, NMDA receptor antagonists, etc.). According to the study results, the standard approach is used in the treatment of Parkinson's disease in Baku, but in most cases, polytherapy is preferred (59.2±1.9 per 100 patients). In terms of frequency of use in treating Parkinson's disease, the first two places are occupied by dopamine precursors (63.2±1.8 per 100 patients) and dopadecarboxylase inhibitors (59.2±1.9 per 100 patients), respectively. Among the drugs used for the treatment of Parkinson's disease, Nakom (28.2±1.7 per 100 patients) and its combination with Cyclodol (10.4±1.2 per 100 patients) and Akineton (10.1±1.1 per 100 patients) prevail. Monotherapy is carried out only with Pronoran and Cyclodol (17.1±1.4 and 10.7±1.2 per 100 patients, respectively).
EVALUATION OF THE EFFECTIVENESS OF ALCEBA IN CHILDREN WITH CEREBRAL PALSY BASED ON POTENTIAL INDICATORS OF COGNITIVE IMPAIRMENT
Authors: Madjidova Y.N. , Mukhammadjonova D.M. , Isakova G.S.
Published: December 2023

We examined 72 patients with cerebral palsy at the age of nine to 17 years (mean age 11.33±2.1 years), of which 29 were girls, 43 were boys. Neuropsychological tests were performed (British Picture Vocabulary Scale (BPVS) test for verbal intelligence, Raven's test (Raven Progressive matrices) - to assess non-verbal intelligence and cognitive evoked potentials (CEP). In cerebral palsy, cognitive impairments in the form of disorders of memory, attention, thinking, verbal and non-verbal intelligence, and P300 cognitive evoked potentials tend to deteriorate, conditionally, with an increase in paretic limbs. In addition, the course use of the drug memantine (alcheba) in patients with cerebral palsy has a curative effect on cognitive impairment in this category of patients.
High efficiency of road structures through the integrated reinforcement of soil and development of innovative concrete
Authors:  Адигамов Р.Р. ,  Митюкова Е.В. ,  Соловьева В.Я. ,  Гунин С.О.
Published: December 2023

Установлено, что гранулированный доменный шлак улучшает структуру проблемных связных грунтов, повышая их плотность и прочность. Показано, что при использовании тонкомолотого гранулированного доменного шлака (ТГДШ) в сочетании с портландцементом (ПЦ) обеспечивается эффективное укрепление грунтов разной природы, особенно значительное в присут­ствии комплексной химической добавки «ПРА» на поликарбоксилатной основе. Введение ТДШ в бетон в сочетании с ПЦ и в присут­ствии двух комплексных химических добавок «ПРА» и «Наноактив-М» на основе поликарбоксилатов разной природы позволяет создать инновационный материал с техническими показателями, обеспечивающими его высокую долговечность, который целесообразно рекомендовать для дорожных покрытий.

It has been established that granulated blast-furnace slag improves the structure of the problem cohesive soils increasing their density and strength. It was shown that the use of fine ground granulated blast furnace slag (GGBFS) in combination with Portland cement (PC) provides effective strengthening of soils of different nature, especially significant in the presence of the complex chemical additive "PRA" on a polycarboxylate basis. The introduction of GGBFS into concrete in combination with PC and in the presence of two complex chemical additives "PRA" and "Nanoaktiv-M" based on polycarboxylates of different nature allows creating an innovative material with technical characteristics that ensure its high durability, which is advisable to recommend for road pavements.
Intrinsic deformations of cement-ash stone
Authors: Овчаренко Г.И. , Хижинкова Е.Ю.
Published: December 2023

Исследование проведено с целью изучить влияние высококальциевой золы (ВКЗ) тепловых электростанций, имеющей различные состав и свойства, на собственные деформации образцов цементно-зольного камня, твердеющих в автоклаве под давлением 2,1 МПа или при пропаривании. Установлены статистически значимые одно-, двух- и трехпараметрические модели взаимосвязи деформаций камня с изменением состава ВКЗ. Наибольшие коэффициенты корреляции отмечены для зависимостей деформации от содержания свободной извести, свободного оксида магния и серного ангидрида при их совместном присутствии в составе золы. Предложена методика выявления деструктивно-опасных зол и подбора оптимальных составов золоматериалов.

The aim of the research was to study the influence of high calcium ash (HCA) of thermal power plants of different composition and properties on deformation of cement-ash stone hardening in the autoclave with steaming under a pressure of 2.1 MPa. Statistically significant one-, two- and three-parameter models of interrelation of brick deformations with changes in the composition of HCA have been established. The highest correlation coefficients are observed for deformation dependences on the content of free lime, free magnesium oxide and sulfuric anhydride when they are jointly present in ash. A method of identifying ashes presenting a hazard of destruction and selecting the optimum compositions of ash materials is proposed.
Strengthening of cement by the introduction of fine mineral additives
Authors:  Ильина Л.В. ,  Гичко Н.О. ,  Туляганов А.К.
Published: December 2023

Ввод исследованных тонкодисперсных минеральных добавок в состав портландцемента приводит к повышению прочности цементного камня как при твердении в стандартных условиях, так и после тепловлажностной обработки. Оптимальное содержание тонкоизмельченного диопсида составляет 7 %, тонкоизмельченного известняка —  1—3 %, комбинированной добавки (при соотношении компонентов известняк: диопсид, равном 1 : 2) —  7 % массы портландцемента.

The examined fine mineral additives introduced into Portland cement increase the strength of cement both during its hardening in standard conditions and after heat and moisture treatment. The optimum content of fine diopside is 7%, fine limestone - 1-3%, combined additive (with the limestone: diopside ratio 1: 2) - 7% of the weight of Portland cement.
Colloidal additive based on aluminosilicate minerals for cement modification
Authors:  Урханова Л.А. ,  Доржиева Е.В. ,  Гончикова Е.В. ,  Цыденова А.Б.
Published: December 2023

В статье представлены результаты исследований в рамках получения коллоидной добавки на основе алюмосиликатных пород для модификации цементного камня. Установлено, что на основе сынныритов Республики Бурятия можно получать коллоидный модификатор с использованием золь-гель-технологий. В результате экспериментов установлены способ получения коллоидной добавки и ее оптимальные дозировки, проведен анализ гидратации цемента в присутствии коллоидного модификатора. Предел прочности при сжатии цементного камня с добавками во все сроки твердения выше, чем у контрольных образцов. Максимальные значения прочности, достигнутые образцами цементного камня в возрасте 28 сут, — 82—90 МПа.

The paper presents the results of the research in obtaining a colloidal additive on the basis of aluminosilicate minerals for cement modification. It was found that on the basis of synnyrites of the Republic of Buryatia one can receive a colloidal modifier with the use of sol—gel technologies. As a result of experiments the method of obtaining a colloidal additive and its optimal dosages have been established, the analysis of cement hydration in the presence of the colloidal modifier has been carried out. The compressive strength of cement with additives in all periods of hardening was higher than that of the control samples. The maximum strength achieved by cement samples at the age of 28 days was 82—90 MPa.
Coloring finishing coatings for silicate materials based on the technological wastes of the factories of the Republic of Belarus
Authors:  Лобачевский В.И. ,  Губская А.Г. ,  Воловик Т.В. ,  Письменский П.И.
Published: December 2023

Статья посвящена актуальной проблеме переработки техногенных отходов, образующихся на предприятиях Республики Беларусь. Приведены результаты исследований, направленных на получение силикатного связующего, основного компонента окрашивающих покрытий на основе кремнегеля —  отхода производства фтористого алюминия безварочным способом. На основе экспериментальных данных установлена возможность получения окрашивающих отделочных покрытий для различных типов силикатных материалов с использованием техногенных отходов в качестве наполнителей и красителей.

The article is devoted to the actual problem of reprocessing the man-made wastes formed at the factories of the Republic of Belarus. The results of the research aimed at obtaining a silicate binder, the main component of coloring coatings based on silica gel — a waste product of aluminum fluoride production by no-bake method are given. On the basis of experimental data the possibility of obtaining coloring finish coatings for different types of silicate materials using man-made wastes as fillers and colorants has been established.
On the issue of water bleeding of cements
Authors: Шахова Л.Д. , Коновалов В.М.
Published: December 2023

В статье рассматриваются проблемы водоотделения на разных масштабных уровнях. Отмечается, что проблемы отделения воды в бетонных и растворных смесях на микро- и нано-уровнях остаются самыми сложными для исследования и регулирования. Рассматриваются некоторые факторы, относящиеся к технологии производства цемента и бетонных смесей, влияющие на водоотделение.

The article deals with the problems of bleeding at different scale levels. It is noted that the problems of bleeding in concrete and mortar mixtures at micro- and nano-levels remain the most difficult to study and regulate. Some factors relating to the technology of cement and concrete mixes production affecting bleeding are considered.
Structural and rheological properties of cement powder
Authors:  Шахова Л.Д. ,  Черноситова Е.С. ,  Щелокова Л.С. ,  Уханева Н.Г.
Published: December 2023

Структурно-реологические свойства цементного порошка существенно влияют на продолжительность работ и трудозатраты в ходе транспортирования и отгрузки цемента. Это обусловливает актуальность задачи поиска механизмов управления такими свойствами. Статья посвящена исследованию основных факторов, влияющих на текучесть цемента. Приведены результаты ее статистического анализа в зависимости от тонкости помола цемента (по остатку на сите № 008 и удельной поверхности по Блейну), влажности, насыпной плотности и плотности в максимально уплотненном состоянии, а также показана взаимосвязь производственных факторов и текучести цемента. Корреляционнорегрессионным методом анализа установлено, что на текучесть цементного порошка влияют удельная поверхность и переменный фактор, роль которого пока не оценена количественно.

The structural and rheological properties of cement powder significantly affect the duration of work and labor costs in the course of transportation and ship-ment of cement. This makes the task of searching for the mechanisms of controlling such properties urgent. The article is devoted to the study of the main factors influencing the flowability of cement. The results of the statistical analysis depending on the fineness of cement grinding (by the rest on the sieve No. 008 and the Blaine specific area), moisture content, bulk density and the density in the maximum compacted state, as well as the interrelation of production factors and the cement flowability were shown. The correlation-regression method of analysis established that the specific area and a variable factor, whose role has not yet been quantified, affect the flowability of the cement powder.
Metallurgical slags as a mineral additive in cement production
Authors:  Сивков С.П. ,  Турушева Е.В. ,  Мошковская С.В. ,  Крылов А.П.
Published: December 2023

С целью снижения углеродного фактора в состав цементов вводят большое количество минеральных добавок, что зачастую приводит к резкому падению его прочностных свойств. В качестве добавок обычно используют активные (доменные гранулированные шлаки, пуццоланы, золы) или инертные (известняк) минеральные добавки. В данной работе была показана принципиальная возможность использования закристаллизованных сталерафинировочных шлаков, содержащих значительное количество гидравлически активных фаз — ​алюминатов и силикатов кальция — ​в качестве реакционно-активной минеральной добавки, улучшающей физико-механические свойства цемента.

In order to reduce the carbon factor a lot of mineral additives are used in cements, which often leads to a sharp fall in its strength. Active (granulated blast furnace slag, pozzolans, ash) or inert (limestone) minerals are usually used as additives. This work showed the principal possibility of using crystallized steel refining slags containing a signifi-cant amount of hydraulically active phases, calcium aluminates and silicates, as a reaction-active min-eral additive improving physical and mechanical properties of cement.
Limestone Calcined Clay Cement (LC3)
Authors: Майти С.
Published: December 2023

Цемент с низким углеродным следом, или цемент с известняком и кальцинированной глиной (limestone calcined clay cement, LC3), представляет собой трехкомпонентный композиционный цемент с долей клинкера в цементе всего лишь 0,40. Синергетический эффект при гидратации клинкера, прокаленной глины и измельченного известняка позволяет достичь свойств материала, которые сопоставимы со свойствами цементов, выпускаемых промышленными предприятиями. В смешанных цементах с низким углеродным следом кальцинированная глина играет роль пуццоланы, позволяющей снизить долю клинкера. Основное сырье для изготовления LC3 — каолинитовые глины. Требуемые для этого свойства имеют глины, содержащие более 35 % каолина. Распространен миф о том, что природные запасы каолинитовых глин весьма ограничены. Согласно исследованиям и технико-экономическим обоснованиям, в Африке, Азии и на других континентах существуют огромные залежи каолинитовых глин — более 1 млрд т. В России и других странах СНГ также есть месторождения каолинитовых глин, вполне пригодных для изготовления LC3. Для их производства не требуется строить новые заводы «с нуля». Весь технологический процесс легко интегрировать в существующую производственную систему, нужно только установить вращающуюся печь для тепловой обработки глины. Изготовление LC3 позволяет сократить выбросы CO2 на 40 % и использовать около 45 % сырьевых материалов, непригодных для использования в промышленности. В зависимости от производственных условий, выбора оборудования и расстояния перевозки глины изготовление LC3 может быть более чем на 25 % дешевле, чем производство обычного цемента.

Low carbon cement or limestone calcined clay cement (LC3) is a ternary blended Portland cement with clinker factor as low as 0.40. It uses the synergetic hydration of clinker, calcined clay and crushed limestone to achieve comparable properties of commercial cements. Low carbon cement blends use calcined clay as pozzolanic material lowering the clinker factor. The major raw material in the production of LC3 is kaolinitic clays. Clays with a kaolin content greater than 35 % has shown appreciable properties. It is a common myth that kaolinitic clays are not available abundantly. Studies and feasibility studies indicate massive deposits of kaolinitic clays or more than billion tons exists in Africa, Asia and other continents. There are also very suitable deposits in Russia and Commonwealth of Independent States of kaolinitic clays and can be used for production of LC3. No new greenfield plants are necessary to produce LC3. The entire production process can easily be integrated into the existing production system. The only additional requirement is a rotary calciner for calcination of clays. Production of LC3 saves upto 40 % of carbon emissions and uses around 45 % of non-commercial grade raw materials. Depending upon the production conditions, choice of equipment’s and distance of clay availability, production of LC3 can be more than 25 % cheaper than conventional cement production.
Indian cement sector – demonstrating circularity in production and consumption
Authors: Бадола А.
Published: December 2023

Индийская цементная промышленность растет быстрыми темпами, при этом большое внимание уделяется вопросам экологии. С перспективами дальнейшего быстрого роста этой отрасли, обусловленного развитием экономики страны и рядом других факторов, тесно увязаны прогнозируемое расширение использования в цементном производстве альтернативных видов сырья и топлива и другие меры, способствующие сокращению выбросов CO2.

India's cement industry is growing rapidly, with great emphasis on environmental issues. The projected increase in the use of alternative raw materials and fuels in cement production and other measures to reduce CO2 emissions are closely linked to the prospects for further rapid growth of the industry, due to the development of the country's economy and a number of other factors.
Super strong fiber concrete as an additional reinforcement layer in flexural reinforced concrete elements
Authors: Сапронов И.М. , Агеев А.В. , Забродин М.Е. , Браян Б.М. , Федоров М.В.
Published: December 2023

В статье описана новая эффективная технология усиления железобетонных мостовых конструкций при помощи добавленного слоя (добавленного верхнего слоя, ДВ) из сверхпрочного фибробетона (СПФБ). Приведены результаты экспериментального исследования образцов с ДВ при изгибе до их разрушения. Установлены конкретные значения степени усиления изгибаемых железобетонных конструкций при расположении ДВ как в сжатой, так и в растянутой зонах.

The article describes a new effective technology of strengthening reinforced concrete bridge structures by means of an added layer (added top layer, ATL) made of superstrong fiber concrete (SSFC). The results of the experimental study of samples with ATL in bending before their destruction are given. The actual values of the degree of strengthening of flexural reinforced concrete structures with the ATL located in both the compressed and tensile zones have been established.
On the mechanism of action of cement grinding aids
Authors:  Шахова Л.Д. ,  Котляров Р.А. ,  Черноситова Е.С.
Published: December 2023

В статье предлагается теоретическое обоснование механизма действия технологических добавок при помоле цемента, обусловленного снятием поверхностных электростатических зарядов. Установлена взаимосвязь между поверхностной проводимостью цементных частиц и классом органических соеди нений. С использованием статистических методов доказано влияние типа вводящейся добавки и минералогического состава клинкера на диэлектрическое сопротивление цементных частиц и текучесть порошка. Результаты эксперимента и масштабной промышленной практики согласуются с выдвинутым предположением о возможности снятия электростатических зарядов и регулирования текучести цементного порошка с помощью технологических добавок, склонных к поляризации.

The paper offers a theoretical substantiation of the mechanism of action of additives during cement grinding caused by the removal of surface electrostatic charges. The interrelation between the surface conductivity of cement particles and the class of organic compounds is established. Statistical methods were used to prove the influence of the type of the additive introduced and the mineralogical composition of the clinker on the dielectric resistance of cement particles and the fluidity of the powder. The results of the experiment and large-scale industrial practice are consistent with the proposed assumption about the possibility of removing electrostatic charges and regulating the fluidity of cement powder with the help of technological additives prone to polarization.
Use of semi-adiabatic calorimetry to evaluate the influence of formulation factors on the heat release kinetics of cement
Authors: Береговой В.А. , Лавров И.Ю.
Published: December 2023

С использованием полуадиабатической калориметрии разработана методика исследования процессов гидратации цементных композиций. Сконструирован прототип установки со съемными теплоизолирующими оболочками, обеспечивающий возможность моделирования условий твердения бетона в реальных конструкциях. Показана эффективность применения предлагаемой методики в решении прикладных задач, связанных с оценкой активности цементов и их функциональной совместимости с добавками.

A technique for studying the hydration processes of cement compositions has been developed using semi-adiabatic calorimetry. The pilot plant with removable heat-insulating shells, which provides the possibility of modeling the conditions of concrete hardening in the real structures, has been designed. The effectiveness of the proposed methodology in solving applied problems related to the evaluation of the activity of cements and their functional compatibility with additives is shown.
Investigation of strain hardening of hydration-hardening composites reinforced with dispersed polypropylene fibers
Authors:  Смирнова О.М. ,  Харитонов А.М. ,  Тихонов Ю.М.
Published: December 2023

В работе изучен характер разрушения дисперсно-армированных полипропиленовой микрофиброй композитов, определены их проч ностные и деформативные свойства при сжатии и растяжении при изгибе, установлены корреляционные зависимости между их составом и характеристиками диаграмм нагрузка— деформация. Применялись высокопрочная цементная матрица на основе портландцемента (предел прочности при сжатии 70 МПа) и матрица средней прочности на основе гранулированного доменного шлака со щелочной активацией (предел прочности при сжатии 40 МПа). Состав матрицы подбирался из условия максимальной подвижности при низком водоцементном отношении, составляющем 0,22 и 0,30 для высокого наполнения композита полипропиленовой микрофиброй в количестве 5 и 3,5 % для матриц на портландцементе и шлако-щелочном вяжущем соответственно. Диаграммы деформирования представлены для всех исследованных составов.

The paper describes the character of structural damage of composites reinforced with dispersed polypropylene microfibers, determines their strength and deformation properties under compression and tension in bending, and establishes correlation between their composition and characteristics of load-deformation diagrams. High-strength cement matrix on the basis of Portland cement (compressive strength limit of 70 MPa) and medium strength matrix based on granulated blast-furnace slag with alkaline activation (compressive strength limit of 40 MPa) were used. The composition of the matrix was chosen by the maximum mobility at a low water-cement ratio of 0.22 and 0.30 for high filling of the composite with polypropylene microfiber in the amount of 5 and 3.5 % for matrices on Portland cement and slag-alkali binder, respectively. The deformation diagrams are presented for all investigated compositions.
Ground granulated blast-furnace slag as a means of increasing the efficiency and durability of concrete
Authors: Иванов И.М. , Крамар Л.Я. , Мордовцева М.В.
Published: December 2023

Молотый гранулированный доменный шлак (МГДШ) применяется в качестве компонента цемента, активной минеральной добавки или наполнителя в производстве бетонов, растворов, сухих строительных смесей и других материалов. В настоящей статье приведены сведения о производстве МГДШ в ООО «Мечел-Материалы». По данным многочисленных исследований, МГДШ может обеспечить бетонам значительно бóльшую долговечность, чем у бетонов на основе портландцемента, не содержащих МГДШ. Во многих странах доменный шлак практически полностью утилизируют в производстве цементов и бетонов, но в России такой материал часто воспринимают как отход. Это в значительной степени связано с отсутствием национального стандарта на МГДШ в нашей стране, в отличие от многих других стран. В статье дана информация о разработанном и утвержденном ООО «Мечел-Материалы» стандарте организации на МГДШ, гармонизирующем требования всех европейских и российских стандартов, действие которых распространяется на МГДШ. Приведены основные результаты исследований того, как соотношение портландцемента и МГДШ влияет на основные строительно-технические свойства получаемого цемента. Данные ряда опубликованных работ показывают высокую эффективность применения МГДШ не только в рядовых, но и в высокофункциональных бетонах: быстротвердеющих, высокопрочных, водонепроницаемых, морозостойких, сульфатостойких.

Ground granulated blast-furnace slag (GGBS) is used as a component of cement, active mineral additive or filler in the production of concrete, mortar, dry building mixtures and other materials. This article provides information about the production of GGBS at OOO Mechel-Materials. According to numerous studies, GGBS can provide concrete with a significantly greater durability than Portland cement-based concretes that do not contain GGBS. In many countries, blast-furnace slag is almost completely utilized in the production of cements and concretes, but in Russia such material is often perceived as waste. This is largely due to the lack of a national standard for GGBS in this country, unlike many other countries. The article provides information on an in-house standard for GGBS, developed and approved by OOO Mechel-Materials, which harmonizes the requirements of all European and Russian standards that apply to GGBS. The main results of studies of how the ratio of Portland cement and GGBS affect the basic construction and technical properties of the resulting cement are presented. The data of a number of published works show the high efficiency of using GGBS not only in ordinary, but also in highly functional concretes: fast-hardening, high-strength, waterproof, frost-resistant, sulfate-resistant ones.
Extra fine binders (microcements) and their use in construction
Authors: Шахова Л.Д. , Харченко И.Я. , Строкова В.В. , Нецвет Д.Д. , Калатози Г.М.
Published: December 2023

В статье приводятся обзор отечественной и зарубежной технической литературы, нормативной документации, а так­же результаты исследовательских работ по технологии и свой­ствам особо тонкодисперсных вяжущих. Даны классификация цементов по дисперсности частиц, применяемая терминология, характеристики микроцементов ведущих зарубежных и отече­ственных производителей. Описаны основные технологии полу­чения микроцементов и области применения этих материалов.

The article provides an overview of domestic and foreign sources, regulatory documentation, as well as the results of research work on the technology and properties of extra fine binders. The classification of cements according to the particle size, the terms used, the characteristics of microcements from leading foreign and domestic manufacturers are given. The main technologies for obtaining microcements and the areas of application of these materials are described.
Determination of the power consumed by a centrifugal disc grinder
Authors: Богданов В.С. , Семикопенко И.А. , Беляев Д.А. , Вавилов Д.В.
Published: December 2023

В статье рассмотрена методика определения мощности центробежного дискового измельчителя, расходуемой на разрушение частиц ударом, преодоление сил трения при движении ударного элемента по слою материала и сил трения между слоями материала, преодоление сопротивления трения в подшипниках вала дисков, а также на работу дисков как вентилятора и на радиальное перемещение материала в камере помола. Полученные аналитические выражения можно применять как в учебном процессе, так и в инженерных центрах при проектировании центробежных дисковых измельчителей.

The article deals with the methodology of determining the power consumed by a centrifugal disk grinder for breaking particles by impact, overcoming friction forces when the impactor moves along the material layer and friction forces between material layers, overcoming friction resistance in the bearings of the disk shaft, as well as for the work of disks as a fan and for radial movement of material in the grinding chamber. The obtained analytical formulas can be applied both in the process of education and in engineering centers in the design of centrifugal disk grinders.
Production of white Portland cement in TOO Sastobe Technologies
Authors: Бартенев А.Н. , Таймасов Б.Т. , Даулетияров М.С. , Наумов К.С.
Published: December 2023

В ТОО «Састобе Технолоджис» для получения клинкеров белых цементов были изучены обогащенный известняк, каолины Кокшетауского и Ангренского месторождений, а также гранулированный фосфорный шлак. В результате лабораторных испытаний, а затем производственных испытаний печи размерами Ø 4 × 150 м установлено, что при обжиге двух- и трехкомпонентных сырьевых шихт при температуре 1450—1500 °C можно получить белые клинкеры 1-го и 2-го сортов с белизной до 82—85 %. В ходе производственных испытаний выпущено более 1 тыс. т белого клинкера с белизной 81—82 %.

Enriched limestone, kaolins of Kokshetau and Angren deposits as well as granulated phosphorus slag were investigated in TOO Sastobe Technologies for production of white cement clinkers. As a result of lab tests and then production tests of the kiln with dimensions ∅ 4 × 150 m it was found that with burning of two- and three-component raw material charges at a temperature of 1450-1500 °C white clinkers can be produced of the 1st and 2nd grades with whiteness up to 82-85 %. In the course of production tests more than 1 kt of white clinker with whiteness of 81 - 82 % was produced.
Dependence of vibrating mill capacity on its design and technological parameters
Authors: Богданов В.С. , Богданов Н.Э. , Анциферов С.И. , Нижегородов А.И. , Сычев Е.А.
Published: December 2023

Проведен анализ существующих конструкций помольных агрегатов, их преимуществ, недостатков, показана предпочтительная область применения. Рассмотрены различные конструктивные варианты вибрационных мельниц и принцип их работы. Описана принципиально новая конструкция вибрационной мельницы с полигармоническими колебаниями помольной камеры. Приведено уравнение регрессии для расчета производительности мельницы в зависимости от основных конструктивно-технологических параметров ее работы — частоты колебаний и коэффициента заполнения помольной камеры мелющими телами, а также от положения дебалансов относительно центра тяжести помольной камеры. Проанализированы результаты экспериментальных исследований. Установлено влияние каждого из факторов и эффектов их взаимодействия на формирование значения функции отклика — производительности мельницы. Сделаны выводы о рациональных режимах работы вибрационной мельницы, при которых достигается ее максимальная производительность.

The analysis of the existing designs of grinding mills, their advantages and disadvantages is carried out, the preferable field of application is shown. Various constructive variants of vibrating mills and the principle of their operation are considered. A fundamentally new design of vibrating mill with polyharmonic vibrations of the grinding chamber is described. The regression equation for calculating the mill productivity depending on the main design and technological parameters of its operation — the frequency of vibrations and the coefficient of filling the grinding chamber with grinding bodies, as well as on the position of eccentric weights relative to the center of gravity of the grinding chamber. The results of experimental studies are analyzed. The influence of each of the factors and the effects of their interaction on the formation of the value of the response function — the productivity of the mill has been established. Conclusions are made about rational modes of operation of the vibrating mill, at which its maximum productivity is achieved.
Cementless binders based on blast-furnace slag activated by high-calcium fly ash and Na2CO3: stability under the influence of external and internal destructive factors
Authors:  Брыков А.С. ,  Воронков М.Е.
Published: December 2023

В работе исследована стабильность бесцементных растворов, содержащих в качестве вяжущего молотые гранулированные доменные шлаки (МГДШ), активируемые высококальциевой золой-уносом в сочетании с Na2CO3, в условиях воздействия внешних и внутренних деструктивных факторов, влияющих на долговечность. Рассмотрены такие свойства, как равномерность изменения объема бесцементного вяжущего, сульфатостойкость растворов на его основе, возможность протекания щелоче-кремнеземной реакции с участием заполнителей, образование высолов. Согласно полученным результатам, у бесцементных композиций на основе МГДШ и высококальциевых зол-уноса отсутствуют деструктивные деформации расширения в условиях, стимулирующих щелоче-кремнеземные реакции при участии реакционноспособного заполнителя. При дозировке золы в пределах 10 % масс. в составе вяжущего композиции являются сульфатостойкими, однако возможность образования и развития деструктивных деформаций расширения не исключена при высоких дозировках золы (30 % масс.). От дисперсности высококальциевой золы-уноса зависят ее способность активировать гидратацию МГДШ, влияние на равномерность изменения объема вяжущего, ранняя прочность вяжущей композиции, наличие или отсутствие высолов.

The stability of cementless mortars containing ground granulated blast furnace slag as a binder activated by high-calcium fly ash in combination with Na2CO3 under the influence of external and internal destructive factors affecting durability has been investigated. Such properties as regularity of cementless binder volume change, sulfate resistance of mortars based on it, possibility of alkali-silica reaction with the participation of aggregates, formation of efflorescence are considered. According to the results obtained, cementless compositions based on ground granulated blast furnace slag and high-calcium fly ash have no destructive expansion deformations under conditions that stimulate alkali-silica reactions with the participation of reactive aggregate. At ash dosage within 10 % wt. in the binder the compositions are sulfate resistant, but the possibility of formation and development of destructive expansion is not excluded at high ash dosage (30 % wt.). The dispersivity of high-calcium fly ash determines its ability to activate hydration of ground granulated blast furnace slag, the influence on the regularity of binder volume change, the early strength of the binder composition, the presence or absence of efflorescence.