scholarly journals POSSIBILITY OF USING VOLCANIC ROCKS IN THE CEMENT INDUSTRY

2019 ◽  
Author(s):  
В.А. Байтиев ◽  
Р.Г. Бисултанов ◽  
М.Ш. Саламанова ◽  
С-А. Ю. Муртазаев
Keyword(s):  
Strength Class ◽  
Volcanic Rocks ◽  
Cement Industry ◽  
Normal Density ◽  
High Quality ◽  
Volcanic Origin ◽  
Concrete Mixtures ◽  
Mineral Additives ◽  
Composite Cements ◽  
Active Mineral Additives

В данной статье раскрываются особенности формирования структуры цементных композиций с применением активной минеральной добавки вулканического происхождения. Полученные ре цептуры композиционных цементов позволят получать высококачественные бетоны с классом прочности от В60 до В100, снижать нормальную густоту бетонных смесей на 2530, при этом подвижность смеси остается постоянной. Кроме того, применение данной разработки позволит повышать темпы набора прочностных показателей бетона, что дает вероятность отказа от тепло вой обработки и способствует получению необходимой для распалубки прочности за промежуток времени 1824 часов. Работа выполнена в рамках исследований по реализации научного проекта 1848-200001 Высококачественные бетоны с повышенными эксплуатационными свойствами на основе местного природного и техногенного сырья , получившего поддержку Российского фонда фундаментальных исследований (РФФИ). The article reveals the features of the formation of the structure of cement compositions using active mineral additives of volcanic origin. The resulting composition of composite cements will make it possible to obtain high-quality concrete with a strength class from B60 to B100, reduce the normal density of concrete mixtures by 2530, while the mobility of the mixture remains constant. In addition, the use of this development will allow increasing the pace of a set of strength indicators of concrete, which gives the probability of refusal from heat treatment and helps to obtain the strength necessary for stripping for a period of 1824 hours.

scholarly journals Abrasive Wear Resistance of Concrete in Connection with the Use of Crushed and Mined Aggregate, Active and Non-Active Mineral Additives, and the Use of Fibers in Concrete

2020 ◽  
Vol 12 (23) ◽  
pp. 9920
Author(s):  
Lenka Bodnárová ◽  
Martin Ťažký ◽  
Lucia Ťažká ◽  
Rudolf Hela ◽  
Ondřej Pikna ◽  
...  
Keyword(s):  
Abrasion Resistance ◽  
Age Groups ◽  
High Strength ◽  
Mineralogical Composition ◽  
Concrete Mixtures ◽  
Standard Procedures ◽  
Different Types ◽  
The Impact ◽  
Mineral Additives ◽  
Active Mineral Additives

Virtually every concrete structure comes into contact with abrasive effects of flowing media or solids, which have a direct impact on the durability of concrete. An abrasive effect is most pronounced in transport or water management structures, and these structures are often designed for a significantly longer service life (usually 100 years). This research evaluates the influence of the filler component in terms of the type of aggregate and its mineralogical composition on concrete abrasion resistance. As part of the impact of the binder component, several concrete mixtures were produced using the same aggregate and maintaining the same strength class with the addition of different types of active and inert mineral additives. In other parts of the research, the effect of adding fiber reinforcement on the abrasion resistance of concrete was verified. Mutual connections and correlations in different age groups (7, 28 and 90 days) were sought for all obtained results. The abrasion resistance of the composite was monitored by using standard procedures, especially using a Böhm device. It was found that for good abrasion resistance of concrete, it is not necessary to produce concretes with high strength classes using often expensive mineral additives (microsilica) and quality aggregates, but the maturation time of the composite and its microstructure plays an important role.

scholarly journals Studying the Mineral Additives Effect on a Composition and Properties of a Composite Binding Agent

2018 ◽  
Vol 34 (4) ◽  
pp. 1945-1955 ◽  
Author(s):  
Aimenov Askar Zhambulovich ◽  
Khudyakova Tatyana Mikhailovna ◽  
Sarsenbayev Bakytzhan Kudaibergenovich ◽  
Dzhakipbekova Nagima Ormanovna ◽  
Ali Khalid Abdul Khalim Kheidar ◽  
...  
Keyword(s):  
Chemical Resistance ◽  
Environmental Safety ◽  
Cement Industry ◽  
Cement Stone ◽  
Cement Production ◽  
Essential Change ◽  
Cement Manufacture ◽  
Power Inputs ◽  
Mineral Additives ◽  
Composite Cements

A Portland cement is a basic initial component for concrete and reinforced concrete manufacture, which defines their technical-economic and operational properties. One of a perspective ways of increase in the efficiency of cement production without essential change of its technology is inclusion of various mineral additives influencing on a structure and properties of a cement stone. As power inputs make the most part of the costs necessary for cement manufacture, the cement industry is interested in decrease in fuel and electric power expenditures per 1 tonne of cement. To reach the decrease in power inputs and at the same time to raise the environmental safety of cement production the cement industry is recently focused on increase in output of composite cements. Composite cements not only promote optimization of the production in terms of ecology, but also can provide such technical advantages as lower hydration heat, higher chemical resistance and placeability.

scholarly journals Vulcânicas potássicas intemperizadas como protólitos dos filitos hematíticos da Serra do Espinhaço Meridional (Minas Gerais)

2020 ◽  
Vol 34 (2) ◽  
pp. 183-194
Author(s):  
Alexandre Chaves ◽  
Luiz Knauer
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Volcanic Rocks ◽  
Alkaline Rock ◽  
Major Elements ◽  
Volcanic Origin ◽  
Espinhaço Range ◽  
Weathering Processes ◽  
Igneous Layering ◽  
Hematitic Phyllite

The hematitic phyllite is a rock that occurs in the São João da Chapada and Sopa-Brumadinho formations of the southern Espinhaço range. Its origin is widely discussed in papers on Espinhaço, but there is no consensus on its protolith due to certain characteristics of the lithotype, such as its chemical composition and textural features. The pattern of rare earth elements strongly enriched [(La/Yb)N 6.80-17.68], with light rare earth elements [(La/Sm)N 2.54-4.83] richer than heavy ones [(Gd/Yb)N 1.28-3,32], suggests that the protolith was an alkaline volcanic rock formed during the rift that generated the Espinhaço basin. The major elements indicate that the alkaline rock met weathering processes, becoming a regolith. During the Brasiliano metamorphism, it finally became hematitic phyllite. Other characteristics of the lithotype, such as the presence of sericite-bearing rounded parts (possibly formed by alteration and deformation of leucite crystals) and the preservation of igneous layering, suggest a potassic volcanic origin for hematitic phyllite. In diagram that allows identifying altered and metamorphic volcanic rocks, the investigated samples have composition similar to a feldspathoid-rich alkali-basalt, probably a leucite tephrite, a leucitite or even a lamproite, rocks from mantle source.

scholarly journals Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

2003 ◽  
Vol 3 ◽  
pp. 308-318 ◽  
Author(s):  
Konstantin Sobolev
Keyword(s):  
Technological Development ◽  
High Volume ◽  
Cement Industry ◽  
Cement Clinker ◽  
Blended Cements ◽  
Mineral Additive ◽  
Reduction Of Energy Consumption ◽  
Special Complex ◽  
Mineral Additives ◽  
By Products

The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

scholarly journals FEATURES OF THE SELECTION OF THE RATIONAL STRUCTURE OF THE COMPOSITIONAL GIPS BINDER

2020 ◽  
pp. 45-52 ◽  
Author(s):  
N. Chernysheva ◽  
S. Shatalova ◽  
A. Evsyukova ◽  
Hans-Bertram Fisher
Keyword(s):  
Water System ◽  
Internal Stresses ◽  
Mineral Additive ◽  
The Russian Federation ◽  
Reasonable Choice ◽  
The Stability ◽  
Mineral Additives ◽  
Selection Of ◽  
Hardening System ◽  
Active Mineral Additives

the dynamically developing construction in the Russian Federation makes it necessary to expand the range of alternative types of binders and materials based on them. Such a binder is a previously developed composite gypsum binder (CGB), used for the production of materials of various functional purposes. The manufacture and use of CGB-based composites was made possible by studying the Portland cement-gypsum-water system, the stability of which is ensured by introducing an appropriate amount of active mineral additives that reduce the concentration of Ca(OH) 2 in the liquid phase of the hardening system and create the possibility of hardening under certain conditions without dangerous internal stresses. In this paper, we consider the possibility of using composite gypsum binder for fine-milled quartzitic sandstone crushing dropout and concrete scrap crushing dropout as an active mineral additive. Rational compositions of composite gypsum binder are developed and their basic properties are studied. The reasonable choice of the amount of active mineral additive allows optimizing the properties of the composite gypsum binder.

scholarly journals ВЛИЯНИЕ ЦЕМЕНТА С МИНЕРАЛЬНЫМИ ДОБАВКАМИ ИЗ МОЛОТОГО ПРИРОДНОГО ПЕСКА И ГРАНИТНОГО ОТСЕВА НА СВОЙСТВА ТЯЖЕЛОГО БЕТОНА

2019 ◽  
Author(s):  
A. Smolyakov
Keyword(s):  
Frost Resistance ◽  
Strength Class ◽  
Natural Quartz ◽  
Structural Concrete ◽  
Water Separation ◽  
Hydration Mechanism ◽  
Concrete Mixtures ◽  
Mineral Addition ◽  
Demand Changes ◽  
Increased Susceptibility

В материале статьи приведены результаты экспериментальной оценки физико-механических свойств тяжелого конструкционного бетона, полученные в сравнительном варианте: при его приготовлении на чистоклинкерном (бездобавочном) вяжущем, а также с использованием песчанистого цемента, содержащего 20 молотого природного кварцевого песка, и цемента с 20 -ой минеральной добавкой из гранитного отсева, при соблюдении правила прочих равных условий . Бетон во всех случаях готовили на вяжущем марки М500 (класс по прочности 42,5 ) исследования осуществили по стандартизированным методикам (оценка прочности, усадки, морозостойкости и др.) и нестандартизированнным при определении упруго-деформативных характеристик бетона. В результате экспериментов установлено, что бетон на песчанистом цементе характеризуется ростом деформаций усадки на 70 и повышенной предрасположенностью к трещинообразованию, что приводит к снижению прочности на сжатие до 10 , на растяжение при изгибе до 27 , к снижению водонепроницаемости и морозостойкости на 12 марки и упруго-деформативных свойств по сравнению с бетоном на цементе с добавкой гранитного отсева, а кроме этого, им не обеспечивается защитная способность по отношению к стальной арматуре. Причиной является переизмельчение его клинкерной части при совместном помоле клинкера с песком, что вызывает рост водопотребности, изменения в механизме гидратации цемента и сопровождается повышенной усадкой и трещинообразованием в цементном камне и бетоне. На этом основании сделан вывод о необходимости и рациональности замены природного песка на гранитный отсев в производстве вяжущего с минеральной добавкой белорусскими производителями цемента. С учетом изложенного экспериментально обосновано рациональное содержание добавки из гранитного отсева в цементе (в количестве до 20 его массы) и исследовано ее влияние на технологические свойства бетонных смесей (увеличивается на 2550 время сохранения формуемости, снижается водоотделение до 1015 и раствороотделение до 1020 ), а также на прочностные, упруго-деформативные и эксплуатационные свойства бетона, что позволило обосновать вывод о возможности использования полученного цемента для конструкционного бетона классов С12/15С32/40 общестроительного назначения без ограничений, включая изделия (конструкции) с преднапрягаемой арматурой.The article presents the results of an experimental evaluation of the physicomechanical properties of heavy structural concrete, obtained in a comparative version: when manufactured on a pure linker (additive-free) binder, as well as using sandy cement containing 20 ground natural quartz sand, and cement with mineral addition (in the amount of 20) from granite screening and observance of the other equal conditions rule. Concrete in all cases made on the binder brand M500 (strength class 42.5) studies were carried out according to standardized methods (strength, shrinkage, frost resistance, etc.) and non-standardized in determining the elastic-deformative characteristics of concrete. As a result of the experiments, the following was established. Concrete on sandy cement (due to overgrinding of its clinker part, which causes an increase in water demand, changes in the hydration mechanism and is accompanied by increased shrinkage) is characterized by an increase in shrinkage deformations by 70 and an increased susceptibility to cracking, which leads to a decrease in compressive strength up to 10, tensile bending up to 27, elastic-defformative properties, as well as reduction of water resistance and frost resistance - by 1 ... 2 marks in comparison with concrete on cement with the addition of granite sifting, and does not provide protective ability in relation to steel reinforcement.Taking into account the above, a rational content of an additive from granite sifting in cement in an amount of up to 20 of its mass and its influence on the technological properties of concrete mixtures (an increase of (25 ... 50) of the time to maintain moldability, reduction of water separation to (10 ... 15) and dissolution to (10 ... 20) ), as well as the strength, elastic-deformative and operational properties of concrete, which made it possible to substantiate the conclusion that the obtained cement can be used for structural concrete of classes C12 / 15 ... C32 / 40 of general construction Nogo destination without limitation, including articles (structures) with prestressing reinforcement.

Мineral Powders Dispersion Degree Effect on the Properties of the Cementing Alkaline System

2021 ◽  
Vol 1017 ◽  
pp. 31-40
Author(s):  
Said Alvi Murtazaev ◽  
Magomed Mintsaev ◽  
Madina Salamanova ◽  
Zhambui Aymenov ◽  
Arbi Alaskhanov
Keyword(s):  
Raw Materials ◽  
Cement Industry ◽  
Normal Density ◽  
Unique Identifier ◽  
Federal Target Program ◽  
Setting Times ◽  
Dispersion Degree ◽  
Scientific Project ◽  
Grinding Time ◽  
Total Specific Surface Area

This paper presents the results of studies on mineral powders dispersion degree effect on the properties of alkaline cement-water paste where powders are of natural and technogenic origin. The change dependences between the total specific surface area and the duration of grinding have been studied, and the optimal grinding time for raw materials has been revealed. The developed formulations of cementing alkaline binders, with the use of mineral powders and wastes from the cement industry, are distinguished by short setting times and high consumption of alkaline grout to obtain a cement paste of normal density, which requires further research. And the obtained influence patterns of the degree of dispersion on the properties of the "mineral powder - Na2SiO3" binder will make it possible to create strong and durable artificial building composites competing with concretes based on Portland cement. The results presented in this article were obtained within the framework of studies on the implementation of scientific project No. 05. 607.21.0320. "Development of technology for new building composites based on clinkerless cement of alkaline activation using substandard natural and secondary raw materials" supported by the Federal Target Program "Research and Development in Priority Areas of Development of the Scientific and Technological Complex of Russia for 2014-2020". The unique identifier for the agreement is RFMTFI60719X0320.

Depositional Palaeoenvironment and Models of the Eocene Lacustrine Source Rocks in the Northern South China Sea

2021 ◽  
Author(s):  
Niubin Zhao
Keyword(s):  
Organic Matter ◽  
South China Sea ◽  
South China ◽  
Deep Water ◽  
Northern South China Sea ◽  
Volcanic Rocks ◽  
Source Rocks ◽  
High Quality ◽  
Reducing Conditions ◽  
Parent Rocks

<p>      Element geochemical analysis of 94 ditch cutting samples of the shale source rock from the Wenchang Formation in the Zhuyi sub-basin and the Liushagang Formation in the Weixinan sub-basin was conducted to determine their palaeoenvironment and main controlling factors and to further establish development models. The results indicate that freshwater and a warm and humid climate were characteristics of the depositional palaeoenvironment between Wenchang and Liushagang formations. During the deposition of Wenchang Formation, the parent rocks mainly consisted of felsic volcanic rocks, the water was characterized by a high palaeoproductivity, shallow-deep water depths, and weakly reducing conditions, whereas during the deposition of Liushagang Formation, the parent rocks mainly consisted of mafic volcanic rocks,<strong> </strong>and the palaeoproductivity, palaeowater depth, and reducing conditions of the water were better than during the deposition of<strong> </strong>Wenchang Formation. The formation of high-quality source rocks in the Liushagang Formation were mainly controlled by two factors: (1) the mafic igneous rock provenance and strong weathering provided macronutrients (e.g. P, Fe) for water; (2) high palaeoproductivity provided the source of organic matter, which played a much important role than preservation condition of organic matter. For Wenchang Formation, the good preservation of organic matter which was created by the reducing environment in deep water was also necessary. Accordingly, two models were briefly summarized: a productivity and preservation model for the Wenchang Formation source rocks and a productivity model for the Liushagang Formation source rocks, both of them can develop high-quality source rocks, but the source rock quality of the former were lower than of the latter, this was mainly attributed to the difference in the nutrients and palaeoproductivity. This study provides valuable guidance for oil and gas exploration in the northern South China Sea and the study of lacustrine source rocks in other areas.</p>

IMPROVING THE QUALITY OF REPAIR OF NON-RIGID ROAD SURFACES WITH THE USE OF COLD ASPHALT CONCRETE MIXTURES

2021 ◽  
pp. 62-74
Author(s):  
А. Ф. Зубков ◽  
К. А. Андрианов ◽  
Б. Бехзоди
Keyword(s):  
Layer Thickness ◽  
Asphalt Concrete ◽  
High Quality ◽  
Repair Work ◽  
The Road ◽  
Concrete Mixtures ◽  
Factory Production ◽  
Air Temperatures ◽  
Road Surfaces

Постановка задачи. Необходимо рассмотреть технологию ремонта дорожных покрытий нежесткого типа с применением холодных асфальтобетонных смесей на битумах марок БНД, СГ и МГ. Требуется разработать математическую модель конструкции автомобильной дороги, позволяющую демонстрировать распределение температуры по толщине слоя покрытия в зависимости от конструктивных параметров дороги с учетом теплофизических свойств материалов и температурных условий её эксплуатации. Также надлежит уточнить влияние температуры смеси на предел прочности холодной смеси заводского производства. Следует провести ремонт выбоин покрытия в производственных условиях при пониженных температурах воздуха. Результаты. По результатам моделирования распределения температуры в слое покрытия доказано, что применение холодных асфальтобетонных смесей обеспечивает высокое качество ремонтных работ при температуре воздуха выше 30 °С. Получены данные о зависимости температуры нагрева основания от температуры воздуха и толщины слоя, которая обеспечивает температурные режимы холодной смеси при её уплотнении. Установлено, что предел прочности покрытия зависит от температуры. Максимальная величина предела прочности холодного асфальтобетона заводского производства обеспечивается при температуре уплотнения смеси 50-55 °С. Проведенный ремонт выбоин дорожного покрытия при пониженных температурах воздуха доказал возможность выполнения ремонтных работ с высоким качеством в данных производственных условиях. Выводы. Доказана эффективность нагрева основания выбоины перед укладкой холодной асфальтобетонной смеси при ремонте дорожных покрытий нежесткого типа со снижением температуры воздуха ниже 5 °С. Установлено влияние температуры основания покрытия на ее равномерное распределение в зависимости от температуры воздуха и толщины слоя покрытия при выполнении ремонтных работ. Полученные данные о зависимости предела прочности холодного асфальтобетона заводского производства от температуры воздуха позволяет определять параметры уплотняющих машин, обеспечивающих высокое качество ремонтных работ. Statement of the problem. It is essential to consider the technology of repair of road surfaces of non-rigid type using cold asphalt-concrete mixtures on bitumen grades BND, SG and MG. It is important to develop a mathematical model of the road structure that enables modeling the temperature distribution over the layer thickness, depending on the design parameters of the road considering the thermal and physical properties of materials and the temperature conditions of the road operation. It is also necessary to specify the effect of the mixture temperature on the tensile strength of the cold mixture of factory production. Potholes of the coating must be repaired at low air temperatures of different repair technologies in production conditions. Results. Based on the results of modeling the temperature distribution in the coating layer, it is proven that the use of cold asphalt-concrete mixtures ensures high quality of repair work at air temperatures above +30 ° C. The dependence of the heating temperature of the base on the air temperature and the layer thickness is obtained, which provides the temperature conditions of the cold mixture during compaction. It is established that the ultimate strength depends on temperature. The maximum value of the strength limit of cold asphalt concrete of factory production is provided at the compaction temperature of the mixture at +50-55⁰C. The repair of potholes of the road surface carried out in production conditions at low air temperatures proved the ability to perform repair work with high quality of work. Conclusions. It is proven that it is effective to heat the base of the pothole during repair on non-rigid road surfaces at low air temperatures before laying a cold asphalt-concrete mixture. The influence of the base temperature on its distribution over the layer thickness depending on the air temperature and the layer thickness during repair work is established. The obtained dependence of the strength limit of cold asphalt concrete of factory production on temperature allows us to determine the parameters of compacting machines that ensure high quality of repair work.

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