Papers by Keyword: Mineral Powder

Abstract: The paper presents the results of studies of the effect of the concentration of binder components on the properties of cement alkaline stone. Formulations of clinker-free binders of alkaline activation with the level of filling the system of 20 and 40% have been developed, the properties of the cement paste of the binding binder "aspiration dust - mineral powder - liquid glass" have been studied, the dynamics of a set of strength indicators has been studied, both for bending and compressive forces. The received results allow to estimate uniqueness of properties of a binding binder "a mineral powder - Na₂SiO₃" and to create new materials on resource saving and energy saving technology. 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.

Abstract: 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.

Abstract: Currently, construction volumes around the world are growing rapidly. Because of this fact the anthropogenic load on the natural resource potential of our planet is increasing, so special attention is paid to the development of less resource and energy-consuming technologies for building production, the development of new building composites based on the use of local secondary and substandard raw materials, the receipt of which high-temperature and expensive processing is not required. In this regard, the Grozny Scientific School of Energy and Resource Saving in the production of modern building materials has carried out the comprehensive studies to study the effectiveness of clinker-free alkaline binders as an alternative to traditional cement binders. The results presented in this article were obtained in the framework of the research on the implementation of scientific project No. 05. 607.21.0320. “Development of technology for new building composites on clinkerless alkaline binders using substandard natural and secondary raw materials” that received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020”. Unique Agreement Identifier RFMTFI60719X0320

Abstract: The alkaline clinker-free binders formulations activation development based on fine powders of aluminosilicate nature will allow to obtain the effective building composites. The paper reveals the issues related to the theoretical foundations of the cement stone structure and strength formation based on the alkaline activator. The research results, in our opinion, are undoubtedly of practical importance for the construction industry, since the proposed recipes for clinker-free cements will replace the expensive and energy-consuming Portland cement, allowing to create strong and durable concrete and reinforced concrete structures. The results presented in this article have been obtained in the framework of research on the implementation of scientific project No. 05. 607.21.0320. “Development of technology for new building composites on clinker-free alkaline binders using substandard natural and secondary raw materials” which received support from the federal target program “Research and Development in Priority Directions for the Development of the Russian Science and Technology Complex for 2014-2020”. The unique identifier for the agreement is RFMTFI60719X0320.

Abstract: The article presents the results of the study of the bitumen-retaining ability of stabilizing additives developed on the basis of cellulose-paper waste and finely dispersed fillers of various genesis. Analysis of the test results of crushed stone-mastic asphalt mixtures of the same composition showed that all additives provide the value of the runoff index of the organic binder in the mixture, which meets the requirement of the State Educational Standard No. 31015-2002. The introduction of mineral fillers into the stabilizer contributes to a decrease in the studied parameter, which is due to the additional structuring effect. For a two-component additive (without mineral filler), the studied indicator has the greatest value, exceeding the recommended limit. It is important to note that the use of mineral powder in the composition of stabilizing additives has a positive effect on the flow of the binder. Mineral powder, due to the structuring effect on bitumen and the formation of a microporous structure, reduces the run-off rate of the binder. This is due to the fact that bitumen, being in thin interlayers and small pores, falls into the region of influence of the molecules of the surface layer of the mineral part, increasing the density of granules and facilitating the granulation process of the additive. The minimum runoff of the organic binder is observed in the preparation of crushed stone-mastic asphalt-concrete mix with additives based on mechanically activated wastes of wet magnetic separation of ferruginous quartzites and is 0.07.

Abstract: The paper considers the physicochemical activation of mineral powders used in asphalt concretes. Oil storage wastes, called oil sludges, are proposed to use as a surfactant. Activation of the surface of mineral powders is accomplished during the joint grinding of powder and oil sludge in a ball mill. As a result, the surface of mineral powders acquires hydrophobic properties; their physico-mechanical characteristics are improved: the reduction of porosity, bitumen content, and of the swelling index of asphaltic substances are observed. The introduction of activated powders into the composition of asphalt concretes can significantly reduce the amount of the required bitumen in the mixture. Decrease in water saturation index is detected in asphaltic concrete with activated mineral powders unlike in the test specimen. This implies an improvement in the index of resistance to atmospheric corrosion.

Abstract: Powder-cement ratio plays a key role in asphalt mixture. Only after asphalt adsorbs the surface of mineral powder to form a thin film, asphalt produces the adsorption on aggregate, so slag asphalt is real asphalt binder. Powder-cement ratio is different, road performance is different too. Through laboratory test, analysis powder-cement ratio reflects on heat, cold, water stability and anti-reflective cracks of ATB, make a range of radio of filler to bitumen, in order to provide a reference for the design of ATB composition.

Abstract: Production cost and emissions of pollutants can be reduced through mixing industry waste, such as mineral powder and fly ash, into ready-mixed concrete. Two approaches are adopted to the experiments to research the effect of mineral powder and fly ash on the compressive strength of ready-mixed concrete: (1) fixing the amount of fly ash, while substituting equivalent amount of mineral powder for cement. (2) fixing the amount of cement, while increasing the amount of mineral powder and decreasing that of fly ash. The result of the experiment shows: when equivalent amount of mineral powder substitutes for 16% of the cement, the result is the best－the strength of concrete is deceased less than 5%. The experiment also concludes that: keeping the usage of cement constant and adding 10%-15% of mineral powder into concrete, the strength of concrete can be increased about 30%.

Abstract: Mineral powders play positive role in improving the durability of concrete subjected to alkaline and saline corrosion, where sulphate ion and chloride ion coexisted may cause serious deterioration to the reinforced concrete structures. Metakaolin, slag, fly ash and natural zeolite mixed in appropriate proportion were tested in inhibiting the deterioration. It is found that the composite powder might decreased AAR and the charge passed of concrete effectively，the while the 7d and 28d strength of cement and concrete are improved as well.

Abstract: Sulphate ion and chloride ion existed in the alkaline saline soils may cause serious problems on the durability of reinforced concrete structures, while it is found that superfine mineral powder plays positive role in the precaution of the alkaline saline corrosion. A composite cement named high performance cement (H.P.C) composed of clinker, metakaolin and fly ash powder in appropriate proportions is developed with good performance in preventing concrete from alkaline saline soil corrosion. Mortar bar test and visual examination showed that the cement could effectively control AAR and sulphate ion related expansion, and the charge passed tested according to ASTM C1202 was decreased to “negligible” level for concrete with W/B ratio of 0.3, and “very low” grade for concrete with W/B ratio of 0.45 and 0.55 when the high performance cement was used. Other properties such as low hydration heat and anti-freezing properties, as well as the uniformity of the fresh concrete (with no bleeding and segregation), made it an important material in the construction of concrete structure in alkaline saline soils.