Wyniki wyszukiwania - BazTech

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Investigation of the properties of cast asphalt concrete mixture with the addition of fiber from the fly ash of thermal power plants

Bieliatynskyi Andrii, Yang Shilin, Pershakov Valerii, Shao Meiyu, Ta Mingyang

Materials Science Poland

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2022

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Vol. 40, No. 4

125--146

EN

The introduction of new road-building materials with advanced physical and mechanical properties is the trend in contemporary civil engineering, which aims to increase the quality of road surfaces. The use of cast asphalt concrete in the upper layers of road surfaces as a replacement for layers made of traditional fine-grained asphalt concrete will not only increase the pace of construction and repair, but also the durability and quality of the road pavement. However, this method requires operational and economic optimization. Using fiber from the fly ash of thermal power plants is one of the solutions for the design of cast asphalt concrete compositions. The aim of the work is to design the optimal composition of hot cast asphalt concrete and cold cast emulsion–mineral mixtures with the use of fiber from the fly ash of thermal power plants for the construction of thin-layer coatings of highways of all categories and values; to study their properties; and to determine the feasibility of their use as reinforcing and stabilizing additives. The method of GOST 11506, namely, "Method for determining the softening temperature of the ring and ball", with the apparatus "Lintel KiSh-20m-4" was used during the experiments. The use of standard laboratory tests made it possible to analyze the quality indicators of the materials under study and design the optimal compositions of hot cast asphalt concrete, taking into account the delamination of the mixture and the criterion of decomposition, in addition to exploring the properties of the obtained material.

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Features of the hot recycling method used to repair asphalt concrete pavements

Bieliatynskyi Andrii, Yang Shilin, Pershakov Valerii, Shao Meiyu, Ta Mingyang

Materials Science Poland

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2022

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Vol. 40, No. 2

181--195

EN

The recycling methods used in the construction and repairing of asphalt concrete pavements are being constantly improved, and the improvements mostly fall under one of the following common avenues of innovation: developing new binders based on bitumen and cement; developing new varieties of asphalt concrete and other materials having an equivalent utility and function; and developing additives that can be used in the production of new types of binders that can enhance the performance properties of the pavements. This article aims to develop the composition and determine the physical-mechanical and structural-rheological properties of asphalt concrete reclaimed by the hot recycling method and reinforced by fiber of fly ash from thermal power plants (TPP). The author of this article developed a mechanism for the interaction between fiber and bitumen in asphalt binder and acquired an optimum composition of hot granular asphalt concrete. During the research, the author evaluated the utility of fiber used as an additive in reclaimed asphalt concrete, studied its effect on the properties of hot reclaimed asphalt concrete, and examined the technological and performance properties and durability of the material obtained. The fiber of fly ash used in the hot recycling method made it possible to reduce the cost and ensure the high quality and durability of the structural layer of road pavement. Our experiments with analyses of the obtained composition indicated that employing it in the construction of the structural layer of road payment would result in superior structural integrity. Hot recycling made it possible to obtain thick bound layers characterized by the homogeneity of the material. For the first time, the author studied the effect of using fiber of fly ash from Chinese TPP in hot reclaimed asphalt concrete, and the results have proved the rationality of using this composition.

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Development of building materials based on a high content of fly ash and polycondensation products from Chinese heat and power plants

Bieliatynskyi Andrii, Yang Shilin, Pershakov Valerii, Shao Meiyu, Ta Mingyang

Materials Science Poland

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2022

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Vol. 40, No. 2

270--288

EN

The addition of fly ash from thermal power plants (TPP) and chemical additives, such as polycondensation products of acetone and formaldehyde, is an effective and economical method for increasing the strength and durability of building materials, in particular concrete. Fly ash added to the concrete and mortars at 10%–15% does not reduce their technical properties, while polycondensation products of acetone and formaldehyde plasticize and accelerate the hardening process of concrete. The study aims to substantiate the possibility of obtaining concrete on dense aggregates with a high content of fly ash through the use of polycondensation products of acetone and formaldehyde as additives, which are highly soluble in water and polyfunctional. The strength indicators were determined using standard methods. The study has shown quantitative changes in the properties of the fly ash-concrete mixture, improvement of its physical and technical characteristics, and durability of the fly ash concrete with the addition of polycondensation products of acetone and formaldehyde. In the present study, the authors determine the effect of fly ash addition on the properties of a concrete mixture, as well as the maximum possible content of fly ash that can be added to concrete to maximize certain properties required of the mixture; additionally, the same action is conducted with the addition of polycondensation products of acetone and formaldehyde concomitant with the addition of fly ash.