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1
Kroviakov, S. O., A. O. Chystiakov, А. О. Bershadskyi, and T. Shevchenko. "CONCRETES ON SECONDARY CRUSHED STONE AS A PROMISING MATERIAL FOR THE RIGID PAVEMENT BASE." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 87 (June 3, 2022): 85–91. http://dx.doi.org/10.31650/2415-377x-2022-87-85-91.
Повний текст джерелаАнотація:
In the course of research, the efficiency of application of plasticizers of different type in concretes for bases of highways on secondary crushed stone is defined. In studies of concrete compositions, the type of crushed stone, secondary or granite, changed, which allowed to compare the properties of concrete on secondary crushed stone with the properties of concrete of similar composition on granite crushed stone. In addition, the type of sand changed: Bilyaevsky or Voznesenski quarry. As modifiers used additive lignosulfonate or superplasticizer polycarboxylate type MC-PowerFlow 3200. All concrete mixtures had equal mobility P2, which was provided by variation W/C (water-cement ratio). It was found that the concrete on the secondary crushed stone is characterized by a significantly higher W/C mixture due to greater porosity and damage to the surface of the coarse aggregate. The average density of concrete on secondary crushed stone is 4.2-4.4% lower compared to the average density of concrete on granite crushed stone. The average density of concrete on the larger sand of the Voznesenski quarry is 25-30 kg/m3 higher than the average density of concrete on similar gravel and finer sand of the Bilyaevsky quarry. In composites based on CEM III/A and using lingosulfonate additives, the compressive strength of concrete on secondary crushed stone is 12-13% lower compared to the strength of concrete on granite crushed stone and similar sand. However, when using the more efficient MC-PowerFlow 3200 additive, the difference in concrete strength on secondary and granite crushed stone is only 5.4% (29.8 MPa and 31.4 MPa, respectively). The strength of concrete on the sand of the Voznesenski quarry is 4-6% higher than the strength of concrete on similar gravel and finer sand of the Bilyaevsky quarry. It was found that the tensile strength when bending concrete on secondary and granite gravel when using the additive MC-PowerFlow 3200 was 2.75 MPa and 2.87 MPa, respectively, which differs by only 4%. Thus, the tensile strength of bending concrete on secondary crushed stone was almost no different from the tensile strength of similar concrete on granite crushed stone. This can be explained by the peculiarities of the aggregate with a porous surface, which is characterized by high adhesion to the cement-sand matrix. In general, the strength of concrete on secondary crushed stone using slag-containing cements allows them to be used effectively for road bases.
2
Khafizova, E. N., I. F. Panchenko, and D. A. Panchenko. "Use of rock crushing technological wastes for cement concrete compositions." Russian Automobile and Highway Industry Journal 18, no. 6 (January 17, 2022): 790–99. http://dx.doi.org/10.26518/2071-7296-2021-18-6-790-799.
Повний текст джерелаАнотація:
Introduction. the article deals with the issues of the use of technological waste generated during rocks crushing.Materials and Methods. In the research the rock crushing screenings from the Rezhevsky crushed rock plant and dolomite screenings from the Satkinsky crushed rock plant were used. The data on the physical-mechanical properties of crushing waste is presented, as well as a study of dusty rock cuttings made with a Fritsch Analysette 22 laser particle size analyser. The structure of concrete was analyzed by JEOL JSM-6510 electron microscope.Results. The studying results of heavy weight cement concretes of classes B22.5 - B40 with crushed stone are presented in the article. To control the properties of concrete an MC-PowerFlow 3100 hyperplasticizer additive and an air-entraining additive Centrament Air 202 were used. The phase composition of the contact zone between the cement stone and the aggregate - granite screening has been investigated.Conclusion. compositions of heavy concrete have been developed with the use of crushed stone screenings and chemical additives to regulate concrete properties. A pilot batch of reinforced concrete products was produced at the Rotor reinforced concrete plant in Vinzili, Tyumen Region.
3
Yastremsky, D. A., T. N. Abaydullina, and A. I. Kudyakov. "CRUSHED-STONE AND MASTIC ASPHALT WITH CELLULOSE CONTAINING ADDITIVE." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture 21, no. 5 (October 29, 2019): 180–91. http://dx.doi.org/10.31675/1607-1859-2019-21-5-180-191.
Повний текст джерелаАнотація:
High-quality and durable asphalt pavement ensures safe and comfortable traffic, optimal logistics costs, territory attractiveness to construction investments, and industrial development. With constantly increasing loads on road pavements, it is necessary to improve the asphalt quality by introducing additives into the mixture, design methodology, scientific justification for the selection and preparation of raw materials. The paper proposes the development algorithm of crushed-stone and mastic asphalt modified by the new stabilizing additive, which consists of 90 % of cellulose fiber from waste paper, 5 % rubber powder, and 5 % bitumen. The optimal particle size distribution of the mineral component in the crushed-stone and mastic asphalt is considered to be 73% of crushed stone with fractions of 15–20, 10–15 and 5–10 mm, 16 % of dolomite sand from crushing screenings, 11 % of mineral powder, 0.4 % of stabilizing additive and 5.5 % of bitumen. The compressive strength of the developed composition is 2.3 times higher than that meeting the requirements of GOST 31015–2002 for the climatic zone II. The research results are confirmed by pilot-industrial tests in constructing the road pavement in Tyumen.
4
Efimov, Vladimir, Denis Pogodin, and Myhammet Fakhratov. "Technological processes of reusing crushed concrete in the demolition of buildings in construction." E3S Web of Conferences 110 (2019): 01038. http://dx.doi.org/10.1051/e3sconf/201911001038.
Повний текст джерелаАнотація:
The paper is dedicated to waste processing management in waste processing technology. Processing of scrap concrete waste, similar in composition and condition to traditional raw materials, is economically and ecologically feasible. Secondary crushed stone obtained by crushing scrap of reinforced concrete panels in demolished five-storey apartment blocks of the first phase was studied. It is shown that concrete with scrap concrete waste shows strength properties similar to primary concrete and helps organize waste-free production. The methods of recycled waste usage, especially usage of secondary crushed stone made of crushed concrete scrap, are becoming ever more relevant with every passing year. Imported concrete aggregate volumes can be reduced by 15-30% due to usage of secondary crushed stone. Consideration of industrial waste problem and methods of solving this problem by using waste in construction industry, including secondary crushed stone made of crushed concrete scrap, is made. Annually, about 11.5 million tons of construction waste is generated in Moscow. The use of industrial waste similar in terms of composition and condition of traditional raw materials unquestionable from economic and environmental point of view. This study showed that concrete using fine granulated blast furnace slag as cement additives has higher initial strength characteristics.
5
Trautvain, A. I., V. V. Yadykina, and S. S. Tobolenko. "Study of the Influence of Thin-Dispersed Powders on the Structuring Ability of Stabilizing Additives." Materials Science Forum 974 (December 2019): 37–42. http://dx.doi.org/10.4028/www.scientific.net/msf.974.37.
Повний текст джерелаАнотація:
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.
6
Mudrychenko, Anatolii, Ivan Balashov, and Sergey Illyasch. "USE OF ACRYLIC COPOLYMER ADDITIVE SOIL STABILIZATION PLUS FOR PREPARATION OF MIXTURES MADE BY COLD RESYCLING TECHNOLOGY AND CRUSHED STONE-SAND MIXTURES IN PAVEMENT FOUNDATION LAYERS." Dorogi i mosti 2021, no. 24 (October 1, 2021): 48–59. http://dx.doi.org/10.36100/dorogimosti2021.24.048.
Повний текст джерелаАнотація:
ntroduction. Rehabilitation of public roads network requires a comprehensive recovery with strengthening of the bearing capacity of the pavement foundation. Rehabilitation of the foundation bearing capacity performed by arranging layers of road material made by cold recycling technology (hereinafter — CRRM) in accordance with [4] or by arranging a layer of crushed stone — sand mixture reinforced with cement or complex binder (hereinafter — CSSM 20) according to [13]. Purpose. The purpose of the work is to study the feasibility of using acrylic additives for the preparation of mixtures made by cold recycling technology and crushed stone-sand mixtures treated with cement in the layers of pavement foundation. Materials and methods. Experimental comparative tests of CRRM and CSSM 20 with different content of complex binder were performed. Results. Feasibility of acrylic additives use has been established (hereinafter — the additive) for the preparation of CRRM and CSSM 20 in the pavement foundation layers. Recommendations on technological parameters of preparation, transportation, laying and compaction of mentioned mixtures are given. Conclusions. Performed researches have shown that according to physical and mechanical indicators CRRM and CSSM20 meet the requirements of the current normative documents of Ukraine. The advantages of use are noted.
7
Yastremskiy, D. "RESEARCH OF BITUMINOUS BINDER WITH STABILIZING ADDITIVES BY INFRARED SPECTROSCOPY AND X-RAY SPECTRAL ANALYSIS." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 5, no. 11 (December 4, 2020): 24–31. http://dx.doi.org/10.34031/2071-7318-2020-5-11-24-31.
Повний текст джерелаАнотація:
Increasing the volume of crushed stone-mastic asphalt concrete used in the upper layers of road surfaces requires the development of effective stabilizing additives that ensure the uniformity of the asphalt mixture during short-term storage and transportation, as well as improving the properties of asphalt concrete. This additives include a complex stabilizing additive of the following composition: 90 % cellulose fibers from waste paper, 5 % rubber powder, 5 % viscous petroleum bitumen of the BND 90/130 brand. This article presents the results of a study of bitumen with the addition of "Viatop 66" and a complex cellulose-containing stabilizing additive (CSD). Using Fourier-transform spectroscopy, graphical data are obtained. as a result of their analysis, it is found that the interaction of stabilizing additives for crushed-mastic asphalt concrete with bitumen leads to the appearance of additional absorption bands characteristic of aromatic compounds (CH, benzene ring), sulfur-containing functional groups S=O st, R-SO-R, R-SO-OH, R-SO2-R, C=S st, as well as for C-O-H groups. X-ray spectral analysis confirmed the presence of additional sulfur-containing spectra in the composition of stabilizing additives. It is found that depending on the chemical composition of the stabilizing additives, the physical and mechanical characteristics of the bituminous binder and the resulting asphalt concrete change.
8
Fomina, Natalya, Irina Pavlova, and Maria Kochergina. "Industrial Waste as Components of Building Materials." E3S Web of Conferences 222 (2020): 04002. http://dx.doi.org/10.1051/e3sconf/202022204002.
Повний текст джерелаАнотація:
The possibilities of using large-tonnage waste from the Saratov region in the production of building materials are analysed. Waste was investigated: phosphogypsum - waste from the production of mineral fertilizers; steel-making slag, limestone crushing waste, construction waste (crushed concrete). The extraction of strontium and rare-earth metals from phosphogypsum is substantiated, followed by its processing into products that solidify according to the non-hydration principle, or use in the compositions of expanding cements. The development of geopolymer binders of alkaline activation based on steel-making slags is proposed. The introduction of low water demand carbonate cements into construction practice has been substantiated. Limestone crushing waste can be used as a carbonate mineral additive. The processing of crushed concrete waste into crushed stone, coarse sands and finely dispersed additives into cement concretes is considered. Technologies for processing large-tonnage waste in the production of building materials are environmentally sound and economically justified.
9
Shekhovtsova, S. Yu. "Features of the Formation of Properties of Stone-Mastic Asphalt Concrete Based on a Warm Polymer Modified Binder." Materials Science Forum 992 (May 2020): 200–205. http://dx.doi.org/10.4028/www.scientific.net/msf.992.200.
Повний текст джерелаАнотація:
Stone mastic asphalt concrete is one of the main types of asphalt concrete used for the construction of road surfaces. The quality, reliability and longevity of which depends on road safety of vehicles. To reduce the intensity of aging processes occurring at the stage of production and laying of asphalt concrete, "green" technologies are used, based on the use of physical and chemical processes that reduce the viscosity of bitumen to produce warm asphalt mixtures. This paper discusses the features of the formation of properties of crushed stone-mastic asphalt mixes SMA-15 based on polymer bitumen modified, compacted at lower temperatures, relative to traditional asphalt concrete. The influence of chemical additives of domestic and foreign production of DAD-TA and Cecabase RT 945 on the properties of modified binder and asphalt concrete was studied. It was established that they have a positive plasticizing effect on the modified bitumen binder in crushed stone-mastic asphalt concrete without a decrease in heat resistance and adhesive strength, which made it possible to compact asphalt concrete samples at low temperatures (up to 130°C) without negatively affecting the strength and deforming properties of asphalt concrete.
10
Shepelev, I. I., E. I. Zhukov, E. N. Eskova, E. V. Kiryushin, and O. V. Рilyaeva. "Promising Ways to Recycle and Use Waste from Gas Purification Facilities of Alumina Production." Ecology and Industry of Russia 26, no. 6 (June 3, 2022): 4–9. http://dx.doi.org/10.18412/1816-0395-2022-6-4-9.
Повний текст джерелаАнотація:
For the disposal of dust from gas-cleaning facilities of sintering furnaces, in addition to a closed dust circulation scheme, a partial removal of it from electric filters for subsequent use in road construction is proposed. It is shown that dust collected from 4–5 fields of electrofilters containing chlorides and sulfates should be used as additives in a nepheline-crushed stone mixture, which will allow obtaining the required high frost resistance indicators of road mix samples.
11
Zhdaniuk, Valeriy, Oleksandr Volovyk, Dmytro Kostin, and Sergey Lisovin. "An investigation of the effect of thermoplastic additives in asphalt concrete mixtures on the properties of different types of asphalt concrete." Eastern-European Journal of Enterprise Technologies 2, no. 6 (110) (April 12, 2021): 61–70. http://dx.doi.org/10.15587/1729-4061.2021.227806.
Повний текст джерелаАнотація:
The effect of modification of asphalt concrete mixtures of different grain sizes with “Ric-Polycell” (Ukraine) and “Duroflex®-SMA” thermoplastic polymers (Germany), which were added directly to the asphalt mixer during their preparation, on the properties of asphalt concrete was studied. It is confirmed that it is more expedient to use stone mastic asphalt concretes with a larger size of mineral crushed stone grains on high-traffic roads, as they are more rutting-resistant compared to asphalt concretes with smaller size and content of crushed stone grains. The effect of the temperature of preparation and thermostating of asphalt concrete mixtures modified with the investigated thermoplastics on the compressive strength of asphalt concrete at a temperature of 50 °С, which were made of the studied mixtures, was investigated. It was found that the maximum possible temperatures of preparation and thermostating of asphalt concrete mixes provide a more complete modification. The effect of the content of thermoplastic polymers in the composition of asphalt concrete mixtures on the properties and rutting resistance of fine-grained asphalt concrete, as well as stone mastic asphalt concrete, was studied. It was found that adding the “Ric-Polycell” polymer in the amount of 1.5 % and 3 % by weight of bitumen in the composition of the studied asphalt mixtures in the asphalt mixer during their preparation increases the rutting resistance of asphalt concrete under the studied conditions by 2.52–3.86 times. Modification of asphalt concrete mixtures with the “Duroflex®-SMA” additive in the amount of 0.3 % and 0.6 % by weight of the aggregate by a similar technology also allows increasing the rutting resistance of the obtained asphalt concrete by 1.86–3.16 times. Using these modifiers in the future will have a positive effect on the service life of the entire pavement structure
12
Shlyakhova, Elena A., Inna O. Egorochkina, Irina A. Serebryanaya, and A. A. Matrosov. "Methods of Investigating and Quality Assessing Structure of Concretes with Combined Aggregates." Materials Science Forum 931 (September 2018): 618–23. http://dx.doi.org/10.4028/www.scientific.net/msf.931.618.
Повний текст джерелаАнотація:
Concrete on Portland cement and cement modified with expanding additives were studied. The authors present the results of study of the modified concrete with combined aggregate. Combined aggregate is a composition of natural granite and limestone crushed stone mixed with crushed concrete. Structure and properties of concrete with combined aggregate is insufficiently studied, which limits their use in civil engineering Recycling of building materials allows to expand the raw material base, to solve the problems of resource conservation and environmental protection. The regularities and causes of changes (reduction) indicators of the quality of concrete with combined aggregate. Studying of properties and laws of formation of structure of concrete at the same time is a method of control of their production. The valuation of properties of concrete with combined aggregates will allow to use them along with traditional concrete.
13
OHASHI, Masaharu, Hiroshi TAMURA, and Yasuo TANIGAWA. "STUDY ON THE UTILIZATION OF CRUSHED STONE FINES AS ADDITIVES FOR CONCRETE : Study on test methods of grading, specific surface, and amount of clay ratio of crushed stone fines." Journal of Structural and Construction Engineering (Transactions of AIJ) 65, no. 532 (2000): 7–11. http://dx.doi.org/10.3130/aijs.65.7_5.
Повний текст джерела
14
Navolokina, S., V. Yadykina, and Anatoliy Gridchin. "CRAWLER-MASTIC ASPHALT CONCRETE WITH THE USE OF BITUMEN MODIFIED BY SEVILEEN." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 6, no. 8 (August 13, 2021): 8–16. http://dx.doi.org/10.34031/2071-7318-2021-6-8-8-16.
Повний текст джерелаАнотація:
Heavy traffic reduces the strength characteristics of asphalt concrete, causes peeling on the pavement. Crushed stone-mastic asphalt concrete is designed for the device of the upper layers of the coating on roads with high traffic intensity. The use of polymerasfalt concrete on a modified binder can lead to an improvement in the physical and mechanical characteristics of asphalt concrete and increase its re-sistance to climatic influences. The main aspects of improving the quality of crushed stone-mastic as-phalt concrete (SMA) due to the use of a binder modified with sevilen (SEVA) are discussed. The effect of bitumen containing sevilen with 22 and 29 % vinyl acetate groups on the properties of crushed stone-mastic asphalt concrete has been investigated. Analysis of the results showes that the use of modified binders has a positive effect on the entire complex of physical and mechanical parameters of polymer asphalt concrete. An increase in the strength of the samples at 20 and 50 °C, a decrease in this indicator at 0 °C is established. The indicators of water and heat resistance, shear resistance and crack resistance are also improved, which should have a positive effect on the durability of the road surface. Rational concentrations of polymer additives and the amount of vinyl acetate groups in its composition have been established. The adhesion of the binder to the mineral part of the asphalt con-crete mixture is estimated. The index of sensitivity to temperature differences of asphalt concrete sam-ples is considered due to the fact that asphalt concrete is a material that reacts to temperature fluctua-tions in the external environment. The analysis of the results of the tests carried out demonstrates that the use of modified binders has a positive effect on the entire complex of physical and mechanical pa-rameters of polymer asphalt concrete.
15
Bazhenov, Yu M., S.-A. Yu Murtazaev, D. K.-S. Bataev, A. H. Alaskhanov, T. S. A. Murtazaeva, and M. S. Saydumov. "High-strength concretes based on anthropogenic raw materials for earthquake resistant high-rise construction." Engineering Solid Mechanics 9, no. 3 (2021): 335–46. http://dx.doi.org/10.5267/j.esm.2021.1.004.
Повний текст джерелаАнотація:
This work is devoted to development of optimum recipes of high-strength concretes based on filled binders with fine-milled anthropogenic mineral filler intended for earthquake resistant high-rise monolithic construction. The optimum recipes of concretes in this work have been developed on the basis of computations and experimental designing of cast concrete mixes with chemical additives and anthropogenic mineral fillers, as well as destructive inspection methods as the most precise for analysis of physicomechanical and deformation properties of concrete. The following raw materials have been used for production of high-strength concretes: natural quartz sands with the fineness modulus F.M. = 1.7-1.8; crushed limestone with the particles sizes of 5-20 mm; water reducing chemical additives and hardening retarder to control specifications of concrete mixes; plain Portland cement, grade PTs 500 D0; anthropogenic mineral additives (fillers) in the form of crushed concrete and ceramic bricks. Optimum recipes of monolithic concretes have been designed using anthropogenic raw materials including normal concrete grades with compressive strength of M30-M40 and high-strength concrete grades of M50-M80, characterized by high homogeneity of cement stone with significantly finer pores and lower shrinkage. Herewith, it has been established that fine-milled anthropogenic mineral filler in the form of crushed concrete and ceramic bricks at the ratio of 70:30, respectively, efficiently influences specifications of concrete mixes on their basis significantly increasing resistance of the mix against sedimentation and water gain. It has been established that the developed high-strength concretes based on filled binders with fine-milled anthropogenic mineral filler are characterized by high freeze–thaw resistance (from F400 to F600) and water tightness (W14 and higher), which is a solid base providing high lifecycle of such concretes.
16
Polyakov, Igor V., Mikhail V. Barannikov, and Ekaterina A. Stepanova. "ADDITIVES FOR HEAVY CONCRETE BASED ON INDUSTRIAL WASTE FROM CHEMICAL INDUSTRIES." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 4 (April 12, 2021): 104–9. http://dx.doi.org/10.6060/ivkkt.20216404.6330.
Повний текст джерелаАнотація:
The effect of a complex additive containing superplasticizer C-3 on the properties of heavy concrete has been investigated. The efficiency of the plasticizing action of the specified additive at the stage of preparation of the concrete mixture and subsequent molding of concrete products has been revealed. It is proved that at the stage of concrete hardening, the investigated additive promotes to the formation of a more homogeneous colloidal-crystalline structure and the formation of dense crystalline hydrate complexes of cement stone by the time of completion of concrete hardening. The objects of investigation were samples of grade B22.5 concrete without additives; containing a monoadditive - superplasticizer S-3; containing the complex additive. When designing the composition of additives for heavy concrete, we proceeded from the fundamental provisions of construction science that the complexity of the action of additives lies in the optimal combination of two main opposite processes in time and volume of the concrete matrix. The use of the caprolactam oligomer synthesized in the course of this investigation makes it possible to solve the problem of involving concentrated wastes of caprolactam production in the production turnover. The obtained caprolactam oligomers can be used in construction as plasticizers of concrete mixtures, as inhibitors of corrosion of steel reinforcement in the production of reinforced concrete products. Water-soluble oligomers of caprolactam, which reduce the time of dissolution of the superplasticizer C-3 and the dispersion of low-temperature catalyst in the volume of the concrete mixture being mixed, were synthesized. It was found that in the presence of the oligomer caprolactam in an amount of 10 to 20% of the mass. the dissolution rate of S-3 superplasticizer in water at a temperature of 20-21 °C increases by 2.0-2.2 times. This contributes to a better mixing of the components of the concrete mixture, primarily to improve the dispersion of the complex additive in the volume of the concrete mixture. The caprolactam oligomer used in this research work is an effective water-soluble wetting agent for the surface of particles of cement, sand, and crushed stone, which is very important for activating hydration and sorption processes during mixing of a concrete mixture. The increased wetting properties of the caprolactam oligomer are characterized by a wetting angle of 19.6 °.
17
Lishtvan, Ivan I., Boris V. Kurzo, Oleg M. Gaidukevich, and Alexandr I. Sorokin. "PROSPECTS FOR LOCAL MINERAL AND RAW MATERIALS USE FOR THE DEVELOPMENT OF THE SOUTHWESTERN REGION OF GOMEL REGION." Nature Management, no. 2 (December 28, 2020): 77–87. http://dx.doi.org/10.47612/2079-3928-2020-2-77-87.
Повний текст джерелаАнотація:
The results of the study of the resource potential of Lelchitsky and adjacent regions are presented. It is shown that the raw materials for the production of crushed stone and natural stone in the amount of 1 million m3 is actively extracted in the region with the prospect of volume increasing up to 10 million m3. In addition, peat and sapropel
are mined for the production of organic fertilizers, feed additives and drilling fluids. Brown coal and bentonite clay deposits
are promising for mining. Peat, sapropel and brown coal should be considered to be raw materials for complex deep processing with the release of more products and materials with high added value.
The obtained results allow to conclude that the development of Lelchitsky region and the economic feasibility of building Polesie section of the railway is possible only through integrated development and the most complete use of the entire resource base of the region.
18
Li, Xinsheng, Zhaoxing Xie, Wenzhong Fan, Lili Wang, and Junan Shen. "Selecting warm mix asphalt additives by the properties of warm mix asphalt mixtures - China experience." BALTIC JOURNAL OF ROAD AND BRIDGE ENGINEERING 10, no. 1 (March 10, 2015): 79–88. http://dx.doi.org/10.3846/bjrbe.2015.10.
Повний текст джерелаАнотація:
The objective of this research was to select the most effective warm asphalt additives for mix practice based on a series of laboratory testing programs such as density, Marshall stability, freeze-thaw splitting strength, dynamic stability, and bending beam strain. The experimental design of warm mix asphalt included the use of three commonlyused additives, two typical aggregate gradations, one crushed aggregate, and one modified asphalt. Results showed that: (1) the bulk specific gravity and air voids of all the mix specimens were similar to those of controls; (2) the Marshall stability and flow values of the warm stone mastic asphalt were 6.8%–26.6% and 3.5%–10.3%% higher than those of controls, respectively, and those of the warm asphalt concrete were 6.1%–15.6% and 6.5%–9.7% higher than those of controls, respectively; (3) the indirect tensile strength of two types of mixtures was 1.7%–14.4% lower than that of controls, and the average tensile strength ratio of the warm stone mastic asphalt and asphalt concrete was 4.3% and 1.3% higher than that of controls, respectively; (4) the dynamic stability of warm mix specimens was 10.8%–16.6% lower than that of the controls; (5) the average bending failure strain of warm stone mastic asphalt was 7.6% higher than that of the controls, and that of warm asphalt concrete was 12.8% lower than that of the controls; (6) Overall, warm asphalt mixtures with Sasobit and Rediset had relatively best performances required in Southeast China, where rutting and stripping are the main failures of asphalt pavements.
19
Vinogradova, L. A., and Y. P. Rusakova. "Infrared spectr of SP–2VU superplastifying agent and a cement mortar with additive." Proceedings of the Voronezh State University of Engineering Technologies 81, no. 1 (July 18, 2019): 289–93. http://dx.doi.org/10.20914/2310-1202-2019-1-289-293.
Повний текст джерелаАнотація:
To improve the concrete properties, various technological methods are used, the most accessible ones being the introduction of chemical additives into the concrete mixture, which can significantly reduce the costs level per unit of production; these additives improve concrete quality and effectiveness and reinforced concrete structures as well as increase their service life and buildings and structures in whole. This paper presents the results of studying the effect of introducing a superplasticizer with stabilizing effect of Polyplast SP – 2VU LLC Polyplast Novomoskovsk into concrete by analyzing the IR spectra of the additive in pure form and as part of hardened cement mortar (0.1–0.9%). Portland cement CEM I 42.5 B of Mordovcement OJSC was used as a binder; the aggregates were enriched with quartz sand from the Khromtsovsky deposit with a size of 2.4 and granite crushed stone of the Orsk deposit of 5–20 mm with water absorption of 0.2% . In the course of the work, the chemical composition of the additive SP2-VU itself and the hardened modified concrete composition were analyzed. Thus, the introduction of a modifier into a concrete composition leads to the change in its structure and strength characteristics. It was established with the help of IR spectra, that when the content of the additive in the cement mortar is 0.5%, a more ordered and stable hardened structure is formed. The reliability of the data obtained is confirmed by the identification of the main peaks. Due to the modification of concrete (at 0.3-0.5% in the concrete mix regulator concentration), the increase in the strength of the samples is more than 40%.
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Velichko, Evgeny Georgievich, and Nikolai Ivanovich Vatin. "Reactive Powder Concrete Microstructure and Particle Packing." Materials 15, no. 6 (March 17, 2022): 2220. http://dx.doi.org/10.3390/ma15062220.
Повний текст джерелаАнотація:
The subject of this study is the dispersed composition of multicomponent cement systems. This study aims to reduce interparticle voids, increasing the strength and concentration of the solid phase. The investigated concrete mixture contained two fine aggregate fractions, granite-gabbro crushed stone of 5–10 mm fraction, Portland cement of CEM I 42.5N class, finely dispersed granular blast furnace slag, microsilica, highly dispersed cement fraction, superplasticizer Glenium 430, and high-valence hardening accelerator. A laser analyzer determined the shape and size of dispersed particles of the components. The structure of the cement stone was studied by scanning microscopy, thermographic, and X-ray phase analysis methods. The strength of concrete with an optimized dispersed composition at the age of 2 days was 52, 63, and 74 MPa, while that at the age of 28 days was 128, 137, and 163 MPa. For this concrete, the consumption of multicomponent cement was 650, 700, and 750 kg/m3, respectively. The high efficiency of the application of bimodal clinker component and granulated blast-furnace slag is shown. It is established that the optimal content of nanoscale additives, including microsilica, should be insignificant and determined experimentally.
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Yadykina, V. V., S. N. Navolokina, and A. M. Gridchin. "Water- and frost-resistance of crushed stone mastic asphalt concrete prepared on sevilen-modified bitumen." Russian Automobile and Highway Industry Journal 19, no. 1 (March 18, 2022): 102–13. http://dx.doi.org/10.26518/2071-7296-2022-19-1-102-113.
Повний текст джерелаАнотація:
Introduction. Currently, increasing the durability of road asphalt concrete pavements is one of the urgent issues, the solution of which provides a significant economic effect achieved by increasing the turnaround time, as well as the overall service life of highways. Asphalt concrete pavements with prolonged wetting due to weakening of structural bonds can be destroyed due to crumbling of mineral grains, which leads to increased wear of the pavement and the formation of potholes. Water penetrates into micro defects in the structure of asphalt concrete, leading to a decrease in the strength of the material. As a result, the corrosion resistance of asphalt concrete is reduced. To improve the quality of the binder and the durability of the asphalt concrete pavement, in particular from crushed stone-mastic asphalt concrete (SMA), various modifying additives, including polymer ones, are used. In this regard, a promising direction is the use of polymers containing active groups, which are able to provide an increase in adhesion to mineral materials, including those from acid rocks, and, consequently, water resistance. One of these is the ethylene vinyl acetate copolymer (EVAC).Materials and methods. In order to study the effect of sevilen on the water and frost resistance of asphalt concrete mixtures, crushed stone-mastic asphalt concrete mixtures were prepared based on bitumen modified with БНД 70/100 sevilen made in the Moscow Oil Refinery Plant was used as the initial bitumen in the preparation of modified binders. Tests of crushed stone-mastic asphalt concrete mixtures were carried out for the indicator of the content of air voids in accordance with GOST R 58406.8.2019, the coefficient of water resistance in accordance with GOST R 58401.18-2019 and frost resistance in accordance with GOST 12801-98.Results. It has been established that the content of air voids in asphalt concrete samples significantly decreases with an increase in the concentration of sevilene, which will further contribute to a higher frost resistance of the road surface. It is shown that the use of sevilen with 22% vinyl acetate makes it possible to increase the coefficient of water resistance of asphalt concrete mixtures due to the presence of polar molecules in the composition of ethylene vinyl acetate, actively interacting with the mineral components of the asphalt concrete mixture. The use of sevilen improves the frost resistance of asphalt concrete samples. So, the smallest decrease in strength in tests for frost resistance was shown by samples with 5% sevilene. It was found that polymer asphalt concrete based on binder with sevilene containing 22% vinyl acetate, which corresponds to the maximum basicity of the polymer, has the highest resistance to humidity and temperature effects of the environment.
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CMSE, C., Huaquan YANG, Zhen LI, Meijuan RAO, and Xiaomei SHAO. "Study on Influence of Aggregate Combination and Inhibition Material ofAlkali-silica Reaction in Fully-Graded Concrete." Materials Science 26, no. 3 (February 27, 2020): 363–72. http://dx.doi.org/10.5755/j01.ms.26.3.19451.
Повний текст джерелаАнотація:
The influences of aggregate combination and inhibitor additives on the Alkali-silica Reaction (ASR) were studied in this research. A long-term alkali activity simulation of fully-graded concrete also was carried out. The results showed that replacement of artificial sandstone sand with artificial marble sand reduced the alkali activity expansion rate of the sandstone aggregate and effectively improved the inhibition effect of the aggregate when mixed with 35 % fly ash. Activated silica in the fly ash was crushed into particles and was mixed into each part of the concrete system. It transformed the limited parts into unlimited active centers. As a result, each center participated in the reaction and consumed the alkali. Inhibition of the ASR was effective when the fly-ash content of the ASR-1 was 15 %, while in the ASR-2, the fly-ash did not have a significant inhibition effect. During a long-term simulation, the expansion rate of theconcrete specimens after standard curing at 20 °C was higher than was the expansion rate after outdoor natural curing. The expansion rate of full sandstone concrete specimens was higher than was that of sandstone specimens that contained marble stone.
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Maksimova, About the author: Irina N. "Influence of chemical additive and reduced initial temperature of structure formation and hardening on parameters of structural strength of cement composites." Vestnik MGSU, no. 4 (April 2019): 442–49. http://dx.doi.org/10.22227/1997-0935.2019.4.442-449.
Повний текст джерелаАнотація:
Introduction. Comparative experimental studies have been conducted to study the regularities of the combined effect of low temperatures and concentration of accelerating antifreeze additives on the processes of early and late structure formation and hardening of cement composites. At the same time, the power and energy characteristics of crack resistance are evaluated from the standpoint of structural fracture mechanics for structural materials. Materials and methods. The following components are used to fabricate experimental samples: Portland cement with the activity of 41.8 MPa, limestone crushed stone of the fraction of 5 to 10 mm, Sura river sand with the fineness modulus of 1.57, an accelerating antifreeze additive based on a mixture of three Akrikhin plant salt wastes. Water-cement ratio in all compositions is 0.53. Concentration of the additive in the compared sample series Nos. 1 to 5 is respectively 0, 0.75 %, 1.5 %, 3.0% and 6.0 % by weight of cement. Type I prism samples with an artificial crack obtained in the process of sample molding are tested for three-point bending with non-equilibrium mechanical tests according to GOST 29167-91 which involves the use of an acoustic emission method to study the real-time fracture process of compared series samples. Results. Quality parameters of the structural strength are obtained for the compared series cement composites at the ages of 40 days and 575 days. The parameters reflect the processes of the early and late stage of structure formation and hardening after the initial 28-day environmental exposure with the temperature of +2 °C. Conclusions. Results of the research indicate that not only increase of magnitude of the long-term axial compression and tension-in-bending strength, but also increase of the mechanical-acoustic crack resistance criteria occurs for the modified and unmodified structures of cement composites in the considered time interval. This is a clear consequence of the positive effect of concentration of the accelerating antifreeze additives on the mechanical behavior of the samples from the standpoint of structural mechanics of materials destruction, which plays an important role in the design of the structural strength of dispersed cement heterogeneous systems.
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Grabosky, Jason, and Nina Bassuk. "190 Growth Response of Four Tree Species to Fertilization and Humate Additives to CU Soil." HortScience 35, no. 3 (June 2000): 423C—423. http://dx.doi.org/10.21273/hortsci.35.3.423c.
Повний текст джерелаАнотація:
CU soil is a material primarily composed of clay loam soil and crushed stone designed for use under pavement to promote street tree root growth in a durable pavement section, such as sidewalks or parking lots. One concern is the low total soil fraction from which tree roots can meet nutritive demands. At issue is the long-term nutrient management of street trees once the root zone has been rendered inaccessible due to the pavement wearing surface, although in 3-year field tests, there were no differences found between a CU soil material and an agricultural field control. CU soil treatments were produced in a factorial design with a patent applied for processed humate additive, and a nursery production fertilization treatment. Bare-root seedlings of Salix nigra Marsh, Platanus × acerifolia Willd., Ginkgo biloba L., and cell plugs of Ficus benjamina L. were grown in treatment containers for 5 months. A Minolta SPAD-502 was used to evaluate relative chlorophyll content as an indication of leaf tissue nutrient levels. Plant growth as a function of new growth dry weight was calculated. Soil samples were collected at the end of the study and were analyzed to evaluate the impact of humate admixes in nutrient availability. The fertilization treatments positively influenced leaf color and growth for all species. The CU soil control plants displayed significantly lower chlorophyll levels, but overall growth differences were less dramatic—insignificant in some cases. The humate additive did not consistently affect leaf color. The humate additive alone did not affect plant growth, but a significant positive interaction with the fertilizer treatment was evident for Platanus and Ficus. The positive interaction was insignificant in Salix and non-existent in Ginkgo.
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Bohner, Andreas, Silvia Winter, and Franz Starlinger. "Evaluation of different revegetation measures on mudflow deposits in the Nature Park Sölktäler (Styria, Austria)." Die Bodenkultur: Journal of Land Management, Food and Environment 71, no. 3 (September 1, 2020): 169–83. http://dx.doi.org/10.2478/boku-2020-0015.
Повний текст джерелаАнотація:
Summary In mountain regions, the likelihood of mudflows might increase due to climate change. Although mudflows are common worldwide and devastate agricultural land, virtually nothing is known about the revegetation of mudflow deposits for agricultural purposes. To provide recommendations for rapid revegetation of mountain pastures, 52 permanent plots (4 m × 4 m) on 20 revegetated mudflow deposits in the Nature Park Sölktäler were established. We evaluated different revegetation measures (seed addition alone or combined with application of straw, lime or cattle manure) two years after sowing using commercial clover-grass seed mixtures. Furthermore, 27 permanent plots on 15 unsown mudflow deposits were surveyed. Sowing seeds can considerably accelerate revegetation on siliceous mudflow deposits. Festuca rubra, Agrostis capillaris, Lolium perenne, Trifolium repens and Lotus corniculatus are particularly suitable for rapid grassland reestablishment, whereas Poa pratensis is not recommendable. A pure straw application should be avoided because it delays the revegetation success. Lime addition is not recommended because it can lead to an undesirable legume dominance if clover-grass seed mixtures are used for revegetation. The most effective measure for large-scale revegetation seems to be seed addition without additives. To facilitate revegetation on coarse-grained deposits, large rocks should be crushed using a stone mill.
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Tang, Van Lam, Boris Igorevich Bulgakov, and Olga Vladimirovna Aleksandrova. "DETERMINATION OF ADHESIVE STRENGTH LAYER’S ROLLER COMPACTED CONCRETE THE METHOD AXIAL EXTENSION." Vestnik MGSU, no. 6 (June 2017): 647–53. http://dx.doi.org/10.22227/1997-0935.2017.6.647-653.
Повний текст джерелаАнотація:
Roller compacted concrete for the construction of hydraulic and hydroelectric buildings is a composite material, which consists of a binder, fine aggregate (sand), coarse aggregate (gravel or crushed stone), water and special additives that provide the desired concrete workability and impart the required concrete performance properties. Concrete mixture is prepared at from concrete mixing plants strictly metered quantities of cement, water, additives and graded aggregates, whereupon they are delivered to the site laying Mixer Truck and sealing layers with each stack layer. The advantages of roller compaction technology should include the reduction of construction time, which allows fast commissioning construction projects, as well as reduce the amount of investment required. One of the main problems encountered in the process of roller compaction of the concrete mix is the need to provide the required adhesion strength between layers of concrete. This paper presents a method for determining the strength of adhesion between the concrete layers of different ages roller compacted concrete using axial tension. This method makes it possible to obtain objective and accurate results with a total thickness of layers of compacted concrete of up to 300…400 mm. Results from this method, studies have shown that the value of strength between the concrete layers in addition to the composition of the concrete and adhesion depends on the quality and the parallel end surfaces of the cylinder-models, which are mounted steel plates for axial tension, as well as the state of the contact surfaces of the concrete layer. The method can be used to determine the strength of interlayer adhesion in roller compacted concrete, which are used in the construction of dams and other hydraulic structures.
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Kuzmin, Mikhail P., Leonid M. Larionov, Marina Yu Kuzmina, and Vyacheslav G. Grigoriev. "Industrial uses of fluorogypsum." Journal «Izvestiya vuzov. Investitsiyi. Stroyitelstvo. Nedvizhimost» 9, no. 2 (2019): 324–33. http://dx.doi.org/10.21285/2227-2917-2019-2-324-333.
Повний текст джерелаАнотація:
The purpose of the study was to determine the possibility of obtaining Portland cement PC400 D20, which meets the requirements of GOST 10178–85, and uses fluorogypsum – a waste product of the hydrofluoric acid industry – as a source of gypsum feedstock. The object of the research was to study the physical and mechanical properties of Portland cement obtained by mixing crushed Portland cement clinker with active mineral (fly ash) with sulphate additives (gypsum stone or fluorogypsum). In terms of quality indicators, GOST 4913–82 fluorogypsum of JSC "Angarsk Electrolysis Chemical Plant", (JSC "AECC"), significantly exceeds the gypsum stone produced in the Nukutsky quarry (Irkutsk oblast). The high quality of the fluo-rogypsum produced by JSC "AECC" is due to the use of high-quality fluorite concentrate on the technologi-cal lines of hydrofluoric acid production. The composition of sludge fields of JSC "AECC" was investigated and the quality of its contents, fluorogypsum (a by-product of hydrofluoric acid production), was deter-mined according to an accredited classification. Studies of the chemical composition and physical proper-ties of fluorogypsum showed it can be classified as a first-grade raw material (GOST 4913–82) for the pro-duction of high-grade gypsum. Laboratory studies have confirmed the viability of using fluorogypsum as a substitute for natural gypsum stone in the production of cement, precisely when grinding cement clinker. A technology has been developed and parameters have been defined for the production of high-quality gyp-sum from fluorogypsum. Laboratory tests proved the possibility of using fluorogypsum in cement produc-tion as a setting regulator for grinding cement clinker. The exact dosage of fluorogypsum for grinding ce-ment clinker was determined, ensuring the production of high-quality cement fitting the GOST 10178–85. Studied approachesfor using fluorogypsum as a raw material for the production of high-quality gypsum are presented. Additionally, prospects for the production of a wide range of building mixtures based on fluo-rogypsum have been identified, which make it possible to gain a firm foothold in the market of high-quality dry building mixtures.
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Chan Min, Dat Le, Vadim B. Balabanov, and Maksim Yu Protsenko. "Use of hydrolytic lignin as a stabilising additive for crushed stone-mastic asphalt concrete." Journal «Izvestiya vuzov. Investitsiyi. Stroyitelstvo. Nedvizhimost» 9, no. 2 (2019): 334–41. http://dx.doi.org/10.21285/2227-2917-2019-2-334-341.
Повний текст джерелаАнотація:
The experience of using hydrolytic lignin in Russian and foreign literature allows it to be considered as a stabilising additive in the production of stone-mastic asphalt concrete mix. For thispurpose, it is necessary to conduct laboratory tests of raw materials and asphalt concrete mixtures with different percentages of hydrolytic lignin. Also, on the basis of the obtained results, to draw a conclusion about the use of waste from the hydrolysis industry for the building of the top layers of stone-mastic asphalt concrete coatings at the construction sites, reconstructions, major repairs and highways. Crushed stone-mastic asphalt concrete is an artificial road-building material, consisting of a mixture of mineral materials (crushed stone, sand from crushing siftings and mineral powder), oil road bitumen, used as a binding and stabilising additive for re-sistance to delamination and uniformity of crushed stone-asphalt concrete. Hydrolytic lignin is a polymer that makes up the walls of plant cells. The use of hydrolytic lignin as a stabilising additive for crushed stone-mastic asphalt concrete mixture allows to stabilise this mixture, to increase the adhesion of bitumen to the surface of the mineral material and to improve the physical and mechanical properties of crushed-stone-asphalt concrete. Based on the data obtained, the composition of crushed stone-mastic asphalt con-crete was developed using a stabilising additive from hydrolytic lignin. The use of hydrolytic lignin as a sta-bilising additive will improve the performance properties of crushed stone-mastic asphalt concrete, as well as reduce the cost of construction, reconstruction and overhaul of highways.
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Tran, Huu-Bang. "Mechanical Properties of Coarse Aggregate Electric Arc Furnace Slag in Cement Concrete." Civil Engineering Journal 7, no. 10 (October 1, 2021): 1716–30. http://dx.doi.org/10.28991/cej-2021-03091755.
Повний текст джерелаАнотація:
The feasibility of using EAF slag aggregate, fly ash, and silica fume in pavement Electric Arc Furnace Slag Concrete (CEAFS) is the focus of this research. EAF slag aggregate is volume stable and suitable for use in concrete, according to the findings of the testing. EAF slag was utilized to replace natural coarse aggregates in the CEAFS mixes. CEAFS was created by blending 50% crushed stone with 50% EAF slag in coarse aggregates, with fly ash (FA) and silica fume (SF) partially replacing cement at content levels (i.e. FA: 0, 20, 30, and 40%; SF: 0, 5, and 10%). The soil compaction approach was used to evaluate the optimal moisture level for CEAFS mixes containing EAF slag aggregate fly ash and silica fume. A testing program was used to investigate the weight of CEAFS units and their mechanical qualities (compressive strength, flexural strength, and elastic modulus). As a result, the fresh and hardened unit weights in the CEAFS are comparable. Moreover, variations in the concentration of mineral additives FA and SF in adhesives, as well as the CEAFS mixed aggregate ratio, have an impact on compressive strength, flexural strength, and elastic modulus at all ages. However, combining EAF slag aggregate with (FA0% +SF10%; FA10% +SF0%; FA10% +SF10%; and FA20% +SF10%) the CEAFS mixtures have improved mechanical characteristics over time. According to this study, CEAFS pavements can be made with EAF slag aggregate fly ash and silica fume. In addition, a formula correlation was suggested to compute CEAFS (i.e. compressive strength with elastic modulus and compressive strength with flexural strength). Doi: 10.28991/cej-2021-03091755 Full Text: PDF
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Leonovich, S. N. "Modeling of Capillary Shrinkage and Cracking in Early-Age Concrete." Science & Technique 17, no. 4 (July 31, 2018): 265–77. http://dx.doi.org/10.21122/2227-1031-2018-17-4-265-277.
Повний текст джерелаАнотація:
. Scientific hypothesis on moistening shrinkage mechanism for cement stone and concrete has been assumed as a basis for the present paper. Physical ideas on a mechanism for cracks volume increment in a concrete model presented as two-level structure have been accepted as a theoretical basis for a calculation method of crack resistance during capillary shrinkage. These ideas are the following: a matrix of hardening cement stone with inclusions and emptiness of various forms (cracks) as result of influences that change an intense deformed state in a point and a volume. The following assumptions have been accepted while making a theoretical justification for a calculation method of shrinkable concrete crack resistance. Following this methodology approaches of fracture mechanics according to a generalized criterion have been applied in the paper. Concrete is considered as an elastic quasi-homogeneous two-component medium which consists of the following parts:a) constructive part: a matrix – a cement stone with structural elements of crushed stone, sand; b) destructive part: emptiness – capillaries cracks and pores (cavities with initial cracks in walls). Emptiness in a matrix and contact zones are presented by a coordinated five-level system in the form and sizes which are multiple to a diameter due to impacts while reaching critical sizes. These critical sizes make it possible to pass from one level into another one according to the following scheme: size stabilization – accumulation delocalization – critical concentration in single volume – transition to the following level. Process of cracks formation and their growth are considered as a result of non-power influences on the basis of crack theory principles from a condition that fields of deformation and tension creating schemes of a normal separation and shift occur in the top part of each crack at its level in the initial concrete volume. Ксij(t) parameter as algebraic amount of critical values Kij in the whole system of all levels of cracks filling canonical volume up to critical concentration has been accepted as a generalized constant of property for concrete crack resistance in time, its resistance to formation, accumulation in volumes of micro-cracks and formation of trunk cracks with critical values. External temperature, moistening long influences create fields of tension in the top parts of cracks. Concrete destruction processes due to cracks are considered as generalized deformedintensed state in some initial volume having physical features which are inherent to a composite with strength and deformative properties. It is possible to realize analytical calculations for assessment of tension and crack resistance of concrete at early age on the basis of a generalized criterion in terms of stress intensity factor due to modern experimental data on capillary pressure value (70 kPa in 180 min after concrete placing). The developed algorithm of calculation allows to consider factors influencing on capillary pressure: type of cement, modifiers and mineral additives, concrete curing conditions.
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Medvedev, V. E., I. V. Filatova, and E. А. Girchenko. "Southern Boundaries of Osipovka Cultural Area." Problems of Archaeology, Ethnography, Anthropology of Siberia and Neighboring Territories 27 (2021): 188–94. http://dx.doi.org/10.17746/2658-6193.2021.27.0188-0194.
Повний текст джерелаАнотація:
The article concentrates on the Early Neolithic Osipovka culture of the Lower Amur and its southern boundaries. Due to the resumption of excavations at the Xiaonanshan site in the left bank of Ussuri River, Heilongjiang province, China, recently, it has become possible to conduct a comparative study of technical and typological characteristics of the ceramic material of these two territories. The following features were revealed: 1. Ceramics in both cases is loose, the composition of clay molding masses demonstrate the presence of additives: grus, sand, plant fibers, and crushed shell. 2. Prolonged low-temperature firing is typical of both territories. 3. Most common ceramic types are flat-bottomed vessels with a wide mouth of a truncated-conical shape. 4. The surface of the vessel was first covered with a reddish clay engobe, then with an ornament, and the authors also recorded the traces of smoothing the surface with grass. 5. Vessels were ornamented by narrow parallel grooves or grooves with a flat path between the edges made with a hard comb instrument. 6. The rim was ornamented with dissected narrow depressions or through holes. Among the investigated stone tools, bifacial spearheads and arrows as well as sinkers of various shapes prevail, which indicates that the economy of both Osipovka culture bearers and the inhabitants of the Xiaonanshan site were based on a combination of fishing and hunting. The revealed similarities probably indicate that these materials represent a complex of cultures of a single areal. Moreover, the artifacts found at the Xiaonanshan site show definite differences from other materials found in northern China and differ significantly from the traditions typical for the Middle Yellow River or the Yangtze Valley. Probably, the south-west of the Lower Priamurye, the wide-known autochthonous center of ancient pottery, could be a zone of contacts of this region and both more southern and more eastern territories. The Osipovka influence went beyond the Amur region, which is very important for understanding the processes of Neolithization in the North East Asia.
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Rudenko, Konstantin A., and Evgeniy P. Kazakov. "Komintern III Settlement of the Golden Horde Epoch in Tatarstan." Povolzhskaya Arkheologiya (The Volga River Region Archaeology) 4, no. 42 (December 23, 2022): 101–12. http://dx.doi.org/10.24852/pa2022.4.42.101.112.
Повний текст джерелаАнотація:
The paper deals with the materials of one of the settlements of the Golden Horde epoch – the III Komintern settlement, located in the Spassky district of the Republic of Tatarstan. The settlement occupies the edge of the above-meadow terrace of the Aktay River. Together with the II Komintern settlement it was a large rural center associated with handicrafts and trade. Unfortunately, a large part of the settlement was destroyed by waters of the Kuibyshev reservoir and all artefacts collected in the 1960s – early 2000s and published in this paper were found on eroded cultural layer. As the analysis of the material has shown, the III Komintern settlement was a craft part of this settlement and a pier where goods were unloaded. The peculiarity of its material culture is in a large number of fragments of cast-iron cauldrons. They are represented by standard forms (types Ч-3 m Ч-4), as well as a rare type – Ч-9, with three legs, having analogies in Chinese and Far Eastern materials of the 12th – 14th centuries. Pottery is represented by fragments of jugs, pots, bowls. Hand-made and corrected on a wheel pottery (bowls, pots, etc.) contains additives to clay: sand, crushed stone and dry clay. There is a group of so-called "Slavonic type" ceramics, typical for the sites of the second half of the 14th century. In other respects, the finds are characteristic of settlements that existed during the late 13th – early 15th centuries. The Komintern archaeological complex is interesting because it demonstrates the dynamics of the development of flood-plain settlements on the Lower Kama and their material culture throughout the Golden Horde period. It evolved from the Peschany Ostrov type settlement that appeared at the end of 13th – beginning of the 15th century to a trade and craft settlement during the middle – second half of the 14th – beginning of the 15th century.
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BEPPAEV, Zamir, Lidia ASTVATSATUROVA, Sergey KOLODYAZHNIY, Sergey VERNIGORA, and Vladislav LOPATINSKIY. "RESEARCH OF THE DEPENDENCE OF THE GRAIN SIZE COMPOSITION AND GRADE OF CRUSHABILITY OF RECYCLED CRUSHED STONE ON THE STRENGTH OF THE ORIGINAL RECYCLED CONCRETE." Bulletin of Science and Research Center “Stroitelstvo”, no. 3 (30) (July 30, 2021): 5–16. http://dx.doi.org/10.37538/2224-9494-2021-3(30)-5-16.
Повний текст джерелаАнотація:
The results of the study of the grain-size composition and the grade of crushability of recycled crushed stone and their dependence on the strength of the original recycled concrete are presented. It is found that recycled crushed stone obtained from the original concrete of classes B10 - B30 does not meet the requirements of GOST 8267-93 for total residues on Ø25, Ø20, Ø5 and Ø2.5 sieves. Regardless of the strength of the original concrete, the main fraction of recycled crushed stone is grains with sizes from 12.5 to 20 mm. The strength (grade in terms of crushability) of the recycled crushed stone increases with an increase in the strength of the original concrete. The study of the main parameters of recycled crushed stone at the current moment has been carried out in an insufficient (for widespread introduction into production) volume and requires further study for the subsequent development of independent regulatory and technical documentation (or additions to the current regulatory and technical documents).
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Kuncoro, Kuncoro. "OPTIMASI MIX DESIGN K 350 PADA BETON PRECAST." Jurnal Ilmiah MITSU 7, no. 2 (October 24, 2019): 5–7. http://dx.doi.org/10.24929/ft.v7i2.720.
Повний текст джерелаАнотація:
Saat ini harga semen semakin mahal. Kompetisi diantara produsen beton pracetak semakin Meningkat khususnya produksi box culvert. Keinginan sebagian besar pasar adalah box culvert Yang memenuhi standar strength/kekuatan yang denganpenekanan biaya produksi. Rekayasa Mix Design ini bertujuan untuk menurunkan semen content dan mempertahankan kekuatan Beton serta menurunkan biaya produksi. Penelitian ini dilakukan dengan melakukan rekayasa Atau optimasi pada pemakaian semen konten dan subtitusi abu batu terhadap Pasir Lumajang Pada campuran beton K-350. Hasil penelitian yang paling efisien adalah menggunakan semen Sebanyak 325 kg, natural sand 530 kg, dust stone 230 kg, crushed stone 1-2 795 kg, crushed Stone 5-10 340 kg, air 83,51 liter, additive consol N15 4,6 liter. Efisiensi yang didapat dari mix Design tersebut adalah sebesar Rp. 47.692 ,-/m3.
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Bieliatynskyi, Andrii, Shilin Yang, Valerii Pershakov, Meiyu Shao, and Mingyang Ta. "Study of concrete properties based on crushed stone sand mixture and fiber of fly ash of thermal power plants." Science and Engineering of Composite Materials 29, no. 1 (January 1, 2022): 412–26. http://dx.doi.org/10.1515/secm-2022-0167.
Повний текст джерелаАнотація:
Abstract The study aims to optimize the composition of the main composite, the components of which, in their joint presence, make it possible to obtain the most significant positive synergistic effect. The authors of this article used the fibers of fly ash from thermal power plants as a finely dispersed component added to the crushed stone sand mixture. The result of the study was a high-strength corrosion-resistant material consisting of a crushed stone sand mixture (CSSM) with the addition of the fibers of fly ash. The authors applied the thermogravimetric and standard methods to study and determine the performance and strength characteristics of the obtained material. The combined effect of a complex organic-mineral modifying additive and the cement with the fibers of fly ash provided a compacted and reinforced structure of cement stone. An optimal binder composition was developed, consisting of cement and fiber of fly ash. The authors of this article examined the physical-mechanical and structural-mechanical properties of a CSSM of fine-grained concrete reinforced with a complex additive of cement, fibers of fly ash, and a superplasticizer. The study also provided technological solutions for manufacturing a functional mixture of fine-grained concrete based on the developed complex organic-mineral additive.
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Fediuk, R. S., A. V. Baranov, D. V. Khromenok, I. R. Zelenskiy, and S. V. Kim. "CEMENT STONE STRUCTURE COMPACTION WITH COMPOSITE BINDER." Vestnik Tomskogo gosudarstvennogo arkhitekturno-stroitel'nogo universiteta. JOURNAL of Construction and Architecture, no. 3 (June 27, 2019): 195–206. http://dx.doi.org/10.31675/1607-1859-2019-21-3-195-206.
Повний текст джерелаАнотація:
The aim of the paper is to improve the strength properties of cement stone via control for structure formation. The composite binder composition includes the type CEM I 42.5N (58–70%) Portland cement, active silica additive (25–37%), quartz sand (2.5–7.5%) and limestone crushed waste (2.5–7.5%). The optimum technology of mechanochemical activation is proposed for the cement stone. The optimization of the structure formation process is provided by the mineral-mineral modifier, crushed together with Portland cement in a planetary mill to a specific surface of 550 m2/kg. The amorphous phase of silicon dioxide in the composition of the modifier intensifies the calcium hydroxide binding forming during alite hydration. It contributes to the growth in low-basic calcium silicate and lowers the cement stone basicity, while reducing the amount of portlandite. The crystalline phase of β-quartz silicon dioxide plays the role of crystallization centers new formations and the cement stone microstructure compaction. Limestone particles contribute to the formation of calcium hydrocarbonate and act as a microfiller together with fine ground quartz sand clogging the pores in the cement stone.
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Gunel Mammadova, Gunel Mammadova, Nahida Jafarova Nahida Jafarova, and Mehpara Sadigova Mehpara Sadigova. "PREPARATION OF CONCRETE BASED ON GLASS WASTE." PAHTEI-Procedings of Azerbaijan High Technical Educational Institutions 13, no. 02 (March 1, 2022): 72–79. http://dx.doi.org/10.36962/pahtei13022022-72.
Повний текст джерелаАнотація:
The article discusses the study of the properties of high-strength concrete based on glass waste. The main purpose of this dissertation is to show the possibility of using glass fragments as a concrete filler, to study the physical and mechanical properties of the obtained concrete and to clarify its application in construction. The urgency of the work is currently characterized by the widespread use of high-tech new generation concrete in the field of construction - modified high-strength concrete. Due to the high cost of natural raw materials, it is especially important to conduct research that reveals new opportunities for the use of waste in the creation of new construction materials. Increased attention is paid to the disposal of industrial and domestic waste. This is necessary, especially in large cities, where the environmental situation is deteriorating. However, there are types of glass that are recycled or considered unfit for recycling, are difficult to process, and require high costs, and their waste still occupies landfills. This type of waste can be successfully used in the preparation of construction materials. In recent years, the effective use of glass waste in the production of high-strength concrete composites has been found in foreign literature As a fine aggregate selected for the study, a mixture of construction sand taken from the Shikhlar sand deposit of Absheron and waste sand from rock quarries was used. Glass waste - The scale of glass waste generation is very large. Industrial waste is 0.32 million tons per year. In addition, glass accounts for 5-7% of the total volume of solid waste, which is about 1.3 ... 1.9 million tons per year. We used waste-crushed granite concrete gravel as a filler for concrete. Granite gravel with 5-10 and 10-20 mm fraction was used as a filler for concrete. Experiments for the study were conducted in 2 directions. In the first case, very fine glass powder was used for the experiments. Granite gravel with a fraction of 5-10 mm was used for the production of first-class concrete samples using glass waste as a filler for the taken concrete samples, natural sand and glass waste with a grain size of 0-10 mm from the Shikhlar field of Absheron were used as a fine filler. Row II of the concrete samples was also prepared for testing to increase strength. Crushed granite with a fraction of 5-10 mm, crushed granite sand with a size of 0-10 grains and glass fragments were used as aggregates for this series of samples. Like all materials, microsilicate reacts with calcium hydroxide Ca (OH) 2 formed during the wetting of Portland cement in the process of wetting the binders. The high purity and increased dispersion of microsilicate contributes to a more efficient and faster reaction, which depends on the composition of the reactive silicon. Silicon mist, together with effective superplasticizers, can provide compression resistance many times higher than ordinary concrete. The average value of microsilicate water suspension is 7.74 . The fineness of microsilicate can be compared with the fineness of other powdered materials: microsilicate - 140000 - 300,000 sm2 / g, volatile ash - 4000 - 7000 sm2 /g, Portland cement - 3000 - 4000 sm2 / g. The use of microsilicate helps to reduce cement consumption up to 200 - 450 kg / m3, has a high compressive strength: 60 - 80 MPa and above 80 MPa for fine-grained concrete, increases anti-corrosion resistance, reduces water resistance by 50%, buda concrete increases durability. The object of this research is the technology of preparation of high-strength concrete based on glass waste. Experiments have shown that when fine natural aggregate is replaced with glass waste, the strength of concrete decreases due to the lack of adhesion between the glass-cement stone particles. The amount of glass waste in fine natural sand is 30% of Shikhlar-Absheron deposit When used as a fine aggregate, gravel sand made of durable granite does not affect the strength of concrete by replacing 15% of the sand with a glass mixture. And only more than 30% of the glass waste in the sand can reduce the strength of concrete. When the crushed sand is completely replaced with glass waste, a maximum reduction in the strength of the concrete is obvious. The addition of a number of additives can change the properties and quality of concrete containing glass fragments. Today, water-resistant concrete products based on the composition of glass fragments are widespread. This type of concrete product meets the most advanced technological requirements. Also, this concrete is composed of environmentally friendly natural and clean elements, and this product is now widely used. As a result of the study, the study of the properties of high-strength concrete based on glass waste is discussed. Various glass wastes are used in construction to increase the strength of concrete composites and prevent environmental pollution. Keywords: glass waste, high-strength concrete, recycle, composite, granite waste.
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Khezhev, Tolya, Aslan Kardanov, Eldar Bolotokov, Azamat Dottuyev, and Ibrahim Mashfezh. "Fine-Grained Fibre Concrete of Run-Of-Crusher Stone Using Volcanic Ash." Materials Science Forum 1043 (August 18, 2021): 61–65. http://dx.doi.org/10.4028/www.scientific.net/msf.1043.61.
Повний текст джерелаАнотація:
The results of the studies on the creation of self-compacting fine-grained fiber-reinforced concrete based on run-of-crusher stone with the use of a polyfunctional additive D-5 are presented. Compositions of self-compacting fine-grained fiber-reinforced concrete with the use of basalt fiber have been developed, which significantly reduce cement consumption and improve the characteristics of fine-grained concrete mixture and concrete. Using a polyfunctional additive D-5in mixtures makes it possible to increase the strength properties of fine-grained fiber-reinforced concrete while improving the concrete mixtures’ rheological characteristics. Replacement of cement up to 10% of the mass by ash fraction d<0.14 min fine-grained concrete mixtures does not cause a noticeable decrease in the concrete strength properties. The developed self-compacting fine-grained fiber-reinforced concretes have increased strength properties and have a low-cost price due to the use of local raw materials and run-of-crusher stone.
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Szabó, Bence, L. Pásthy, Á. Orosz, and K. Tamás. "The investigation of additive manufacturing and moldable materials to produce railway ballast grain analogs." Frattura ed Integrità Strutturale 16, no. 60 (March 25, 2022): 213–28. http://dx.doi.org/10.3221/igf-esis.60.15.
Повний текст джерелаАнотація:
The size and shape of individual grains, play an important role in the mechanical behavior of granular materials such as the strength and stability of railway ballast. The aim of this research is to study materials from which uniform, reproducible grains with irregular convex geometry can be created by molding and additive manufacturing technologies in order to create reproducible artificial assemblies that can be used in experiments. Packings with determined grain shape results more controlled investigations contrarily to using natural grains with random geometry. Specimens were made from railway ballast materials, materials used in the construction industry, additively manufactured and molded polymers, and certain low-strength materials. Uniaxial compression and bending tests were conducted on these specimens. The mechanical properties of typical railway ballast materials (basalt and andesite) were compared with the properties of artificially produced materials. The results show that for grain reproduction the molding technology is recommended with the use of polyester-crushed stone composite and ceramic powder. Furthermore, the additive manufacturing was recommended with PolyJet or Multi Jet Fusion technology as they have the feasibility to produce grains with similar material properties to the properties of basalt and andesite.
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Konovalova, Nataliya A., Pavel P. Pankov, and Dmitry V. Bespolitov. "Minimization of the impact of rubble production wastes on the environment by their involvement in the compositions of road'building materials." RUDN Journal of Ecology and Life Safety 29, no. 1 (December 15, 2021): 82–91. http://dx.doi.org/10.22363/2313-2310-2021-29-1-82-91.
Повний текст джерелаАнотація:
The impact of Taldan crushed stone plant and wastes formed in process of its activity on the environment is considered. About 2.9 million tons of siftings of rock grinding were accumulated in dump massifs with a total area of 600 hectares. Therefore, elimination of accumulated harm to the environment that has arisen over many years of operation of Taldan crushed stone plant is the actual task. One of the technological solutions of liquidation of objects of accumulated harm to the environment based on physicochemical impact on wastes is stabilization or artificial stone formation. Drawing of siftings of rock in soil concrete compositions (artificial stone materials) allows to solve complex of acute environmental problems due to their largetonnage direct use. The use of siftings of rock in road building will contribute to the rational and cost-effective use of natural mineral raw materials, since this process will not entail an increase in the costs of its extraction and processing. A set of modern methods (atomic-emission spectrometry with inductively coupled plasma, scanning electron microscopy, X-ray phase analysis, infrared spectroscopy) were used to study the chemical, phase composition and properties of siftings of rock to substantiate the possibility of its utilization in the composition of soil concrete. It is shown that the introduction of an 8 wt. % of mineral binder and polymer stabilizing additive Element (1, 5, 10 wt. %) allows to get soil concrete with a mark of strength М100.
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Junior, Antonio Rodrigues Pantoja, and Marcelo Picanço. "CONCRETO PRODUZIDO COM AGREGADO GRAÚDO LATERÍTICO EM SANTARÉM, PARÁ." REEC - Revista Eletrônica de Engenharia Civil 16, no. 1 (June 4, 2020): 60–77. http://dx.doi.org/10.5216/reec.v16i1.61937.
Повний текст джерелаАнотація:
RESUMO: Avaliou-se a substituição da brita basáltica existente no concreto por material alternativo em abundância no município de Santarém-PA: a laterita. Foi avaliado o desempenho do concreto incorporado com agregado laterítico in natura em substituição parcial ao agregado graúdo de brita basáltica nos teores de 20% e 50%. Realizou-se a caracterização dos agregados graúdo e miúdo. De acordo com o método da ABCP, determinou-se o traço de referência em massa 1:1,71:3,03:0,53; confeccionou-se corpos-de-prova cilíndricos 10x20 cm utilizando 3 traços diferentes, de modo a substituir a brita basáltica pelo agregado laterítico, em 20% e 50%. Para cada traço foram quantificados a sua consistência, por meio do ensaio de abatimento do tronco de cone, resistência à compressão axial, resistência à tração por compressão diametral e módulo de elasticidade aos 28 dias. A substituição do agregado convencional de brita basáltica por agregado laterítico em seu estado natural promoveu diminuição da resistência a compressão simples, da resistência à tração por compressão diametral e do módulo de elasticidade com a inclusão do agregado laterítico na mistura. Destaca-se que acima de determinado teor de substituição o concreto torna-se inviável devido a necessidade de adicionar aditivo plastificante para manter a consistência desejada e que as duas misturas incorporadas com agregado laterítico se mostraram muito semelhantes após os 28 dias, no que tange a ganhos de resistência a compressão.
ABSTRACT: This study is about the replacement of basaltic origin crushed stone by alternative material present in the municipality of Santarém, Pará State: the laterite. The aim were to evaluate the performance of concrete incorporated with natural lateritic aggregate, replacing the of crushed stone in 20% and 50%. The first stage was characterizing the coarse and fine aggregates that made up the studied concrete. According to ABCP dosing method it was determined the mass reference trait 1: 1.71: 3.03: 0.53; bodies of 10x20 cm were made for cylindrical test, using three different strokes so that the basaltic crushed stone gradually replaced by the lateritic aggregate in proportions of 20% and 50%. For each trait its consistency was quantified by means of the tapering test, axial compression strength, diametric compression tensile strength and the modulus of elasticity at 28 days. Was observed that the replacement of the conventional aggregate basalt crushed stone for aggregate of laterite in natural state promoted a decrease in the value of simple compressive strength, diametric tensile strength and modulus of elasticity with inclusion of a larger amount of lateritic aggregate in the mixture. It is noteworthy that above a certain substitution content, the concrete becomes not feasible due to the need for a large increase in the amount of plasticizer additive to the desired consistency is maintained and the two blends incorporated with lateritic showed very similar after 28 days in terms of gains in compressive strength.
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Zayakin, Oleg V., and Ilia N. Kel'. "Promising Directions for the Stabilization of Ferroalloy Production Slags." Materials Science Forum 946 (February 2019): 401–5. http://dx.doi.org/10.4028/www.scientific.net/msf.946.401.
Повний текст джерелаАнотація:
In this paper the analysis of the processes for spontaneous decay of slags from the production of refined ferroalloy grades is performed. It is shown that the main reason for the decay is the formation of a dicalcium silicate in highly basic melts with CaO / SiO2 ratio of 1.5-3.1. Based on the performed studies, three main promising directions for the stabilization of slags of ferroalloy production have been formed. First direction is the replacement of the calcium cation (or transformation) in a dicalcium silicate, for example, with the magnesium cation or the production of non-decaying compounds of the gehlenite type (2CaO·Al2O3·SiO2), mainly due to the application of phase composition peculiarities of the waste rock for ferroalloy raw materials. Second direction is the reduction of the dicalcium silicate content with a decrease in the ratio of CaO / SiO2 in the slag less than 1.4, due to the separation of the silicothermic reduction process into two stages, obtaining in the first stage a low-basic (CaO / SiO2 = 1.3-1.4) non-decaying tailing slag, and on the second one - highly basic return slag (1.8-1.9), which is used in the first stage of this technological chain. The third direction is the replacement of the SiO anion of dicalcium silicate with other anions, for example, ВО by means of small additions of calcium borate, colemanite, etc. A possibility for stabilization of ferroalloy production slags with obtaining of construction crushed stone corresponding to the requirements of TU 0798-69-00186499-2014 "Crushed stone and sand from ferroalloy slags. Technical conditions», is shown experimentally.
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Grabosky, Jason, and Nina Bassuk. "192 Growth Response of Salix nigra Marsh. to Fertilization, Humate Additive, and Mycorrhizae Inoculation in a CU Soil Container Study." HortScience 35, no. 3 (June 2000): 424A—424. http://dx.doi.org/10.21273/hortsci.35.3.424a.
Повний текст джерелаАнотація:
CU soil is a material primarily composed of clay loam soil and crushed stone designed for use under pavement to promote street tree root growth in a durable pavement section, such as sidewalks or parking lots. One concern is the low total soil fraction from which tree roots can meet nutritive demands. At issue is the long-term nutrient management of street trees once the root zone has been rendered inaccessible due to the pavement wearing surface, although in 3-year field tests, there were no differences found between a CU soil material and an agricultural field control. CU soil treatments were produced in a fractional factorial design with a patent applied for, processed humate additive, a nursery production fertilization treatment, and a mycorrhizae inoculation package of Pt and various VAM species. The mycorrhizae/fertilizer treatment was eliminated for plant availability restrictions. Bare-root seedlings of Salix nigra Marsh. were grown in treatment containers for 5 months. A Minolta SPAD-502 was used to evaluate relative chlorophyll content as an indication of leaf tissue nutrient levels. Plant growth as a function of root dry weight, shoot dry weight, and shoot: root ratio was analyzed. Soil analyses were conducted on media samples collected at the end of the study to evaluate the impact of humate admixes in nutrient availability. The fertilization treatments positively influenced leaf color, shoot weight, root weight, and shoot: root ratio. There was no impact from the mycorrhizae inoculation on leaf color or growth. There was no impact from the humate additive on leaf color or growth. There were no additive effects found in the treatment levels.
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Ibraimova, Saniya, Raushangul Uazhanova, Ayana Serikbaeva, and Maryna Mardar. "Application of the principles of international standards to ensure quality and safety in the development of technology of bakery products of increased nutritional value." EUREKA: Life Sciences, no. 4 (July 30, 2021): 19–26. http://dx.doi.org/10.21303/2504-5695.2021.001974.
Повний текст джерелаАнотація:
In order to manage quality and safety in the development of technology for new types of bakery products of increased nutritional value, the HACCP system was used.
Marketing research has shown that consumers would like to see more nutritious breads with natural additives on store shelves. Juniper (Juniperucommunis L) is one of the traditional crops growing in Kazakhstan and characterized by a high content of biologically active substances. In this regard, 3 % of crushed juniper fruits were added to the bread recipe.
In the course of research, a HACCP plan was developed for a new type of bread with increased nutritional value with the inclusion of juniper. As a result of the analysis of the bread production process, hazardous factors were identified and safety management measures were determined. Three critical control points were identified – during preparation (cleaning and grinding) of juniper fruits, during dough fermentation, and during storage of finished products. Once risk factors were identified, critical limits were identified, a monitoring procedure was established, and corrective actions were developed. The developed HACCP plan was tested at an enterprise for the production of bakery products, which led to an increase in the safety of products, and, accordingly, to an increase in its competitiveness in the consumer market of Kazakhstan.
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Eroshkina, Nadezhda, Mikhail Chamurliev, and Mark Korovkin. "Sulfuric acid corrosion of geopolymer concrete with mineral additives from wastes." Russian journal of transport engineering 6, no. 3 (September 2019). http://dx.doi.org/10.15862/27sats319.
Повний текст джерелаАнотація:
The effect of mineral additives such as crushed ash and individual building demolition waste on the corrosion resistance of geopolymer concrete based on screening the crushed granite and blast furnace slag in an environment of sulfuric acid solutions was studied. The corrosion resistance of concrete was evaluated by the kinetics of reducing the mass and strength of samples in sulfuric acid solutions with a concentration of 2,5 and 5 % for 10 days. It was shown that replacing 50 % of granite powder with ground crushed bricks or ash significantly increases the corrosion resistance of geopolymer materials. It was established that due to the formation of poorly soluble products of the interaction of sulfuric acid and concrete in the pores of a geopolymer stone, an interface is formed between the undestructed material and the zone subjected to destructive processes, which impedes the penetration of the corrosive medium into the material. The study also conducted comparative studies of the corrosion resistance of Portland cement concrete with various water-cement ratios. The research results showed that under the influence of sulfuric acid in Portland cement concrete this border does not form and a rapid loss of mass and strength occurs in the samples. The established feature of the process of destruction of geopolymer concrete in a solution of sulfuric acid is the reason for its higher resistance in comparison with cement concrete.
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Jain, Vaibhav, Gaurav Sancheti, and Bhupesh Jain. "Non-destructive test analysis on concrete with rice husk ash and crushed stone additives." Materials Today: Proceedings, February 2022. http://dx.doi.org/10.1016/j.matpr.2022.02.128.
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Stroev, Dmitry, Sergey Sizonets, and Vanik Kazaryan. "Strengthening the pavement bases through the use of stabilizing additives." Russian journal of transport engineering 5, no. 4 (2018). http://dx.doi.org/10.15862/08sats418.
Повний текст джерелаАнотація:
The experience of recent years of road operation shows that one of the ways to reduce the accumulation of residual deformations in the layers of road construction, expressed in rutting, the appearance of a grid of cracks and other types of transverse and longitudinal irregularities, is used in the base layers of pavements reinforced with mineral binders of crushed-stone-gravel-sandy mixtures (HGPS). The strength and deformability of hardened HGPS is determined mainly by the structure and properties of the cement stone, which holds the aggregate grains in place. The structure and properties of reinforced HGHPs depend on: the mineralogical composition, the water-cement ratio, the fineness of the cement, the age, the preparation and hardening conditions, or the addition of additives. With the introduction of additives, you can significantly change the strength and deformability of reinforced HGPS. Currently, stabilizing additives are widely used, the introduction of which allows to provide high water resistance, crack resistance and durability of the structural base layer. At the same time, a reinforced mixture with the use of additives has not only all the positive properties of HGPS on portland cement, but also eliminates its negative sides: low values of compressive strength, tensile strength in bending, and large shrinkage deformations. Based on the above, the introduction of stabilizing additives in fortified HGPS seems to be fruitful. As an additive, the stabilizer «ARMADOR» was used. The additive is a dry bulk mixture based on polymers, salts of alkali and alkaline earth metals. With the introduction of the stabilizer «ARMADOR», the physico-mechanical parameters increase in the composition of the reinforced material. This stabilizer creates strong crystallization and coagulation bonds, the use of which is recommended in conjunction with a mineral binder.
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"Compressive Strength of Concrete with Construction and Demolition Waste and m-SAND using Additives." International Journal of Recent Technology and Engineering 8, no. 2S10 (October 11, 2019): 935–37. http://dx.doi.org/10.35940/ijrte.b1156.0982s1019.
Повний текст джерелаАнотація:
Construction and Demolition wastes(C&D wastes) are generated in all cities of the world due to rapid urbanization. Disposing C & D waste these days is a costly affair, and raises environmental issues. Hence an attempt is made to reuse the demolished concrete as a partial replacement of natural coarse aggregates. Also due to ban of sand mining by local authorities, the cost of natural fine aggregate is very high and itself becoming a scarce material. Hence crushed stone aggregates called manufactured sand (m sand) is used, totally replacing natural fine aggregates. This concept is found to be cost effective, minimizes disposal of C & D wastes, and leads towards Green Building Concepts. Compression test on M40 concrete cubes of size 150mmx150mmx150mm are conducted at end of 7 days and 28days. Mix design for M40 concrete is made in accordance to IS: 10262-2019 with water cement ratio of 0.45 using 53 Grade Ordinary Portland cement. Superplasticizer (LIQUIFIX) is used to enhance workability. Nano Silica (NS)(1.5% by weight of cement),Wollastonite powder(WP)(10%by weight of cement) and Basalt fibres(BF)(1% by weight of cement) are added as additives. It is observed, that compressive strength of 7 days and 28 days cured samples is 25% more with the addition of all three additives compared to samples without additives. Hence the loss of compressive strength obtained by using demolished concrete as aggregates and m sand in concrete is regained with the addition of additives.
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Matyevav, Аrbermet, Tolkunbek Keneshbek u., and N. Sayitkaziev. "ARBOLITE FROM LIGHT-WEIGHT CONCRETE." Science and Innovative Technologies, May 5, 2019, 27–37. http://dx.doi.org/10.33942/sit005.
Повний текст джерелаАнотація:
Thispaperinvestigates the technology of energy and resource saving materials, involving the use of local raw materials of plant origin as a filler (aggregate) material, and the alkali base composition as a binder material. Fillers(aggregates)have a significant impact on the technological and operational properties, as well as on the process of structure formation of plant-binding composites.The introduction of Portland cement, construction gypsum, ash and structure-forming additives and polymer silicate compositions with plasticizers in a plant-binding composition (PBC) contributes to the enhancement of the strength properties and obtaininga cement-gypsum-alkali binder with improved technical and mechanical characteristics on their basis and properties. To obtain arbolitewith higher strength, thermal characteristics, it is necessary to completely eliminate the influence of extractive substances of organic fillers (aggregate)on the cement stone, increase the adhesion of organic aggregate with a mineral binder material and modifying additives.According to obtained results on the base ofscientific studiesand researchesondeterminationof the composition and properties of arbolitematerials using crushed rice straw, the possibility of developing arbolitewall blocks based on the developed new building technologies has been established.
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Cuong, Dinh Van, Tran Van Thanh, and Tuan Nguyen Anh. "Study on the possibility of using artificial pillar to replace the protection coal pillar of the preparation roadways during the mining process at underground coal mines in Quang Ninh region, Vietnam." Inżynieria Mineralna 2, no. 2 (January 13, 2022). http://dx.doi.org/10.29227/im-2019-02-73.
Повний текст джерелаАнотація:
The coal reserves in protection pillar of roadways are expected to be left in the mining processin underground mines in Quangninh coal basin which is relatively large (about 16% of the total reserves).If it can be exploited, it will help to save non-renewable coal resources, reduce the cost of preparingroadway meters, extend the mine life and increase the efficiency of construction investment. In the world,in order to reduce coal loss in protection pillar of roadways, mining technology to exploit and use artificialprotection pillars are quite popular. Accordingly, in order to simultaneously exploit coal in the protectionpillar and maintain the transport roadway as a ventilation roadway for the longwall in below level, thepost-mining coal pillar will be replaced by artificial pillars formed from the stone backfill cribs, columns,metal cribs, chemical materials or low-grade concrete mortar mixes formed from fly ash, bottom ash ofthermal power plants, combined crushed waste rock and a cement additive,... This paper will evaluate thepossibility and propose a number of mining technological scheme as well as the type of constructionmaterials suitable for artificial columns.