scholarly journals Effect of ash-and-slag waste on the properties of sulphoaluminate portland cement

Vestnik MGSU ◽  
2019 ◽  
pp. 991-1003
Author(s):  
Tang Van Lam ◽  
Nguyen Doan Tung Lam ◽  
Svetlana V. Samchenko
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Setting Time ◽  
Microscopic Analysis ◽  
Silica Sand ◽  
High Dispersion ◽  
Fine Aggregate ◽  
Electron Microscopic ◽  
Ash And Slag Waste ◽  
Slag Waste

Introduction: there is practically no information on the utilization of ash and slag waste (ASW) application in technology of special (noncontracting, expanding, self-stressing) cements, which predetermines the relevance of research in this direction. The study investigates the properties of experimental samples from cement, ash-and-slag and sand mixtures based on sulphoaluminate Portland cement (SAC) with an additive of the ASW. Materials and methods: a fine-particle binder material consisting of the SAC produced by the Podolsk Cement factory with a fine-grained ASW additive was used to obtain a binder mixture. Silica sand functioned as fine aggregate. All the raw materials used were local to the Russian Federation. The setting time, soundness, and strength of the binder mixture were determined according to GOST 30744-2001 standard. The specific surface area of the Portland cement was established through the use of the air permeability method utilizing of PMTs-500 instrument. The microstructure of the hardened binder mixture was studied employing electron microscopic analysis and X-ray phase analysis. Results: the work investigates the effect of 10 %, 15 %, 20 %, and 50 % ASW additive on the water demand, strength, and setting time of the SAC. The article also explores the kinetics of hardening and structure formation of samples from the binder mixture based on the SAC and ASW for hardening under normal conditions. Conclusions: results of the investigation allow recommending the ASW characterized by high dispersion as an additive for production of special cements without significant reduction of their properties. In the presence of the ASW, setting times of the cement mixtures virtually do not change as compared with the pure SAC. With limiting the amount of the ASW in the composition of the Portland cement, the strength characteristics do not practically change through the entire period of hardening.

scholarly journals Plasma modification of construction mortar components, an efficient method of increasing their performance

Vestnik MGSU ◽  
2019 ◽  
pp. 548-558
Author(s):  
Anton Yu. Kalyadin ◽  
Grigor V. Nalbandyan ◽  
Vadim G. Soloviev ◽  
Anfisa A. Bogdanova ◽  
Valentin A. Ushkov
Keyword(s):  
Phase Composition ◽  
Portland Cement ◽  
Plasma Treatment ◽  
Granulometric Composition ◽  
Raw Materials ◽  
Setting Time ◽  
Silica Sand ◽  
Plasma Modification ◽  
Mechanical Parameters ◽  
Mixing Water

Introduction. The article considers the enhancement of physical and mechanical parameters of construction mortars used for recovering and repairing of building structures of communication collectors by using low-temperature nonequilibrium plasma. The study vindicated the expediency of treatment of construction mortar raw materials with LTNP to enhance their physical and mechanical parameters. The effect of plasma modification of raw materials on Portland cement phase composition, granulometric composition of the sand and mortar properties are analysed. The influence of multiplicity of silica sand and mixing water plasma treatment on the construction mortar strength is considered. Materials and methods. Cement-sand mortars are obtained from Portland cement of the CEM I 32.5N and CEM I 42.5N brands and silica sand with the fineness moduli of Mf = 0.32 and Mf = 0.63 and a separate fraction of less than 0.16 mm. Setting time and strength of the building mortars are defined according to GOST state standards in effect. Granulometric composition of the cement is explored by means of Analysette-22 particle size microanalyser, while ARL Optim’X spectrometer is used for studying phase composition of the cement stone, silica sand and cement-sand mortars. Results. It is determined that the plasma treatment of Portland cement reduces the grout normal consistency by 15 to 17 % and decreases its setting time by a factor of 3 to 4. Treatment of mixing water with the nonequilibrium low-temperature plasma removes its hardness, forming additional crystallization nuclei. The plasma-treated mixing water increases the curing rate of cement-sand mortars up to 50 % at the early stages of hardening and up to 30 % on the 28th day of hardening. Using plasma-treated silica sand decreases size of its particles and results in partial transition of the crystalline structure into the amorphous one. This reduces water demand of the sand by 10 to 18 %. Conclusions. The expedience of plasma treatment of raw materials to enhance the physical and mechanical properties of mortars is vindicated. Owing to the plasma modification of raw materials, quality and process characteristics of construction mortars are improved. The presented method of the plasma treatment of raw materials used to prepare the construction mortars is characterized with high degree of efficiency and convenience of application.

scholarly journals EFINITION OF DEFORMATION OF FINE-GRAINED CONCRETE ON THE BASIS OF SULPHATE-RESISTANT PORTLAND CEMENT

Vestnik MGSU ◽  
2018 ◽  
pp. 1499-1508
Author(s):  
Ngo Xuan Hung ◽  
Tang Van Lam ◽  
Boris I. Bulgakov ◽  
Olga V. Aleksandrova ◽  
Oksana A. Larsen
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Setting Time ◽  
Relative Increase ◽  
Relative Deformation ◽  
Fine Aggregate ◽  
Distilled Water ◽  
Mean Values ◽  
Sand Mixture ◽  
Fine Grained

Introduction. The possibility of determining the relative deformations of fine-grained concretes based on sulfate-resistant cement was formulated by testing samples of gypsum-cement-sand mixture in distilled water in accordance with the requirements of the Vietnamese standard TCVN 6068:2004. Objective - to determine the deformations of fine-grained concrete because of sulfate-resistant Portland cement in accordance with the requirements of the TCVN 6068:2004 standard to assess its resistance to corrosion in an aggressive sulfate medium. Materials and methods. To obtain a gypsum-cement-sand mixture, a finely disintegrating binder was used, consisting of sulfate-resistant Portland cement of the type CEM I CC 42.5 N produced by the “Tam Diep” plant with the addition of natural gypsum produced by the company “Dinh Vu”. Quartz sand was used as fine aggregate. All raw materials used were native to Vietnam. Grinding fineness, normal cement density, setting time, the uniformity of the volume change and the activity of sulfate-resistant Portland cement were determined according to GOST 30744-2001; deformations of samples from gypsum-cement-sand mixtures - according to the Vietnamese standard TCVN 6068:2004. Results. Investigated the relative increase in the volume of samples of gypsum-cement-sand mixture based on sulfate-resistant Portland cement and natural gypsum as a result of their testing in distilled water according to the standard TCVN 6068:2004. Conclusions. Found that the average value of the relative deformation of the prism samples of concrete as a result of a 14-day test in distilled water was 0.037 %, which is within the acceptable value of 0.04 % in accordance with the requirements of the Vietnamese standard TCVN 6067:2004. Therefore, sulfate-resistant Portland cement type CEM I CC 42.5 N produced by the “Tam Diep” plant is a promising material as a binder for the preparation of corrosion-resistant concrete. The increase in the mean values of the relative deformations of the gypsum-cement-sand prism specimens after the 28-day and 60-day of testing, compared to the results of the 14-day test, can be explained by a slightly increased content of tricalcium aluminate in the studied cement.

INDUSTRIAL WESTE ACCOUNTING ON EXAMPLE ASH DUMPS

2021 ◽  
Vol 4 (4) ◽  
pp. 182-188
Author(s):  
T. S. BUDINA ◽  
◽  
N. Kh. KURBANOV ◽  
L. M. PROKOFIEVA ◽  
V. G. SHIYKO ◽  
...  
Keyword(s):  
Production Efficiency ◽  
Raw Materials ◽  
Accurate Determination ◽  
Accounting System ◽  
Secondary Material ◽  
Ash And Slag Waste ◽  
Sufficient Degree ◽  
Slag Waste ◽  
Financial Result

The article is devoted to the problems of accounting for industrial waste (technogenic deposits) on the example of ash and slag dumps. The influence of the organization of accounting for technogenic deposits on the indicators of cost, profit, and profitability of the enterprise, if these wastes are sold or used as secondary material, is studied. It is proved that the accounting system should accumulate and form such information that would allow with a sufficient degree of accuracy to determine the economic efficiency of the integrated use of raw materials, would aim at identifying reserves for increasing production efficiency. According to the authors, accounting under IFRS provides a more accurate assessment of ash and slag waste, which ultimately will allow the most accurate determination of the financial result from their further use.

scholarly journals AN EFFECTIVE WAY TO RECYCLE 3D PRINTING CONCRETE SCRAP

2021 ◽  
Vol 4 (2) ◽  
pp. 12-18
Author(s):  
D.A. Tolypin ◽  
N. Tolypina
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Portland Cement ◽  
Quartz Sand ◽  
Raw Materials ◽  
Electricity Consumption ◽  
Cement Matrix ◽  
Fine Aggregate ◽  
Fine Grained ◽  
Control Samples

the article proposes a rational method for processing 3D printing concrete scrap using vibration equipment, which allows obtaining a multicomponent building material with minimal electricity consumption. As a crite-rion for the degree of grinding of concrete scrap, it is proposed to use the specific surface area of the finely dispersed part of concrete scrap, which should correspond to 400-500 m2/kg. The possibility of reusing the resulting product instead of the traditional fine aggregate of quartz sand is shown. It was found that the con-crete scrap without the addition of Portland cement hardens, reaching up to 48% of the compressive strength of the control samples by 28 days. When 10% of the binder CEM I 42.5 N was added to the concrete scrap processing product, the compressive strength of fine-grained concrete increased by 106.6%, and 20% of Portland cement - by 112.2 %, compared to the strength of control samples of a similar composition on tra-ditional quartz sand after 28 days of hardening. It is noted that this is primarily due to the weak contact zone of quartz sand and the cement matrix of concrete. The use of the product of processing concrete scrap al-lows obtaining building composites based on it with the complete exclusion of natural raw materials

scholarly journals Preparation of Portland Cement with Gold Ore Tailings

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Wang ◽  
Geng Yao ◽  
Xiangnan Zhu ◽  
Junxiang Wang ◽  
Peng Wu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Raw Materials ◽  
Setting Time ◽  
Hydration Product ◽  
Difficult Problem ◽  
Initial Setting Time ◽  
Gold Ore ◽  
Curing Age

The disposal of gold ore tailings (GTs) has been a very difficult problem for a long time. Thus, this study explored a new approach to the management of GTs by preparing Portland cement. Physical properties, reaction mechanisms, and hydration product types of cement prepared with GTs (C-GTs) and ordinary Portland cement (C-SS) were compared. X-ray diffraction (XRD), thermogravimetric (TG), and scanning electron microscope energy-dispersive spectroscopy (SEM-EDS) analysis techniques were used to study the mineralogical phases of the clinker and raw materials, hydration product types, and microtopography. The consistency, setting time, flexural strength and compressive strength values of the cement samples (C-GTs and C-SS), and burnability of the raw materials were also studied. The burnability analysis indicated that GTs provided a higher reactivity. The XRD results showed that the clinker phases of the C-GTs were C3S, C2S, C3A, and C4AF. The XRD, TG, and SEM-EDS results showed that the hydration products were flaky calcium hydroxide, rod-shaped ettringite, and granular C-S-H gels. Its compressive strength and flexural strength were, respectively, 30.4 MPa and 6.1 MPa at the curing age of 3 days and 59.1 MPa and 9.8 MPa at the curing age of 28 days, which were slightly higher than those of the C-SS. Furthermore, the results showed that the consistency, initial setting time, and final setting time for the two kinds of cement were similar, which further suggested that GTs could be used to prepare Portland cement.

scholarly journals Special Concrete with Polymers

2016 ◽  
Vol 14 (11) ◽  
pp. 7-10
Author(s):  
Nicolae Angelescu ◽  
Ioana Ion ◽  
Darius Stanciu ◽  
José Barroso Aguiar ◽  
Elena Valentina Stoian ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Portland Cement ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Polymeric Materials ◽  
Polymer Concrete ◽  
Fine Aggregate ◽  
Concrete Mixtures ◽  
Experimental Works ◽  
Materials Used

Abstract The development of polymeric materials offers new perspectives of science and technology due to their outstanding properties. These properties are obtained either due to the effect of dispersion polymers and their polymerization either due to their intervention in structure formation. They were prepared epoxy resin polymer concrete, Portland cement, coarse and fine aggregate and to evaluate the influence of resin dosage on microstructures and density of such structures reinforced concrete mixtures. The paper detailing the raw materials used in experimental works and structural properties of concrete studied.

scholarly journals Analytical evaluation and systematization of technologies for extraction of rare metals from production waste

2021 ◽  
Vol 311 ◽  
pp. 09005
Author(s):  
L. Ya. Shubov ◽  
I. G. Doronkina ◽  
O. N. Borisova ◽  
L. M. Tyger ◽  
T. R. Lyubetskaya
Keyword(s):  
Permanent Magnets ◽  
Raw Materials ◽  
Liquid Waste ◽  
Acid Leaching ◽  
Production Waste ◽  
Rare Metals ◽  
Resource Saving ◽  
Alumina Production ◽  
Ash And Slag Waste ◽  
Slag Waste

The article is a message containing systematized information on resource-saving technologies as the basic for involving metal-containing secondary raw materials in the economic turnover. The set of independent technologies arranged in a certain sequence that solve the problems of resource saving allows us to compare the specific features and effectiveness of the use of each of them, the details and features of the processes. It is shown that the following can be the main sources of rare metals and REE: phosphogypsum (REE, Sr); ash and slag waste from TPPs, ash and slag waste (REE, Ti, Sc); metallurgical slags (Ge, Be, Se, Te, V); sulfuric acid dust (Se, Te); alumina production waste - red mud (Sc, REE); liquid waste from sulphate production of titanium dioxide (Sc, Ti); refinery dust bins (Se, Te); wastes from production of permanent magnets (Nd, Sm). It is noted that the technology uses beneficiation methods, acid leaching and ion-exchange concentration, biotechnology, electrolysis, heat treatment, a combination of different methods. To assess the quality of man-made raw materials and their suitability for complex processing and utilization, the article uses the methodology of analytical research of a set of patented technological solutions (technological samples were taken from real man-made deposits).

Ash-Slag Waste of the Coal-Fired Thermal Power Plant as a Resource for the Construction Industry

2021 ◽  
Vol 1038 ◽  
pp. 290-295
Author(s):  
Viktor Kolokhov ◽  
Lina Moroz ◽  
Andrey Romin ◽  
Volodymyr Kovregin
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Raw Materials ◽  
Thermal Power ◽  
Metallurgical Industry ◽  
Ash And Slag Waste ◽  
Technical Properties ◽  
Concrete Materials ◽  
Slag Waste ◽  
Wide Potential

The article presents a study of the physical and technical properties of ash and slag waste Coal Power Plant. The main problem when using ash-slag mixtures is the variability of the particle size distribution of the material. Determining the characteristics of slag stored in the dumps of thermal power plants will help to choose the separation methods of this material, to address the disposal and accumulation of industrial waste, to expand the scope of their application. The obtained research results of physical and technical properties of waste of the Coal TPP testify to wide potential in the further use in many branches of the industry. Possible applications include fillers for concrete, materials for sandblasting (abrasive material), raw materials for the metallurgical industry, additives for the manufacture of binders, etc.

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