Investigation of the Effect of Combined Binder Based on Portland Cement and Lime on the Properties of Non-Autoclave Silicate Materials Modified with Synthetic Crystalline Filler

2021 ◽  
Vol 1043 ◽  
pp. 127-132
Author(s):  
Aleksandr Volodchenko
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Raw Materials ◽  
Mineral Formation ◽  
Hardening Process ◽  
High Temperature And Pressure ◽  
Reduced Parameters ◽  
Temperature And Pressure ◽  
Clay Rocks ◽  
Silicate Materials

Among the wide variety of currently used wall building materials and products, it is possible to single out the autoclave-hardened silicate products. To obtain silicate materials of autoclave hardening, lime-silica binders are mainly used. The hardening process of such a binder is carried out in an environment of water vapor at high temperature and pressure. It is relevant to use a certain type of silicate materials in the technology with raw materials that provide hardening with reduced parameters of hydrothermal synthesis, which will make it possible to obtain wall silicate materials in non-autoclave conditions. This can be done through the use of clay rocks of the mineral formation unfinished stage. In the course of the research, the effect of a combined binder based on Portland cement and lime on the properties of non-autoclave silicate materials modified with a synthetic crystalline filler was studied. It has been established that the addition of a synthetic crystalline filler represented by artificial calcium hydro-silicates makes it possible to increase the presence of a crystalline phase formed due to the clinker minerals hydration in the early stages of hardening, and, as a consequence, to increase the operational properties of the resulting composites. The addition of lime to the raw mixture will additionally compensate for the lack of calcium ions during the entire hardening process of non-autoclave silicate composites based on aluminosilicate raw materials and Portland cement.

scholarly journals WALL SILICATE MATERIALS OF NON-AUTOCLAVE HARDENING WITH THE USE OF SILICA RAW MATERIALS AND ALUMINOSILICATE BINDING BASED ON NON-CONVENTIONAL CLAY ROCKS

2019 ◽  
pp. 25-34
Author(s):  
А. Володченко ◽  
A. Volodchenko
Keyword(s):  
Building Materials ◽  
Raw Materials ◽  
High Energy ◽  
Structural Features ◽  
Average Density ◽  
High Pressure And Temperature ◽  
Production Technologies ◽  
Clay Rocks ◽  
Microstructure Of The Material ◽  
Silicate Materials

Among the used building materials, structural autoclave silicate products occupy one of the leading places. The traditional technology of silicate materials uses autoclave processing of products, the main disadvantage of which is the high energy intensity. In order to create non-autoclave silicate composites based on conventional siliceous raw materials, it is proposed to use a special aluminosilicate binder based on clay rocks of the incomplete stage of mineral formation of a certain genesis and quicklime. The strength of silicate materials is growing as a result of the neoplasm process. They are synthesized in the chemical reaction of quicklime with components of clay rocks when using high pressure and temperature modes in an autoclave, and when steaming with temperatures up to 100 °C. The high specific surface of the aluminosilicate binder provides an increase in the packing density of the material. Due to the structural features of the CaO-SiO2 (Al2O3)-H2O system based on unconventional clay rocks, the process of formation of the microstructure of the material, which continues and after hydrothermal treatment of the products, gives the material hydraulic properties. The proposed binders and their production technologies can be implemented in small and medium-sized businesses, which will allow to obtain competitive non-autoclave silicate materials with a compressive strength of up to 25 MPa and an average density of 1850 kg/m3.

scholarly journals INFLUENCE OF ARTIFICIAL CALCIUM HYDROSILICATES ON THE HARDENING PROCESSES AND PROPERTIES OF NON-AUTOCLAVE SILICATE MATERIALS BASED ON UNCONVENTIONAL ALUMINOSILICATE RAW MATERIALS

2020 ◽  
Vol 3 (2) ◽  
pp. 19-28 ◽  
Author(s):  
A. Volodchenko
Keyword(s):  
Structure Formation ◽  
Building Materials ◽  
Raw Materials ◽  
Strength Increase ◽  
Isothermal Exposure ◽  
Moisture Treatment ◽  
Calcium Hydrosilicates ◽  
Clay Rocks ◽  
Heat And Moisture ◽  
Silicate Materials

one of the possible ways to improve the properties of building materials is to modify the processes of structure formation, which can be realized through the use of crystalline primers. In this regard, it is urgent to study the effect of artificial calcium hydrosilicates on hardening processes, as well as the properties of non-autoclave silicate materials based on non-traditional aluminosilicate raw materials. Studies have shown that the addition of artificial calcium hydrosilicates (CSH) in an amount of 1-1.5 wt. %, when the content in the mixture of CaO is less than 10 wt. %, effectively increases the strength parameters of products at all stages of heat and moisture treatment from 8 to 16%. The most intense increase in strength is observed during the heat-moisture treatment (TBO) from 3 to 6 hours and is at least 13%, while in samples without the addition of artificial calcium hydrosilicates, the strength increase is 6%. The addition of artificial calcium hydrosilicates intensifies the processes of structure formation, which ensures an increase in crystalline matter, and, due to the fibrous structure, acts as a fiber, which contributes to the nano-reinforcement of the cementing substance formed from neoplasms in the CaO-SiO2(Al2O3)-H2O system based on clay rocks and calcium oxide. Due to the accelerated set of strength, it is possible to reduce the duration of isothermal exposure while maintaining the necessary performance characteristics.

scholarly journals NON-AUTOCLAVE SILICATE COMPOSITES USING NON-TRADITIONAL RAW MATERIALS AND CRYSTAL FILLER

2020 ◽  
pp. 8-17
Author(s):  
A. Volodchenko
Keyword(s):  
Structure Formation ◽  
Raw Materials ◽  
Raw Material ◽  
Formation Processes ◽  
Product Density ◽  
Hardening Process ◽  
Calcium Hydrosilicates ◽  
Synthetic Crystal ◽  
Silicate Materials ◽  
Crystalline Growth

In the construction of buildings and structures, many wall materials are used, including silicate products of various functional purposes. In traditional production technology of such materials, the hardening process occurs due to the formation of a crystal structure in the CaO-SiO2-H2O system. There are various ways to modify the crystalline growth of the cementing substance, one of which is the use of various kinds of crystal seedings, in particular the use of natural and synthetic calcium hydrosilicates. The purpose of the experiments is to study the possibility of improving the performance properties of non-autoclave silicate composites by modifying the structure formation in the "lime-non-traditional aluminosilicate raw materials" system, which consists in the crystal-chemical regulation of the structure formation processes with a synthetic crystal filler CaO-SiO2-H2O (C-S-H). The use of synthetic crystalline filler C-S-H synthesized by hydrothermal synthesis in an autoclave at a pressure of 1 MPa and a temperature of 175 °C from a mixture of Ca(OH)2 and crystalline silica in a ratio different C/S=1 in the technology of non-autoclave silicate materials on the basis of alternative aluminium raw material allows to increase the operational indicators resulting products to 18 % or more. The optimal content of CaO and crystal filler C-S-H at which the maximum strength characteristics are provided is 8 % and 2.5 %, respectively, which allows to develop optimal compositions of raw materials for the technology of producing high-density non-autoclave silicate materials based on non-traditional aluminosilicate raw materials with a compressive strength of at least 20 MPa and more, with an average product density of no more than 2000 kg /m3.

On the Issue of Reducing the Energy Intensity of the Silicate Composites Production with the Unconventional Aluminosilicate Raw Materials Use

2019 ◽  
Vol 974 ◽  
pp. 20-25 ◽  
Author(s):  
A.A. Volodchenko ◽  
Valery S. Lesovik ◽  
L.K. Zagorodnjuk ◽  
E.S. Glagolev
Keyword(s):  
Energy Saving ◽  
Building Materials ◽  
Energy Intensity ◽  
High Pressures ◽  
Raw Materials ◽  
High Reactivity ◽  
Raw Material ◽  
Green Technologies ◽  
Materials Used ◽  
Clay Rocks

The energy intensity of production of the most common wall materials in Russia is significantly higher than their foreign counterparts. The urgent task is to reduce the energy intensity of the production of building materials, to develop and introduce energy-saving nature-like technologies for the production of building materials, which corresponds to modern trends in the development of "green" technologies. It is possible to reduce the energy intensity of the production of silicate materials due to the transition from traditional raw materials to the use of unconventional aluminosilicate raw materials of various genesis, in particular, clay rocks of the unfinished stage of mineral formation. In the course of the research, the possibility of the synthesis of the new growth in the system “aluminosilicate raw material – calcium hydroxide – water” under the conditions of hydrothermal treatment was shown. Due to the high reactivity of the raw materials used, under the conditions of hydrothermal processing, the synthesis of tumors occurs not only at high pressures and temperatures, but also at temperatures up to 100 °C. This will allow to obtain efficient hollow-walled wall building materials using energy-saving technology.

Utilization of Hydrolysis Lignin in Compositions Soil-Cements

2019 ◽  
Vol 23 (11) ◽  
pp. 32-37
Author(s):  
N.A. Konovalova ◽  
O.N. Dabizha ◽  
P.P. Pankov ◽  
E.A. Rush
Keyword(s):  
Portland Cement ◽  
Model Experiment ◽  
Building Materials ◽  
Raw Materials ◽  
Hydrolysis Lignin ◽  
X Ray ◽  
Road Building ◽  
The Road ◽  
Hydrolyzed Lignin ◽  
Scanning Electron

The article investigated the compositions of road-building materials containing screenings of rock crushing, Portland cement, hydrolyzed lignin, modified by the stabilizing additive “Element”. The road-building compositions containing screenings of rock crushing, Portland cement, hydrolyzed lignin modified with the stabilizing additive "Element" were investigated. The optimal content of raw materials has been established, which allows to obtain soil-cements with a strength mark of at least M 60 - M 75. Using a model experiment, it was shown that the stabilizing additive “Element” is active and can interact with each of component of the raw materials. Using the methods of scanning electron microscopy, infrared spectroscopy, X-ray phase analysis, it has been experimentally shown that the processes of hydration, carbonization and increasing the connectivity of orthosilicate anions play a significant role in the structure formation of soil-cements.

Synthesis of Modifiers in the System Cao-Sio2-H2O and their Influence on the Non-Autoclave Silicate Materials’ Properties Using Aluminosilicate Binder

2020 ◽  
Vol 1011 ◽  
pp. 144-150
Author(s):  
Aleksandr Volodchenko
Keyword(s):  
Building Materials ◽  
Water Resistance ◽  
Pore Space ◽  
Crystalline Substance ◽  
Materials Properties ◽  
Clay Rocks ◽  
Increased Strength ◽  
Cementing Material ◽  
Crystallization Degree ◽  
Silicate Materials

Improving the hydration hardening building materials’ operational properties is possible due to the stable macro-, micro-and nanostructures’ creation by the cementing material crystalline aggregate directed modification, which can be achieved through the use of various additives acting as crystallization centers. In the course of the studies, the synthesized modifier effect nature represented by the system was revealed CaO-SiO2-H2O (CSH) on the properties of non-autoclave silicate materials using aluminosilicate binder of various compositions. It has been established that the use of an aluminosilicate binder together with the addition of a CSH modifier increases the presence of a crystalline phase at all stages of hardening, as well as intensifies the synthesis of low-basic calcium hydro silicates with a higher crystallization degree in the system CaO-SiO2(Al2O3)-H2O represented by lime and clay rocks. This contributes to the micro-reinforced crystalline framework formation of the neoplasms with increased strength. Due to this, the pore space decreases and the amount of synthesized crystalline substance increases, which helps to increase the water resistance of the samples in all compositions. The samples using an aluminosilicate binder and the addition of a CSH modifier achieve maximum strength with a CaO content of not more than 10 wt. % The optimal CSH modifier addition is up to 1.5 wt. %, with 7 wt. %, CaO content in a mixture increase in strength is up to 6%.

Assessment of Raw Mineral Waste as Building Materials in Developing Countries

2018 ◽  
Vol 40 ◽  
pp. 30-46
Author(s):  
Njarazo Rakotondrabezaharinoro ◽  
Moutari Ado ◽  
Willy Hermann Juimo Tchamdjou
Keyword(s):  
Mechanical Properties ◽  
Developing Countries ◽  
Portland Cement ◽  
Building Materials ◽  
Raw Materials ◽  
Activity Index ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Replacement ◽  
Mineral Waste

In many developing country’s mining exploitations are the main activities sources, and its exploitation is generating many mining wastes and environmental impacts. In order to use these waste, an innovative powder and aggregate were designed, aimed at providing alternative materials by cementitious supplementary materials and sand in Portland cement mortars. This paper investigates the use of raw mineral waste from some developing countries, namely Granite Residue (GR), from Niger, Mining Tailings (MT), from Madagascar, and red Volcanic Scoria (VS), from Cameroon as building materials. These raw materials were valorized as supplementary cementitious materials (GR powder, MS powder and VS powder) and as sand (GR sand and VS sand). GR sand and VS sand were used by 100% replacement of standard sand and GR powder, MS powder and VS powder were used by 5, 15, 25, or/and 35% cement replacement. Physical properties and mechanical properties of raw materials used and mortars obtained were investigated. The effects of these raw materials on properties of mortar mixes were studied and reported. Results show that, with sand from raw mineral waste materials, the compressive and flexural strengths of the produced mortar represented up than 70% and up than 85% respectively in comparison with mortar produce with siliceous standard sand. The reduction of strength of mortar with raw powder as ordinary Portland cement replacement is generally smaller than replacement ratio. Activity index of each raw powder is about 75% for ratio replacement of 5, 15 and 25%. Particle size distribution of raw powder and sand have an influence on the workability and mechanical properties of mortars. In conclusion, the use of raw mineral waste as a raw powder or as sand for mortar production presents an economical and environmental advantage for developing countries where mining exploitations are abundant.

scholarly journals Innovative Technologies for the Production of Ceramic Building Materials from Waste of Natural (Exogenous) Processes

2021 ◽  
Vol 906 (1) ◽  
pp. 012046
Author(s):  
Elena Shapakidze ◽  
Izolda Kamushadze ◽  
Lamara Gabunia ◽  
Ioseb Gejadze ◽  
Rajden Skhxvitaridze ◽  
...  
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Raw Materials ◽  
Low Cost ◽  
High Energy ◽  
Raw Material ◽  
Clay Shale ◽  
Innovative Technologies ◽  
Ceramic Building ◽  
Main Component

Abstract The main material for the modern construction business is cement/concrete, the production of which is associated with high energy and material costs and, most importantly, high CO2 emissions into the atmosphere. Based on this, the development of technologies for new energy-efficient building materials - substitutes for Portland cement is of great importance. One of the ways to solve this problem could be the wider use of ceramic building materials, the production of which requires less energy and is not associated with high CO2 emissions compared to the production of Portland cement. The subject of this article is the development of innovative technologies for the production of ceramic building materials in Georgia (ordinary building bricks and clinker bricks) by using unconventional raw material - clay shale aluvium which is a waste of natural (exogenous) processes. As the main component of the ceramic mass, we used clay shale aluvium from the Duruji river bed near the town of Kvareli, which made it possible to reduce the firing temperature and improve the quality of the finished product. X-ray phase, petrographic and electronic microscopic studies have shown that ceramic products, both building and clinker bricks, made with the use of Kvareli shale, under the same firing conditions, have been obtained with a denser structure ensuring higher physical and mechanical features as compared to clay Metekhi, which is currently used by the brick factory in Georgia. The use of shale accumulated in the region of Kvareli in various areas of the economy (including production of ceramic building materials) will make it possible to clear the adjacent territory from risky deposits of natural alluvium, which threatens to flood the city and provide companies engaged in production of ceramic building materials with low-cost and environmentally friendly raw materials.

Effective Non-Autoclave Silicate Blocks of Casting Molding Process Based on Unconventional Aluminosilicate Raw Materials

2019 ◽  
Vol 974 ◽  
pp. 55-60
Author(s):  
A.A. Volodchenko ◽  
V.M. Vorontsov ◽  
I.A. Cherepanova
Keyword(s):  
Composite Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Material Composition ◽  
Raw Material ◽  
Mineral Formation ◽  
Molding Process ◽  
Intensive Research ◽  
Problems And Solutions ◽  
Clay Rocks

Currently, intensive research is being conducted, both in Russia and abroad, to study the general principles, problems and solutions in the development of effective composite materials for construction purposes. It is shown that it is possible to use unconventional aluminosilicate raw materials represented by clay rocks of the incomplete stage of mineral formation as a raw material for the production of non-autoclaved silicate blocks of casting molding process. These raw materials due to the peculiarities of its material composition actively interact with the cementing component in non-autoclave conditions, with the formation of cementing compounds of the CaO-SiO2-Al2O3- H2O system, which provides high physical and mechanical performance of non-autoclave silicate products.

Investigation on the Creep property of Theoretical Composition Magnesia Alumina Spinel Bricks

2013 ◽  
Vol 690-693 ◽  
pp. 654-657
Author(s):  
Shan Shan Hong ◽  
Yong Li
Keyword(s):  
High Temperature ◽  
Creep Rate ◽  
Raw Materials ◽  
Creep Property ◽  
High Temperature Creep ◽  
Creep Experiment ◽  
Compact Structure ◽  
High Temperature And Pressure ◽  
Long Time ◽  
Temperature And Pressure

Using alumina-rich MgAl2O4 spinel AR78 and 97 fused magnesite as raw materials, brine as the binder, magnesia alumina spinel bricks close to theoretical composition have been prepared. Then the high temperature creep experiments are carried on. The creep property is analyzed by microstructure and creep curve. The results show that: (1) The magnesia alumina spinel bricks close to theoretical composition prepared have well sintering performance and compact structure.(2) The specimen 1# has the best creep property, of which the final creep rate was -1.45% after creep experiment for 50h. (3) Under high temperature and pressure for a long time in creep experiment, the internal of spinel is further sintered, the pores of the specimens are rearranged.

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