CEMENT STONE STRUCTURE COMPACTION WITH COMPOSITE BINDER

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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The Increase of Hydration Activity of Portland Cement by Additives of Crystalline Hydrates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.974.195 ◽

2019 ◽

Vol 974 ◽

pp. 195-200

Author(s):

Yury R. Krivoborodov ◽

Svetlana V. Samchenko

Keyword(s):

Phase Composition ◽

Portland Cement ◽

Cement Hydration ◽

Bound Water ◽

Cement Stone ◽

Pulsation Apparatus ◽

Rotary Pulsation Apparatus ◽

Calcium Hydrosilicates ◽

Crystalline Hydrates

The article presents the results of a study of the effect of synthesized microdisperse additives of crystalline hydrates based on calcium sulfoaluminates on the properties of cement stone. The effectiveness of the use of a rotary pulsation apparatus (RPA) to obtain microdispersed additives is identified. The possibility of accelerating the hardening of cement stone by entering microdispersed additives into its composition is shown. It has been established that in the presence of microdispersed additives of crystalline hydrates in the cement stone, the phase composition of hydrate tumors changes, the amount of calcium hydrosilicates and ettringite increases, the porosity decreases and the strength of the cement stone increases. This provision is confirmed by the increase in the degree of cement hydration, the amount of bound water in all periods of hardening of the stone. It is proposed to use microdisperse additives, which play the role of primers for the crystallization of ettringite and calcium hydrosilicates, to increase the strength of cement stone in the early stages of hardening.

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Development of Fibre-Cement Composites with Self-Cleaning and de-NOx Ability

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1124.123 ◽

2015 ◽

Vol 1124 ◽

pp. 123-129

Author(s):

Martin Bohac ◽

René Čechmánek ◽

Theodor Staněk

Keyword(s):

Portland Cement ◽

Cement Composites ◽

Composite Binder ◽

Fibre Cement ◽

Thin Walled ◽

Self Cleaning ◽

White Portland Cement

Paper deals with development of face architectural fibre-cement composites based on white Portland cement with addition of photoactive TiO2. Tests were carried on composite binder and then on the composites. The role of TiO2 on performance of materials was monitored. Selected composites were tested on self-cleaning ability, de-NOx activity and resistance to weathering in outdoor conditions. Two series of thin-walled products based on developed composites were prepared with self-cleaning ability and de-NOx activity.

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Nano-level management of calcium silicate-hydrate nanoparticles structure formation during portland cement hydration process

MATEC Web of Conferences ◽

10.1051/matecconf/201819604012 ◽

2018 ◽

Vol 196 ◽

pp. 04012

Author(s):

Alexander Guryanov ◽

Vyacheslav Kozlov ◽

Yulia Sidorenko

Keyword(s):

Portland Cement ◽

Structure Formation ◽

Building Materials ◽

Cement Hydration ◽

Structural Parameters ◽

Control Process ◽

Hydration Process ◽

Cement Stone ◽

Carbonate Sludge ◽

Portland Cement Hydration

Cement-containing building materials durability depends both on the original clinker composition and on the structure of hydrated portland cement compositions on micro and nanoscales. To calculate structural parameters of silicate-hydrate calcium nanoparticles during portland cement hydration process, the researchers applied the method of small-angle neutron scattering which included distribution of nanoparticles in size, medium nanoparticles radius, fractal dimension. Modifying nanoparticles blending with portland cement composition affects structural parameters of silicate-hydrate calcium nanoparticles. The authors used complex modifying nanoparticles in this study. Nanoparticle composition included a component that served as a filler and a chemically active component that was used as a modifier. The first component was a mixture of alpha oxide aluminum, gamma oxide aluminum and carbonate sludge. The second component presented a mixture of alumoalkaline sludge with alumocalcite sludge. These sludges were of technogenic origin. The research showed that application of complex nanoagents made it possible to control process of silicate-hydrate calcium nanoparticles structure formation, and, as the result, to influence durability of cement stone.

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INFLUENCE OF THE SCOPE ADDITION ON THE STRUCTURE FORMATION OF THE CEMENT STONE BY THE METHOD OF QUANTITATIVE X-RAY PHASE ANALYSIS

The Russian Automobile and Highway Industry Journal ◽

10.26518/2071-7296-2019-4-504-518 ◽

2019 ◽

Vol 16 (4) ◽

pp. 504-518

Author(s):

I. L. Chulkova ◽

I. A. Selivanov ◽

V. D. Galdina

Keyword(s):

Portland Cement ◽

Structure Formation ◽

Phase Analysis ◽

Mineral Composition ◽

Large Scale ◽

Building Materials ◽

Cement Matrix ◽

Cement Stone ◽

X Ray ◽

Mineral Compositions

Introduction. The processes of structure formation of cement compositions and the development of effective technologies of building materials is an urgent task for building material science. The use of large-scale man-made product of pulp and paper enterprises – osprey as a fibrous filler in organic and mineral compositions is the successful decision of the problem. The paper analyzes the ways of using osprey in the building materials’ production. The aim of the research is to study the osprey influence on the processes of structure formation of cement stone by quantitative x-ray phase analysis.Materials and methods. The organic and mineral compositions were obtained on the basis of portland cement and osprey. The authors studied the compositions’ phase of osprey, portland cement and the processes of cement stone structure formation in organ and mineral compositions by quantitative x-ray phase analysis.Results. The authors determined the compositions’ phase of mineral impurities of osprey, cellulose, cement, cement stone, organic and mineral compositions and two compositions containing 25 and 75% by weight.Discussion and conclusions. The osprey application as a filler in the organic and mineral composition causes inhibition of processes of cement hydration. The presence of osprey in the hardening organic and mineral composition leads to a change in the composition and structure of the cement stone in comparison with the phase composition of the cement stone without additives. The result of these changes is a significant increase in the amount of calcite, waterite and a significant decrease in the amount of portland. The authors establish that the effective joint work of the reinforcing component of the osprey with the cement matrix is possible with a limited amount of osprey in organic and mineral compositions.

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Structure Formation Features of Non-Autoclaved Gas Concrete Matrix on the Basis of Composite Binders with Various Mineral Additives

Materials Science Forum ◽

10.4028/www.scientific.net/msf.974.249 ◽

2019 ◽

Vol 974 ◽

pp. 249-254

Author(s):

Michail V. Absimetov ◽

Mikhail Yurievich Elistratkin ◽

Marina S. Ageeva

Keyword(s):

Structure Formation ◽

Mutual Influence ◽

Strength Properties ◽

Mass Concrete ◽

Composite Binder ◽

Viscosity Change ◽

Molding Compound ◽

Scale Levels ◽

Good Potential ◽

Cellular Concrete

One of the effective ways to reduce the material consumption of structures, to save all types of resources due to this, is the transition to porous constructional materials instead of traditional dense materials. In this regard, non-autoclaved gas concrete is of great interest. This material has a high manufacturability and has a good potential for improving the strength properties due to the replacement of traditional portland cement by special composite binders. Available publications confirm the effectiveness and prospects of this direction. An important disadvantage of such works is the fact that the binder indicators and the final cellular concrete characteristics are considered mainly independently. In our opinion, it is more correct to consider at least two structure-forming processes proceeding in parallel and sequentially at different scale levels. Micro level is a stone structure formation based on the composite binder; macro-level is a gas porization of cellular mass concrete. These processes have a great mutual influence on each other, and therefore this article attempts to observe the gassing products effect on the stone hardening based on composite binders, as well as the composite binder makeup on the viscosity change of the molding compound, as an important condition for the formation of high-quality less defective pore structure of cellular concrete.

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A mechanism of Portland cement hardening in the presence of finely grained glass powder

Chemistry & Chemical Technology ◽

10.23939/chcht01.03.179 ◽

2007 ◽

Vol 1 (3) ◽

pp. 179-184

Author(s):

Victor Shevchenko ◽

◽

Wojciech Swierad ◽

Keyword(s):

Portland Cement ◽

Structure Formation ◽

Building Materials ◽

Glass Powder ◽

Cement Stone ◽

Developed Surface ◽

Glass Wastes ◽

Chemical Influence

The glass wastes as a cullet are widely used for the production of building materials mainly as inert aggregate. However finely grained glass powder has the very developed surface, so can not be passive toward cement solutions, what was confirmed in practice. In literature data there is no information about chemical influence of finely grained glass on the process of hardening, especially in an early pre-induction hydration period, which substantially causes the structure formation of cement stone and its properties.

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Effect of nanoscale additive based on CaO—SiO2 system on strength properties of Portland cement stone

Chemical Engineering ◽

10.31044/1684-5811-2020-21-7-309-316 ◽

2020 ◽

Vol 21 (7) ◽

pp. 309-316

Author(s):

A. I. Verenitsin ◽

◽

S. A. Kirillova ◽

V. I. Almjashev ◽

◽

...

Keyword(s):

Portland Cement ◽

Strength Properties ◽

Cement Stone ◽

Sio2 System

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ROLE OF GRANULOMETRY OF MIXED BINDERS IN FORMATION OF THEIR MICROSTRUCTURE AND STRENGTH

Bulletin of Belgorod State Technological University named after V G Shukhov ◽

10.34031/2071-7318-2021-6-7-33-43 ◽

2021 ◽

Vol 6 (7) ◽

pp. 33-43

Author(s):

L. Zagorodnyuk ◽

D.S. Mahortov ◽

V. Ryzhikh ◽

D. Sumskoy ◽

M. Dayronas

Keyword(s):

Portland Cement ◽

Volcanic Ash ◽

Pore Space ◽

Ash Content ◽

Cement Stone ◽

Hydration Products ◽

Mechanical Mixing ◽

Mineral Fillers ◽

Active Interaction

A complex system is formed when grinding Portland cement and various mineral fillers. It consists of grains of various sizes with a predominance of a highly dispersed phase. The work investigates the effect of mixed binders prepared on the basis of Portland cement and volcanic ash at various dosages. The analysis of volcanic ash particles is carried out. It is found that the presence of the smallest fractions in the range from 0.3 to 0.07 microns predicts active interaction in the system and the filling of the pore space with hydration products. It has been established that mixed binders obtained by mechanical mixing (without grinding) with a content of 10% volcanic ash have a strength 13% higher than no addition cement. Mixed binders activated by milling in a vibration mill with a volcanic ash content of 10% are characterized by an increase in compressive strength by 22%, which saves Portland cement by up to 10%. Mixed binders with a volcanic ash content of 20% correspond to the strength of cement free. The results obtained indicate the effectiveness and feasibility of using volcanic ash as a mineral component of mixed binders. The microstructure of a cement stone sample from an activated mixed binder is highly homogeneous, dense intergrown plates of a secondary hydrosilicate structure are clearly visible in the sample cleavage, and crystalline products of pozzolanic reactions between ash particles and cement hydration products are formed on the surfaces of secondary hydrosilicate structures. The purpose of this article is to study the role of granulometry of mixed binders in the formation of their microstructure and strength.

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Regulation of the Properties of Construction Composites Depending on the Material Composition

Materials Science Forum ◽

10.4028/www.scientific.net/msf.989.306 ◽

2020 ◽

Vol 989 ◽

pp. 306-311

Author(s):

Ekaterina S. Gerasimova ◽

Kamila Masharipova

Keyword(s):

Portland Cement ◽

Structure Formation ◽

Material Composition ◽

Cement Stone

This paper is devoted to research of directional regulation possibility of the properties of a composite based on the Portland cement by using limestone waste. It is shown that the introduction of limestone waste contributes to changing the nature of crystallization and structure formation of cement stone. With the introduction of limestone waste, in the amount of 15 % by weight of cement, it is possible to obtain the compositions of the class not less than B25-B35.

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