The Structural Formation of Cement Stone Modified by a Solution of Superabsorbent Polymer

2022 ◽  
Vol 906 ◽  
pp. 59-67
Author(s):  
Alexandr Sergeevich Inozemtcev ◽  
Evgenij Korolev ◽  
Duong Thanh Qui
Keyword(s):  
Portland Cement ◽  
Structure Formation ◽  
Water Loss ◽  
Cement Hydration ◽  
Cement Stone ◽  
Layer By Layer ◽  
Superabsorbent Polymer ◽  
Hydration Products ◽  
Structural Formation ◽  
Strength And Durability

With the development of 3D technologies in construction, the development of formulations that are indifferent to the influence of the environment is in demand. Conditions of intense water loss from cement systems arise during the layer-by-layer printing process. This leads to a decrease in density, high shrinkage, and a decrease in the strength and durability of the composite. The use of superabsorbent polymer (SAP) solutions, in contrast to granules, will provide hardening Portland cement with a water supply for internal care of hydration processes. The aim of the work is to study the effect of SAP solution on the processes of structure formation of cement stone, hardening in unfavorable conditions. In this paper, the features of the structure formation of cement systems in the presence of SAP are established. It is shown that the use of polymer in an amount of no more than 1.5% by the weight of Portland cement provides the formation of a more perfect crystalline structure of the cement stone, which allows for an increase in the degree of cement hydration. When the amount of SAP is ≥ 1.5% by the weight of Portland cement, a decrease in the intensity of the maxima corresponding to hydration products is observed.

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

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.

Influence of Nanoscale Barium Hydrosilicates on Composition of Cement Stone

2016 ◽  
Vol 683 ◽  
pp. 90-94 ◽  
Author(s):  
Anna Nikolaevna Grishina ◽  
Evgeniy Valerjevich Korolev
Keyword(s):  
Composite Materials ◽  
Chemical Composition ◽  
Portland Cement ◽  
Cement Hydration ◽  
Experimental Investigations ◽  
Cement Stone ◽  
Hydration Products ◽  
Efficient Control ◽  
Calcium Hydrosilicates ◽  
Portland Cement Hydration

The development of new types of composite materials is an important aim for construction. Nanoscale admixtures allow efficient control of the composition and properties. Results of experimental investigations concerning effect of admixture of nanoscale barium hydrosilicates to the chemical composition of hydrated portland cement are discussed in the present work. It is shown that several key processes are taking place during nanomodification. Amount of portlandite in cement stone decreases, and there is also quantity growth of different calcium hydrosilicates CSH (I), CSH (II), riversideite and xonotlite. Influence of composition and storing time of barium hydrosilicates to the ratio of different portland cement hydration products is examined. It is found that admixture of barium hydrosilicates with gross formula BaO•26.47SiO2•nH2O stored for 28 days leads to both reduction of portlandite and accretion of hydrated phase.

scholarly journals Monitoring of Early and Late Age Hydration Products of Volcanic Ash Blended Cement Paste

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 9
Author(s):  
Joseph ◽  
Al-Bahar ◽  
Chakkamalayath ◽  
Al-Arbeed ◽  
Rasheed
Keyword(s):  
Portland Cement ◽  
Cement Paste ◽  
Volcanic Ash ◽  
Cement Hydration ◽  
Blended Cement ◽  
Sustainable Construction ◽  
Hydration Products ◽  
N2 Adsorption ◽  
Complete Replacement ◽  
Blended Cement Paste

One of the major concerns of concrete industries is to develop materials that consume less natural virgin resources and energy to make sustainable construction practices. Efforts have been made and even implemented to use the waste/by product materials such as fly ash, slag, silica fume, and natural pozzolana as a partial or complete replacement for Portland cement in concrete mixtures. The deterioration of concrete structures in the existing hot and cold climates of Gulf Cooperation Council countries, along with chloride and sulphate attack, demands the use of pozzolanic materials for concrete construction. Volcanic ash incorporated cement based concretes are known for its better performance in terms of strength and durability in harsh marine environments. Understanding the cement hydration process and characterizing the hydration products in microstructural level is a complex and interdependent process that allows one to design complex mix proportions to produce sustainable concrete materials. In this paper, the early and late age hydration behavior along with micro- and pore structure of cement paste samples prepared with locally available ordinary Portland cement (OPC) and volcanic ash (VA) obtained from Saudi Arabia was monitored using X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TGA) and N2-Adsorption analysis. The hydration progress of cement paste samples with different combinations of OPC and VA (0%, 15%, 25%, and 35%) at a w/c ratio of 0.45 after 14, 28, and 90 days were discussed. The qualitative XRD and SEM of cement paste samples showed no new phases were formed during the course of hydration. The disappearance of portlandite with increase in VA content was due to both pozzolanic effect and dilution effect. This was further confirmed quantitatively by the TGA observations that the samples with VA contain less Ca(OH)2 compared to the control specimens. N2 adsorption experiments after 90 days of curing showed larger hysteresis as the VA content increases. The studies show that the incorporation of volcanic ash certainly contributes to the generation of C-S-H and hence the cement hydration progress, especially in the later ages through pozzolanic reactions. A 15–25 % volcanic ash blended cement paste samples showed compact and denser morphological features, which will be highly detrimental for the durability performances.

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

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.

scholarly journals PECULIAR PROPERTIES OF STRUCTURAL FORMATION OF CEMENT COMPOSITES IN THE PRESENCE OF FUELEROID TYPE CARBON NANOPARTICLES

Vestnik MGSU ◽  
2017 ◽  
pp. 718-723 ◽  
Author(s):  
Yuriy Vladimirovich Pukharenko ◽  
Dmitriy Igorevich Ryzhov ◽  
Vadim Dmitrievich Staroverov
Keyword(s):  
Carbon Nanoparticles ◽  
Microstructural Analysis ◽  
Crystalline Hydrate ◽  
Structure Characteristic ◽  
Cement Stone ◽  
Cement Composites ◽  
Structural Formation ◽  
Strength And Durability ◽  
Heterogeneous Interactions ◽  
Rigid Matrix

The paper deals with the application of fulleroid carbon nanoparticles (FCN) for the cement com-posites modification. In particular, the thermokinetic analysis was performed to assess the change in the rate and completeness of the cement hydration when the nanomodifier was introduced into it. The study of exothermic heterogeneous interactions and thermal effects in the binder - water - nanomodifier system allows one to estimate the hydration rate and depth and to assess the degree of nanomodifier’s influence. The conducted studies revealed the increase in the hydration temperature when carbon nanoparticles are introduced into the cement dough, while the induction period is prolonged, that indicates a more complete course of the reactions. It is confirmed by the results of qualitative X-ray structural analysis. The dynamics of decrease in calcium silicate peaks characterizes the completeness of hydration and binding of portlandite, that explains the increase in the modified cement stone strength. Microstructural analysis allows to detect the structure characteristic of control samples with a large number of large chaotically located crystals, the bulk of which is formed on the first day of solidification. Under the same conditions, the modification of the cement stone contributes to the creation of the more dense spatial structure consisting of small crystalline hydrate formations. All that process positively influences the formation of the rigid matrix with a smaller number of pores, which determines the in-crease in strength and durability of cement stone and concrete on its basis.

scholarly journals MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL

2017 ◽  
Vol 2 (3) ◽  
pp. 9-18 ◽  
Author(s):  
Золотых ◽  
Sergey Zolotykh ◽  
Сумской ◽  
Dmitriy Sumskoy ◽  
Загороднюк ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Portland Cement ◽  
Mechanical Activation ◽  
Cement Stone ◽  
Mineral Filler ◽  
Hydration Products ◽  
Dense Structure ◽  
Additional Support ◽  
Effective Use

Zagorodnuk L.H., Sumy D.A., Golden S.V., Kaneva E.V. MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL By electron microscopy to study the microstructure of the cement stone made from Portland cement and activated binders of the compositions in the vortex jet mill. It was found that the open pores of the cement and cementitious compositions prepared using perlite fillers, always filled with tumors, at different stages of collective growth. The microstructure of cementitious compositions has a dense structure by rationally selected composition, effective use of mineral filler - perlite waste, creating additional support for the formation of the internal microstructure of the composite, mechanical activation raw mixture, allowing to obtain composites with desired properties.

Improvement of Wood-Cement Composition Properties with Microsilica Additive

2020 ◽  
Vol 992 ◽  
pp. 162-167
Author(s):  
E.Yu. Gornostaeva ◽  
N.P. Lukuttsova ◽  
D.I. Dryazgov
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Silicon Dioxide ◽  
Cement Hydration ◽  
Cement Stone ◽  
Hydration Products ◽  
Maximum Increase ◽  
Calcium Hydrosilicates ◽  
Calcium Silicates ◽  
Composition Properties

The properties and microstructure of wood-cement compositions (WCC) with microsilica (MS) additive for the manufacture of small-pieces wall products are studied. The extreme dependences of mean density, thermal conductivity and compressive strength on the content of microsilica additive are established. The mechanism of microsilica effect on wood-cement compositions is offered. Two interrelated factors (chemical and physical) could be distinguished at that. The first factor includes mainly the interaction of silicon dioxide with lime having released during hydration of calcium silicates, i.e. pozzolatic process. The second factor lies in the compaction of wood-cement compositions and the cement stone structure by means of cement hydration products and silica particles. It is established that introducing 20% of microsilica in the composition results in the maximum increase in ultimate compression strength (3 times). It can be explained not only by forming calcium hydrosilicates, uniformly and densely covering the wood aggregate, but by compacting effect of spherical microsilica inclusions, filling the space between the new cement stone formations and wood aggregate.

Improving the Efficiency of Slag Portland Cement by Reducing Shrinkage Deformations

2020 ◽  
Vol 992 ◽  
pp. 104-110
Author(s):  
Svetlana V. Samchenko ◽  
D.A. Zorin
Keyword(s):  
Portland Cement ◽  
Compression Strength ◽  
Cement Hydration ◽  
Early Stage ◽  
Cement Clinker ◽  
Cement Stone ◽  
Slag Cement ◽  
Portland Cement Clinker ◽  
Granulated Slag ◽  
Portland Slag Cement

The influence of the artificial additive introduced at the joint grinding of granulated slag, Portland cement clinker and gypsum on the Portland slag cement hydration, its compression strength at an early stage and shrinkage deformation is investigated. It was found that in the presence of sulfoferrite clinker there is an amorphization of cement stone structure with formation of stone with high density and strength in early setting. The open porosity of the hardened paste is reduced by 13 – 15 % in comparison with plain Portland slag cement. The samples strength increases by 1.55 - 1.78 times at grade stage, by 15.5 - 19.4 % in bending and by 6.4 - 11.2 % in compression.

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

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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