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

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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A Study of the Potential Use of Red Mud to Obtain Compositions Based on Portland Cement

KnE Materials Science ◽

10.18502/kms.v6i1.8128 ◽

2020 ◽

Author(s):

Ekaterina Gerasimova ◽

Elizaveta Gumirova

Keyword(s):

Portland Cement ◽

Red Mud ◽

Waste Product ◽

Cement Stone ◽

Mathematical Planning ◽

Alumina Production ◽

Mineral Additive ◽

Composition Properties ◽

Planning Of Experiments ◽

Potential Use

The paper deals with the problem of utilization of red mud which is a waste product from alumina production using the Bayer method. The principal possible use for the red mud of JSC “Bogoslovsky aluminum plant” (Sverdlovsk region) for the compositions based on Portland cement is shown. It was found that the mud introduction accelerates beginning of the cement paste setting and thickens the paste reducing its mobility. It is concluded that the introduction of red mud up to 30 % is justified in terms of strength indicators. The work is carried out using mathematical planning of experiments. Keywords: red mud, Portland cement, active mineral additive, composition, properties, bauxite, chemical composition, cement stone strength, mathematical planning of experiments

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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 Cement Compositions with a Finely Dispersed Additive for Consolidation of Soil by the Injection

Materials Science Forum ◽

10.4028/www.scientific.net/msf.974.149 ◽

2019 ◽

Vol 974 ◽

pp. 149-155

Author(s):

Irina V. Kozlova ◽

Alexey E. Bespalov ◽

Alexandra V. Bespalova

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Mechanical Characteristics ◽

Cement Stone ◽

Soil Consolidation ◽

Injection Solution ◽

Concentrated Load ◽

Reduced Viscosity ◽

Injection Technology ◽

Physical And Mechanical Characteristics

Cement compositions prepared by mixing cement with a stabilized finely dispersed slag suspension, which allow improving the structural, physical and mechanical characteristics of the cement stone are considered. On the first day of hardening, the strength of modified specimens increased by 54%, at the grade age - by 43%, and the porosity decreased by 13.8 and 17.3%, respectively. The possibility of obtaining an injection solution for soil consolidation on the basis of Portland cement and a stabilized slag suspension with the concentration of a finely dispersed slag of 50 g/l is considered. Studies have shown that the injection solution under study has reduced viscosity and sedimentation, increased compressive strength. After 28 days of hardening, the strength was 14.2 MPa, which is higher than the recommended values for consolidation of soil under the foundations (4-6 MPa), and at a concentrated load, for the base under the foundations of the columns (9-10 MPa). The data obtained allows considering an injection solution based on Portland cement and slag suspension for the use in the injection technology of soil consolidation.

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Influence of Fly Ash and Basalt Fibers on Strength and Chloride Penetration Resistance of Self-Consolidating Concrete

Materials Science Forum ◽

10.4028/www.scientific.net/msf.866.3 ◽

2016 ◽

Vol 866 ◽

pp. 3-8 ◽

Cited By ~ 8

Author(s):

Osama Ahmed Mohamed ◽

Waddah Al Hawat

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Portland Cement ◽

Strength Properties ◽

Chloride Penetration ◽

Partial Replacement ◽

Basalt Fibers ◽

Self Consolidating Concrete ◽

Chloride Penetration Resistance ◽

Hardened Properties

Fly ash is a sustainable partial replacement of Portland cement that offers significant advantages in terms of fresh and hardened properties of concrete. This paper presents the findings of a study that aims at assessing the durability and strength properties of sustainable self-consolidating concrete (SCC) mixes in which Portland cement was partially replaced with 10%, 20%, 30%, and 40% fly ash. The study confirms that replacing Portland cement with fly ash at all of the percentages studied improves resistance of concrete to chloride penetration. The 40% fly ash mix exhibited the highest resistance to chloride penetration compared to the control mix. Despite the relative drop in compressive strength after 7 days of curing, the 28-day compressive strength of 40% SCC mix reached 55.75 MP, which is very close to the control mix. The study also confirms that adding 1%, 1.5%, and 2% basalt fibers, respectively, to the 40% fly ash mix improves the resistance to chloride penetration compared to the mix without basalt fibers.

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Investigating the Compressive Strength Properties of Concrete Using Some Common Ghanaian Ordinary Portland Cements

International Journal of Technology and Management Research ◽

10.47127/ijtmr.v6i2.135 ◽

2021 ◽

Vol 6 (2) ◽

pp. 154-166

Author(s):

K. S Akorli ◽

K Danso ◽

J Ayarkwa ◽

A Acheampong

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Ordinary Portland Cement ◽

Strength Properties ◽

Research Strategy ◽

Cementitious Material ◽

Direct Function ◽

Cross Sectional ◽

Portland Cements ◽

Concrete Production

In a general sense, concrete is made of cementitious material, aggregates and water but the mix productivity is one issues that affect the amount of strength concrete developed. The concrete mix productivity is a direct function of the amount and quality of the cementitious material. The commonest cementitious material used for concrete in Ghana like other countries in the world is the Ordinary Portland Cement. The research sort to investigate the compressive strength properties of concrete made from some common Ghanaian Ordinary Portland Cement brands mostly used in the countries construction industries. The research strategy adopted was experimental. The research was a cross –sectional studies and used laboratory tests to get information on all cements. Cement grade 42.5N, 42.5R and 32.5R were used. A total of one – hundred and eight (108) concrete cubes were made from nine different brands of Ordinary Portland Cement with a mix design of 1:2:4. No admixtures were used in the mix. It was established that, Ordinary Portland Cement Brand E of grade 42.5R has the highest compressive strength after 28 days. Some of the cement brand with grade 32.5R developed better strength than that of grade 42.5R. Based on the experiment conducted, it can be concluded that for the C15 (1:2:4) and C20 compressive strength as per IS 456:2000, Ordinary Portland Cement Brand E and G of grade 42.5R and Ordinary Portland Cement Brand H and J of grade of 32.5R satisfactory meets the requirement. It implies that some of the Ghanaians Portland Cement developed a satisfactory compressive strength and meets the minimum strength attainment after 28 days’ which is 15 N/mm2. Based on the result, it is recommended that Ordinary Portland Cement Brand E of grade 42.5R should be used for most concrete production and Ordinary Portland Cement Brand J of grade 32.5R can also be used for concrete work in the absence of E 42.5R. Citation: Akorli, K. S., Danso, K., Ayarkwa, J. and Acheampong, A. (2021). Investigating the Compressive Strength Properties of Concrete Using Some Common Ghanaian Ordinary Portland Cements. International Journal of Technology and Management Research (IJTMR), Vol. 6 (1): Pp.154-166.[Received: March 13, 2021Accepted: September 1, 2021

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MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL

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

10.12737/article_58e23e09e92025.32814168 ◽

2017 ◽

Vol 2 (3) ◽

pp. 9-18 ◽

Cited By ~ 1

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.

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The Effect of Fine Dispersed Slag Component on the Slag Portland Cement Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1011.103 ◽

2020 ◽

Vol 1011 ◽

pp. 103-108

Author(s):

Irina Kozlova ◽

Olga Zemskova ◽

Vyacheslav Semenov

Keyword(s):

Portland Cement ◽

Structural Characteristics ◽

Initial Period ◽

Cement Composite ◽

Cement Matrix ◽

Cement Stone ◽

Ultrafine Grinding ◽

Slag Component

Cement compositions based on slag Portland cement and fine dispersed slag component are considered. It has been established that the introduction of 1-3% fine slag obtained as a result of ultrafine grinding in a jet mill into the slag Portland cement composition provides an increase in the strength and structural characteristics of cement stone from the first day of hardening, which is important for slag cements. To ensure the fine dispersed slag particles’ stabilization in the cement matrix, the cement compositions were sealed with water with the addition of a plasticizer on either sulfa-naphthalene formaldehyde or polycarboxylate substrates in an amount of 0.5% of the cement composite content. In the research course it was found that in the initial stages of hardening and grade age, the strength of the samples containing a fine dispersed slag component and a sulfa-naphthalene formaldehyde-based plasticizer increased by 20%. When the cement composition is mixed with water with a polycarboxylate-based plasticizer, an increase in strength in the initial period of hardening by 60% is noted, at the vintage age - by 30%. At the same time, the porosity of the samples based on slag Portland cement with the addition of fine dispersed slag and one of the plasticizers in the initial period was reduced by 16-21%, at the vintage age - by 33-35%.

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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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Improving the Efficiency of Slag Portland Cement by Reducing Shrinkage Deformations

Materials Science Forum ◽

10.4028/www.scientific.net/msf.992.104 ◽

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.

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