Binder composites for concretes with improved shock resistance

Федюк, Роман; Mochalov, Aleksandr; Pezin, D. N.; Liseitsev, Yu. L.

doi:10.30791/1028-978x-2019-6-25-35

Cited by 12 publications

(9 citation statements)

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“…This is due to the need to: reduce the cost of implementing the selfcleaning process in building composites, simplify and increase the uniformity of the distribution of the nanoscale photocatalyst in the near-surface layer and increase the surface area of the photocatalyst interacting with electromagnetic radiation and pollutant molecules. The research results show that an effective PCM for construction can be obtained by depositing titanium dioxide on a silica support [8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 93%

Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials

et al. 2021

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Compositions and technology for obtaining a photocatalytic composite material (PCM) by deposition of titanium dioxide particles synthesized by the sol–gel method on a silica support of various types (microsilica, gaize and diatomite) have been developed. The properties (chemical and mineral composition, dispersion, specific surface area, porosity, ζ-potential, acid–base properties, and microstructure) of microsilica, gaize and diatomite were studied to assess the effectiveness of using a photocatalytic agent as a carrier. In terms of specific viscosity (ηsp = 45), the concentration of the precursor (tetrabutoxytitanium—TBT) is set at 22 vol. % in a solvent (ethanol), at which it is possible to obtain the maximum amount of dissolved film oligomer without the formation of an aggregate-like precipitate. Modification of the reaction mixture (precursor: ethanol = 1:3) by replacing part of the solvent with a Span-60 surfactant/TBT = 1–1.1 made it possible to obtain polydisperse titanium dioxide particles with peak sizes of 43 nm and 690 nm according to laser granulometry data. Taking into account the interaction of titanium complexes with the surface of a silica support, a phenomenological model of the processes of structure formation of a photocatalytic composite material is proposed. By the value of the decomposition of rhodamine B, the photocatalytic activity of the developed composite materials was determined: PCM based on diatomite—86%; PCM based on microsilica—85%; PCM based on gaize—57%.

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Section: Introductionmentioning

confidence: 93%

Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials

et al. 2021

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“…In contrast, CNT functionalization delayed the cement hydration kinetics, and such delay increased as the acid exposure time increased: the main heat flow peak reduced down to 1.98 mW/g of cement and occurred up to 25.6 h for CNT-9. The polar groups created by the acid functionalization (e.g., -COH and -COOH) can bind with the Ca(OH) 2 formed by cement hydration reactions [29,30]. Since the saturation of Ca 2+ and consequent precipitation of Ca(OH) 2 is recognized as the trigger for the end of the induction period [35], the capture of Ca 2+ ions by those groups can delay that saturation and consequently the overall cement reactions.…”

Section: Cement Hydration Kineticsmentioning

confidence: 99%

“…In this condition, oxygen atoms from the acid can react with the carbon atoms of the defect sites and/or ends of CNT. As a consequence, some polar groups may be formed (e.g., -COH and -COOH), improving the wettability of CNT in water [29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Combined Functionalization of Carbon Nanotubes (CNT) Fibers with H2SO4/HNO3 and Ca(OH)2 for Addition in Cementitious Matrix

Batiston

Matos

Gleize

et al. 2021

Fibers

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Acid treatment is commonly used to improve the dispersion of carbon nanotubes (CNT) in a cementitious matrix, but it causes undesired delay on cement hydration kinetics. This work reports a combined CNT functionalization method with H2SO4/HNO3 and Ca(OH)2 for addition in a cementitious matrix. Results showed that the Ca(OH)2 exposure neutralized the active sites generated by acid exposure, compensating the delay in hydration. As a result, CNT exposed to H2SO4/HNO3 for 9 h and further Ca(OH)2 treatment led to equivalent hydration kinetics than un-treated CNT did with improved stability.

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“…An examination of previous studies from the literature showed that the use of agglomeration to create aggregates is often deployed in the preparation of various composites, favorably affecting energy efficiency and the environmental friendliness of production [31][32][33][34][35]. Some studies concerning lightweight concrete filled with cold-bonded fly ash with a low thermal conductivity coefficient were recently carried out at the St. Petersburg Polytechnic University [36,37].…”

Section: Of 12mentioning

confidence: 99%

Granular Aggregates Based on Finely Dispersed Substandard Raw Materials

et al. 2021

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It is necessary to solve the ecological problems of regions where there is large-tonnage storage of various finely dispersed materials, including technogenic ones. This article presents the results of an investigation into the possible use of substandard dispersed quartz sands to obtain effective granular aggregates, with the purpose of putting them to use in mortars and concrete. The study used standard and original experimental research methods related to the analysis and preparation of raw materials, technological tests, and the study of the properties of finished composites. Investigations were carried out to obtain composite binders in the component composition of which the use of different ratios of Portland cement and substandard quartz sands prepared in a vortex jet mill was envisaged. It was found that the obtained composite binders had high physical and mechanical characteristics, which was due to the high specific surface area and hydration activity. On the basis of composite binders and finely dispersed quartz sands (fineness from ≤0.16 mm to 1 mm), the granulation of mixtures of 36 types of component compositions was performed. The developed compositions of granular aggregates (GAs) showed the possibility of obtaining them with sufficiently high strength values in cement stone. The studies carried out make it possible to recommend finely dispersed substandard and technogenic materials for the production of GAs, which would ensure the economy of binding materials as well as contribute to the reuse of large-tonnage waste of ferrous and nonferrous metallurgy and the chemical and mining industries.

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Binder composites for concretes with improved shock resistance

Cited by 12 publications

References 0 publications

Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials

Obtaining and Properties of a Photocatalytic Composite Material of the “SiO2–TiO2” System Based on Various Types of Silica Raw Materials

Combined Functionalization of Carbon Nanotubes (CNT) Fibers with H2SO4/HNO3 and Ca(OH)2 for Addition in Cementitious Matrix

Granular Aggregates Based on Finely Dispersed Substandard Raw Materials

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