Construction Material Engineering

INFLUENCE OF QUARTZ FLOUR ON TECHNOLOGICAL PROPERTIES OF SELF-COMPLETED CONCRETE MIXTURES

Vestnik MGSU 6/2018 Volume 13
  • Pustovgar Andrey Petrovich - Moscow State University of Civil Engineering (National Research University) (MGSU) candidate of technical sciences, assistant professor, Vice Rector for Research, scientific director of the Research Institute of Building Materials and Technologies (SRI SMiT), Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Ivanova Irina Sergeevna - Moscow State University of Civil Engineering (National Research University) (MGSU) research worker Research Institute of Building Materials and Technologies (SRI SMiT), Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Elenova Aurika Almazovna - Moscow State University of Civil Engineering (National Research University) (MGSU) candidate of technical sciences, head Research Laboratory of Building Composites, Solutions and Concretes, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Abramova Anastasiya Yurʹevna - Moscow State University of Civil Engineering (National Research University) (MGSU) junior research worker of Research Institute of Building Materials and Technologies (SRI SMiT), Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Adamtsevich Aleksey Olegovich - Moscow State University of Civil Engineering (National Research University) (MGSU) candidate of technical sciences, senior research worker of Head of the Department of Scientific Policy, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.

Pages 717-728

Subject: technological properties of self-compensating concrete mixtures with a fine-grained microfiller, represented by quartz flour. Objectives: to determine the quantitative parameters of the influence of the granulometric composition of quartz flour and its dosages on the workability and delamination of self-compacting concrete mixtures with a constant consumption of gauged water and various contents of the superplasticizing additive. Materials and methods: portland cement CЕМ II/A-S 42,5N was used in the work; natural pit sand of 0…5 mm fraction; crushed stone of fraction 5...20 mm; Silverbond quartz flour with an average particle size of 17 μm and 34 μm (grades 15 and 30, respectively); Superplasticizer based on polycarboxylate ester GLENIUM®115. The grain size composition of microfillers was investigated by laser diffractometry using the laser particle analyzer "Analysette 22" COMPACT in accordance with ISO 13320-1: 2009. The mobility of the cone flow diameter and the delamination of the concrete mixture were measured in accordance with GOST 10181. Results: it was researched the influence of quartz flour of various granulometric composition (with an average particle size of 17 μm and 34 μm), applied in dosages of 50, 100 and 150 kg/m3, on the technological properties of self-compacting concrete mixtures with different superplasticizer content (2, 4, 6 and 8 l/m3) and a constant flow of gauged water, as a result of which it has been established that the use of quartz flour of finer grinding provides higher values of SCC mobility under the condition of equal content of superplasticer and gauged water; when using a more coarse quartz flour, the growth of the dosage of the superplasticizer causes a more pronounced increase in the mobility of the concrete mixture; increasing the dosage of quartz flour allows to reduce the delamination of SCC. Conclusions: experimental studies have shown the effectiveness of the use of quartz flour for obtaining SCCs of various classes of workability (SF1 ... SF3) and resistance to delamination (SR1, SR2) and have established that the use of quartz flour D50 = 34 μm leads to insufficient optimization of the granulometric of the composition of the SCC and, as a consequence, stratification of the mixture with its low mobility, whereas the thinner fraction D50 = 17 μm, of the same type of microfiller, makes it possible to obtain resistant to the delamination of any SCC in for the workability due to varying dosages of both the microfiller and superplasticizer.

DOI: 10.22227/1997-0935.2018.6.717-728

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The influence of plasticizers on the properties of gypsum binders activated in vortex layer apparatus

Vestnik MGSU 3/2019 Volume 14
  • Ibragimov Ruslan A. - Kazan State University of Architecture and Engineering (KSUAE) Candidate of Technical Sciences, Associate Professor, Head of the Department of Technology of building processes, Kazan State University of Architecture and Engineering (KSUAE), 1 Zelenaya st., Kazan, 420043, Russian Federation.
  • Korolev Evgeny V. - Moscow State University of Civil Engineering (National Research University) (MGSU) Doctor of Technical Sciences, Professor, Vice rector, Moscow State University of Civil Engineering (National Research University) (MGSU), 6 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Deberdeev Timur R. - Kazan National Research Technological University (KNRTU) Doctor of Technical Sciences, Professor, Head of the Department of Technologies for processing polymers and composite materials, Kazan National Research Technological University (KNRTU), 68 Karl Marx st., Kazan, 420015, Russian Federation.

Pages 293-300

Introduction. The article presents the results of a study to determine the influence of introduction method, type and concentration of plasticizing additives on the structure parameters and properties of gypsum stone obtained using gypsum cement treated in a vortex layer apparatus. Materials and methods. The G-5 BII gypsum cement was used for the investigation. The physicomechanical properties of the gypsum stone were determined in accordance with standard procedures, specific surface area was determined by air permeability, X-ray patterns were taken by means of the D2 Phaser diffractometer. Results. The data were obtained from 11 compositions of gypsum binder processed in the vortex layer apparatus and compared with a reference composition in the sense of the specific surface of the binder, mineralogical composition and physicomechanical characteristics of the gypsum stone. Conclusions. As a result of the investigation, it was revealed that the processing of the gypsum binder in the vortex layer apparatus leads to an increase in the specific surface up to 2 times. Modification of gypsum with MF superplasticizer significantly increases the ultimate compression strength (by 323 %) and bending strength (by 218 %) of the gypsum stone, as compared with the initial composition. Meanwhile the combined activation of gypsum with superplasticizers leads to a sharp decrease in strength and a significant slowdown in hydration. The greatest increase in the strength of the gypsum stone is observed when modifying activated gypsum. So, depending on the type of superplasticizer, the compression strength increases by 100 to 302 %, and bending strength by 86 to 218 %. Also this significantly reduces the gypsum stone overall porosity (down to 23 %) and softening coefficient (down to 51%).

DOI: 10.22227/1997-0935.2019.3.293-300

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