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14УДК 691.327:691.214.8
САМОУПЛОТНЯЮЩИЕСЯ МЕЛКОЗЕРНИСТЫЕ БЕТОНЫ НА ОСНОВЕ
ВЫСОКОНАПОЛНЕННЫХ ЦЕМЕНТНЫХ ВЯЖУЩИХ
А.С. Балыков, Т.А. Низина, В.В. Володин, Д.И. Коровкин
Артемий Сергеевич Балыков
Кафедра строительных конструкций, Национальный исследовательский Мордовский государственный университет им. Н.П. Огарёва, ул. Большевистская, 68, Саранск, Республика Мордовия, Российская Федерация, 430005
E-mail: artbalrun@yandex. ru Татьяна Анатольевна Низина
Кафедра строительных конструкций, Национальный исследовательский Мордовский государственный университет им. Н.П. Огарёва, ул. Большевистская, 68, Саранск, Республика Мордовия, Российская Федерация, 430005 E-mail: nizinata@yandex. ru
Владимир Владимирович Володин
Кафедра строительных конструкций, Национальный исследовательский Мордовский государственный университет им. Н.П. Огарёва, ул. Большевистская, 68, Саранск, Республика Мордовия, Российская Федерация, 430005 E-mail: [email protected]
Дмитрий Игоревич Коровкин
Кафедра строительных конструкций, Национальный исследовательский Мордовский государственный университет им. Н.П. Огарёва, ул. Большевистская, 68, Саранск, Республика Мордовия, Российская Федерация, 430005 E-mail: [email protected]
Настоящая работа посвящена разработке модифицированных мелкозернистых бетонов классов прочности на сжатие от В20 до В90 из самоуплотняющихся смесей, содержащих микрокальцит, суперпластификатор на основе эфира поликарбокси-лата, мелкий кварцевый песок с модулем крупности 1,4, минеральные добавки микрокремнезема, метакаолина и Пенетрон Адмикс (при необходимости). Приведены результаты исследования физико - механических свойств разработанных самоуплотняющихся мелкозернистых бетонов.
Ключевые слова: мелкозернистый бетон, высоконаполненная самоуплотняющаяся смесь, карбонатный наполнитель, активная минеральная добавка, мелкий песок, физико - механические свойства
Для цитирования:
Балыков А.С., Низина Т.А., Володин В.В., Коровкин Д.И. Самоуплотняющиеся мелкозернистые бетоны на основе высоконаполненных цементных вяжущих. Умные композиты в строительстве.
2021. Т. 2. №. 2. С. 32-37 URL: http://comincon.ru/index.php/tor/issue/view/V2N2_2021
DOI: 10.52957/27821919_2021_2_32
том 2, ВЫПУСК 2, 2021 vol 2, issue 2 УМНЫЕ КОМПОЗИТЫ В СТРОИТЕЛЬСТВЕ
SMART COMPOSITE IN CONSTRUCTION
UDC 691.327:691.214.8
SELF-COMPACTING FINE-GRAINED CONCRETES
BASED ON HIGHLY FILLED CEMENT BINDERS
A.S. Balykov, T.A. Nizina, V.V. Volodin, D.I. Korovkin
Artemy S. Balykov
Department of Building Structures, N. P. Ogarev National Research Mordovian State Uni-versity, 68 ulitsa Bolshevistskaya, Saransk, Republic of Mordovia, 430005, Russia
E-mail: artbalrun@yandex. ru Tatyana A. Nizina
Department of Building Structures, N. P. Ogarev National Research Mordovian State Uni-versity, 68 ulitsa Bolshevistskaya, Saransk, Republic of Mordovia, 430005, Russia E-mail: nizinata@yandex. ru
Vladimir V. Volodin
Department of Building Structures, N. P. Ogarev National Research Mordovian State Uni-versity, 68 ulitsa Bolshevistskaya, Saransk, Republic of Mordovia, 430005, Russia E-mail: [email protected]
Dmitry I. Korovkin
Department of Building Structures, N. P. Ogarev National Research Mordovian State Uni-versity, 68 ulitsa Bolshevistskaya, Saransk, Republic of Mordovia, 430005, Russia E-mail: [email protected]
The paper discusses the development of modified fine-grained concretes of C20 to C90 compressive strength classes from self-compacting mixtures containing microcalcite, polycar-boxylate superplasticizer, and fine quartz sand with a fineness modulus of 1.4, mineral additives of microsilica, metakaolin and Penetron Ad-mix (if necessary). The work provides the results of the study of physical and mechanical properties of the de-veloped self-compacting fine-grained concretes.
Key words: fine-grained concrete, highly filled self-compacting mixture, carbonate filler, active mineral additive, fine sand, physical and mechanical properties
For citation:
Balykov A.S., Nizina T.A., Volodin V.V., Korovkin D.I. Self-compacting fine-grained concretes based on
highly filled cement binders. Smart Composite in Construction. 2021. Vol. 2. No 2. Р. 32-37 URL: http://comincon.ru/index.php/tor/issue/view/V2N2_2021
DOI: 10.52957/27821919_2021_2_32
Cement-based concrete remains the basic building material. The reliability and durability of building products and structures depend on its performance properties. The modification of cement systems with chemical and mineral additives of different compositions, used both individually and in complex, is one of the main means of controlling structure formation and improvement of physical and mechanical properties of concrete [1, 2].
The range of mineral additives used in the formulation of cement systems nowadays is very extensive and consists of a variety of natural and synthetic materials. At the same time, the following types of mineral modifiers showed the greatest efficiency in compositions of cement concrete: siliceous and aluminosilicate pozzolanic additives (metakaolin, microsilica, etc.); expanding sulphoaluminium type additives; carbonate fillers (limestone, dolomitized limestone, dolomites, etc.) [3, 4].
Application of effective individual chemical and mineral additives as well as complex organic-mineral modifiers promoted the creation of high strength modified concretes, including self-compacting mixtures (SCC) [5, 6], first researched by the Japanese professor H. Okamura [7]. It is known that SCCs are unique due to high technological indicators (standard cone spreading over 550
SMART COMPOSITE IN CONSTRUCTION
mm), which have the increased rheological efficiency of the suspension matrix.
It is worth to look into the development of highly mobile concrete mixtures with fine sands. The difficulty in achieving self-compaction of these systems, especially with reduced binder content, is due to the high thickening ability of fine sands, as well as the reduced efficiency of plasticizers in lean concrete mixes [8]. It means that the problem of increasing rheological efficiency of modern plasticizers in cement systems with aggregates from fine and water-demanding sands seems is yet to be solved. In addition, it is necessary to optimize the granulometric composition and dosage of mineral additives in this kind of compositions to ensure their high fluidity at a reduced water content.
The aim of this work was to develop compositions of self-compacting concrete mixtures using fine silica sand. The main components of the cement systems used were: Portland cement CEM I 32.5B (PC); fine quartz sand with particle size modulus 1.4 (FQS); carbonate filler — KM100 grade microcalcite (MCM) in accordance with GOST R 56775-2015; condensed non-compacted micro-silica MK-85 (MCN); highly active metakaolin (MTK); additive Penetron Admix (Admix); polycarboxylate ester-based superplas-ticizer Melflux 5581 F (SP).
Table 1. Compositions and physical-mechanical properties of cement systems under study
Composition number 1 2 3 4 5 6 7
Recipe and process parameters
PC, kg/m3 701+739 239+485
FQS/PC 1.50 2.23 2.92 4.68
MCM/PC 0.45 1.11 1.63 3.21
Modifier (MD), % of mass (PC+MD) - 10 VMC 10 (Admix) 10 (MC) 10 VMC - -
SP, % of mass (PC+MCM) 0.7
Water-cement ratio 0.29 0.30 0.32 0.32 0.44 0.57 0.89
Flow of Hagerman cone, mm 295 260 280 280 260 290 300
Physical and mechanical properties in 28 days
Density, kg/m3 2393 2343 2320 2367 2320 2323 2344
Flexural strength, MPa 12.3 12.8 10.6 14.9 9.9 7.4 5.3
Compressive strength, MPa 92.5 104.2 82.7 115.8 73.8 47.5 28.3
Table 1 presents the developed compositions of self-compacting fine-grained concretes. Basic formulation parameters of the obtained cement systems: cement consumption — 239-739 kg/m3, microcalcite dosage — 45-321 % of cement mass, water content and superplasticizer consumption — 20.2-21.8 and 0.7% of Portland cement + microcalcite mixture mass, respectively (Table 1). A distinctive feature of these self-compacting mixtures is an increased degree of microcalcite filling, which determines the high content of rheologically active fine-dispersed components (PC + MCM) (at least 340 l/m3), as well as the increased volume of rheologically active suspension matrix (PC + MCM + mineral additive + water) (at least 580 l/m3), which provides necessary separation of fine sand grains and high technological parameters of concrete
mixtures (Hagerman cone and standard Abrams cone flow diameter at least 260 and 500 mm respectively).
The testing provided with physical and mechanical properties of self-compacting fine-grained concretes with fine sand FQS in 28 days: density, bending, and compressive strength are 2320-2393 kg/m3, 5.3-14.9, and28.3-115.8MPa, respectively.
The test results confirm that it is possible to obtain self-compacting fine-grained concretes of high strength without active mineral modifiers, as evidenced by the level of strength indicators achieved in the design age for the composition number 1 with Portland cement 739 kg/m3 — 92.5 and 12.3 MPa in compression and flexure, respectively. At the same time, the replacement of 10 % of Portland cement by metakaolin (composition No. 2) and microsilica (composition No. 4) contributes to increasing the strength
characteristics of cements relative to concrete of control composition No. 1 (up to 21 and 25% in flexure and compression, respectively). On the contrary, the introduction of Admix into composition No. 3 results in 14 and 11% decreases of flexural and compressive strengths of fine-grained concrete, which may be due to a somewhat increased thickening ability of this mineral additive, as well as to the unique aspects of its influence on the structure parameters of the obtained composites.
The study was conducted with the financial support of RFBR, research project No. 18-29-12036.
REFERENCES
SMART COMPOSITE IN CONSTRUCTION
1. Kalashnikov V.I. Calculation of compositions of high-strength self-compacting concrete. 2008. N. 10. P. 4-6 (in Russian).
2. 2. Tarakanov O.V., Kalashnikov V.I. Prospects of application of complex additives in new generation concrete. Izvestiya KGASU. 2017. N 1(39). P. 223-229 (in Russian).
3. 3. Usherov-Marshak A.V. Betony novogo genereniya - betony s dopadkami. Beton i zhelezobeton. Equipment. Materials. Technologies. 2011. N1. P. 78-81 (in Russian).
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5. 5. Schutter G. De., Bartos P., Domone P., Gibbs J. Self-compacting concrete. New-York: Taylor & Francis Group. 2008. 296 p.
6. 6. EFNARC. The European guidelines for self-compacting concrete. Specification, production and use. Farnham. UK. 2005. 68 p.
7. 7. Okamura H., Ouchi M. Self-compacting concrete. Journal of Advanced Concrete Technology. 2003. V. 1. N. 1. P. 5-15.
8. 8. Nizina T.A., Balykov A.S., Korovkin D.I., Volodin V.V.
Modified fine-grained concretes based on highly filled self-compacting mixtures. IOP Conference Series: Materials Science and Engineering. 2019. V. 481. URL: https://doi.org/10.1088/1757-899X/481/1/012048
Received 16.06.2021 Accepted 21.06.2021
