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26УДК 693.542.4
DOI: https://doi.org/10.31659/0585-430X-2019-768-3-73-76
Т.А. АХВЕРДИЕВА, д-р техн. наук (tahirehaqverdi@gmail.com) Р. ДЖАФАРОВ, магистр (R.Jafarov@bos-shelf.com)
Азербайджанский архитектурно-строительный университет ^ 1073, Азербайджан, г. Баку, ул. А. Султановой, 5)
Влияние тонкомолотых минеральных добавок на свойства бетона
В строительстве гидротехнических сооружений различного назначения широко используют железобетонные изделия и конструкции. Проведенные авторами научные исследования посвящены получению вяжущих материалов различного состава при одинаковом расходе цемента и водоцементном отношении, бетонов с различными заполнителями на основе этих вяжущих и изучению условий их твердения. Установлена зависимость изменения водоцементного отношения и свойств бетона при использовании разных добавок. Авторами проведены исследования по улучшению основных свойств гидротехнического бетона за счет применения местных минеральных добавок: подвергнутых активации вулканических пород и техногенных отходов. Из местных вулканических пород использованы товузский трасс, джейранчёльская вулканическая зола, а в качестве техногенных отходов - отходы производства оксида алюминия Гянджинского глиноземного завода и мартеновские шлаки. В целях сравнения также проведены исследования с использованием микрокремнезема. Минеральные добавки вводили в смеси в размере 5-20% от расхода цемента. Изучалось воздействие минеральных добавок на основные строительно-технологические свойства бетонной смеси и на основные физико-механические свойства затвердевшего бетона. Сравнительный анализ полученных результатов показывает, что использование тонкомолотых добавок возможно при замене 5-15% цемента. Использование местных добавок оказывает такое же эффективное воздействие, как микрокремнезем. С этой целью местные добавки были домолоты до удельной поверхности 250, 370, 470, 560 м2/кг, а затем изготовлены тестовые образцы и испытаны после 28 дней нормального твердения. Анализ результатов испытаний позволяет сделать следующие выводы. Существует возможность уменьшить расход цемента на 5-10% с использованием активированного товузского трасса; снизить расход цемента на 5-15% с использованием активированной джейранчёльской вулканической золы; уменьшить расход цемента на 5% с использованием отходов производства оксида алюминия Гянджинского глиноземного завода; снизить расход цемента на 5-15% с использованием мартеновских шлаков. При этом основные свойства бетона сохранятся. Представлена динамика изменения прочности при сжатии образцов, изготовленных с использованием тонкодисперсных отходов в сравнении с бездобавочным бетоном.
Ключевые слова: гидротехнические сооружения, техногенные отходы, горная порода, структура, шлак, минеральные добавки, микрокремнезем, вулканическая зола.
Для цитирования: Ахвердиева Т.А., Джафаров Р. Влияние тонкомолотых минеральных добавок на свойства бетона // Строительные материалы. 2019. № 3. С. 73-76. 00!: https://doi.org/10.31659/0585-430X-2019-768-3-73-76
T.A. HAGVERDIYEVA, Doctor of Sciences (Engineering) (tahirehaqverdi@gmail.com), R. JAFAROV, Master (R.Jafarov@bos-shelf.com) Azerbaijani University of Architecture and Construction (AZ 1073, Azerbaijan, Baku, A. Sultanova St., 5)
Impact of Fine Ground Mineral Additives on Properties of Concrete
Nowadays concrete and reinforced concrete products and structures are widely used in the construction of various hydraulic facilities. A part of the scientific research carried out in this area is devoted to obtaining binding materials of different types and composition at the same cement consumption and water-cement ratio, concretes with different aggregates on the basis of these binders and the study of the conditions of their hardening. The dependence of changes in the water-cement ratio and properties of concrete when using different additives is established. The authors conducted the study aimed at improving the basic properties of hydraulic concrete mix due to the use of local mineral additives: volcanic rocks and techno-genic waste subjected to activation. From the local volcanic rock Tovuz trass, Jeyranchol volcanic ash and as technogenic waste - waste of aluminum production at the Ganja alumina refinery and open-hearth slag are used. Studies using microsilica have also been conducted for comparison purposes. Mineral additives were introduced into the mixture in the amount of 5-20% of the cement consumption. The effect of mineral additives on the basic construction and technological properties of concrete mix and on the basic physical and mechanical properties of hardened concrete was studied. Comparative analysis of the results shows the use of fine ground additives is possible when replacing 5-15% of cement. The use of these local additives has the same effective impact as microsilica. For this purpose, local additives were grinded to the specific surface of 250, 370, 470, 560 m2/kg, and then test samples were made and tested after 28 days of normal hardening. The analysis of test results suggests the following: cement consumption can be reduced by 5-10% using the activated Tovuz trass; cement consumption can be reduced by 5-15% using activated Jeyranchol volcanic ash; cement consumption can be reduced by 5% using industrial waste of aluminum oxide of Ganja alumina refinery plant; cement consumption can be reduced by 5-15% using open-hearth slag. In this case, the basic properties of concrete will remain. The dynamics of changes in the compressive strength of samples made with the use of fine disperse waste in comparison with non-additive concrete is presented.
Keywords: hydraulic engineering constructions, technogenic waste, rock, structure, slag, mineral additives microsilica volcanic ash.
For citation: Hagverdiyeva T.A., Jafarov R. Impact of fine ground mineral additives on properties of concrete. Stroitel'nye Materialy [Construction Materials]. 2019. No. 3, pp. 73-76. DOI: https://doi.org/10.31659/0585-430X-2019-768-3-73-76 (In Russian).
Actuality of the research: Nowadays concrete and reinforced concrete products and structures are widely used in the construction of various hydraulic facilities. Thus, hydraulic concrete with high performance indicators is used in the construction of hydraulic
structures and buildings, such as dams (without transition, closed on the one side, facilities for the accumulation and purification of polluted water); reservoirs, water fences, water pipes, canals, tunnels, grooves, test siphons, water lifting facilities, sluices,
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pools, protective installations, reclamation facilities, pumping stations, fishing reserves, hydroelectric power stations and other structures [1—8]. Therefore, such buildings and structures must meet specific requirements as durability, longevity, reliability, economic efficiency, as well as aesthetic requirements in design. In terms of engineering-geological construction, hydraulic structures must have basic building properties as load capacity, crack resistance, waterproofing, and reinforced on a soil base. These structures can be subject to constant and periodic loads and pressures. Holes may appear in the surface of the buildings and facilities that have been in operation for a long time or erosion may occur as a result of softening. There are also cases as abrasion of the surface of hydraulic structures due to the water being pumped to the buildings under high pressure [2]. Therefore, a special focus should be on durability of the concrete used for the construction of hydraulic structures and the achievement of a high operational properties which are still a matter of urgency [9—10].
A part of the scientific research carried out in this area is devoted to achieving adhesive materials of different types and composition, concrete with different aggregates in the fixed cement consumption and water/ cement ratio and the study of the conditions of their hardening. The performance properties have been studied by prior hardening and replacing cement with low calcium fly ash and it has been determined that this ratio has the opposite effect on these properties. It was also determined that the type of aggregate directly affects the water/cement ratio and the hardening process of the concrete. Porosity, gas impermeability and chloride penetration were found to be unreliable indicators which depends on the density of concrete. To determine the performance indicators of concrete, a method of accelerating carbonization has been applied, which is highly sensitive and due to which it has been established that the performance indicators of concrete are the same with the natural carbonation process [8—11].
The effect of such properties as the primary modulus of elasticity, the compressive strength limit of concrete, to which fly ash and air entraining additive has been applied, and was frosted/defrosted for 300 periods, has been studied, the mass loss determined and freeze-thaw resistance of such concrete as well as possibility of using this concrete under specific freezing/unfreezing conditions have been identified. The research presents the recommendations on the dosage of air-entraining additives and fly ash, as well as on the ratio of water and adhesive [3—7].
Ukrainian scientists collected and systematized the methods of obtaining of known and modified concrete mixtures and concrete. They analyzed the results and determined that the poly-functioning superplasticizer obtained on the basis of light pyrolysis resin is an effective additive. Concrete composition has been optimized by applying a new SV-7 super-plasticizer.
This additive has experimentally proved to accelerate the initial phase of hardening process of concrete, significantly reduce the water/cement ratio in the concrete mix, improve the quality of concrete, and increase its strength and durability [5; 6].
Aim of the study: In this research, a study was conducted in the direction of improving the basic properties of hydraulic concrete mix with the use of local volcanic rocks and technogenic waste as activated mineral additives.
Object of the study: At this stage of experiment, Tovuz trass, Jeyranchol volcanic ash have been used as activated local volcanic rocks and industrial waste of aluminum oxide from Ganja alumina refinery plant and open-hearth slag used as technogenic wastes. For comparison, experiments were also performed using finely dispersed micro silica.
Work progress: At the initial stage of the experiments, mineral additives were used by adding to the mixture in the amount of 5-20% of the cement consumption. The experimental effect of mineral additives on the basic structural and technological properties of concrete and the main physical and mechanical properties of hardened concrete were studied. Active mineral additives were used after being finely granulated in a laboratory mill. Concrete mixtures have been prepared by using ultra grained additives. Initially, compatibility index and average density of mixtures have been determined. The test results are shown in Table 1.
As it can be seen in Table 1, the fluidity of the initial concrete mixture is 2,5 cm whereas the sample prepared by consumption of 5 to 15% aggregates had a different impact on the fluidity of mixtures. The changes observed in the mixtures are as follows: mixed with the Tovuz trass, this indicator was 3,5; 4,5; 3 cm, with the Jeyranchol volcanic ash — 2,5; 3; 5 cm, no changes were observed in the sample with industrial waste of aluminum oxide of the Ganja alumina refinery plant (2.5 cm remained stable), samples with open-hearth slag — 3,5; 3; 3 cm and with fine dispersed micro silica additive 2,5; 3,5; 5,5 cm. The comparative analysis of the results shows the use of finely ground aggregates is possible with a cement consumption of 5-15%. The use of these local additives has the same effective impact as the finely ground silica-oxide.
The effect of granularity of ultrafine ground mineral additives on the basic physical and mechanical properties of concrete has been studied. The preliminary experiments and scientific studies show that the granularity of mineral components has a substantial effect on the properties of concrete. Considering the aforementioned, the effect of finely ground mineral raw material used in the experiments on the physical and mechanical properties of concrete has also been studied. The ultra-dispersive micro silico additive was also used in the experiments for comparison. For this purpose, the other finely ground components were grained to the extent of 250, 370, 470, 560 m2/kg, test samples
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Таблица 1 Table 1
Влияние тонкомолотых минеральных добавок на строительно-технологические свойства бетонной смеси The Impact of Finely Ground Additives on the Construction and Technological Properties of Concrete Mixture
Amount of additive, As per cement mass, % / Количество добавки, мас.% Construction and technological properties of concrete mixture / Строительно-технологические свойства бетонной смеси
Name of additive / Название добавки
Tovuz Trass / Товузский трасс Jeyranchol volcanic ash / Джейранчёльская вулканическая зола Industrial waste of aluminum oxide from the Ganja alumina refinery / Отходы производства оксида алюминия Гянджинского глиноземного завода Open-hearth slag / Мартеновский шлак Silica-oxide / Оксид кремния
Fluidity, cm / Подвижность, см Average density, kg /m3 / Средняя плотность, кг /м3 Fluidity, cm / Подвижность, см Average density, kg /m3 / Средняя плотность, кг /м3 Fluidity, cm / Подвижность, см Average density, kg /m3 / Средняя плотность, кг /м3 Fluidity, cm / Подвижность, см Average density, kg /m3 / Средняя плотность, кг /м3 Fluidity, cm / Подвижность, см Average density, kg /m3 / Средняя плотность, кг /м3
5 3,5 2365 2,5 2357 2,5 2360 5,5 2310 2,5 2325
10 4,5 2380 3 2350 2,5 2330 3,5 2405 3,5 2365
15 3 2345 5 2355 2,5 2330 3 2405 5,5 2365
20 2,5 2328 3 2335 2.5 2330 2.5 2405 3,8 2320
Таблица 2 Table 2
Влияние удельной поверхности минерально-активных добавок на основные физико-механические свойства бетона The Impact of the Specific Surface of Mineral-Active Additives on the Basic Physical and Mechanical Properties of Concrete
Additive name / Название добавки Physical-mechanical indicators of concrete / Физико-механические свойства бетона
Specific surface of mineral component / Удельная поверхность минеральной добавки
250 m2/kg 370 m2/kg 470 m2/kg 560 m2/kg
Concrete average density kg/m3/ Средняя плотность бетона, кг/м3 Compressive strength of concrete, MPa / Прочность при сжатии, Mna Concrete average density kg/m3/ Средняя плотность бетона, кг/м3 Compressive strength of concrete, MPa / Прочность при сжатии, Mna Concrete average density kg/m3/ Средняя плотность бетона, кг/м3 Compressive strength of concrete, MPa / Прочность при сжатии, Mna Concrete average density kg/m3 / Средняя плотность бетона, кг/м3 Compressive strength of concrete, MPa / Прочность при сжатии, MПa
Without additive/ Без добавки 2310 2325 39,02 38,8
Tovuz trass/ Товузский трасс 2267 2295 36,2 36,4 2310 2322 38.24 38.55 2373 2355 40,2 40,5 2499 2510 41,59 42,7
Jeyranchol volcano ash Джейранчёльская вулканическая зола 2215 2240 32,5 32,68 2320 2315 33,78 33,68 2380 2365 36,35 35,23 2402 2421 38,7 37,91
Industrial waste of aluminum oxide / Отходы производства оксида алюминия 2252 2240 28,6 29,2 2368 2350 32,64 32,88 2368 2350 33,89 33,98 2399 2408 37,62 37,08
Open-hearth slag/ Мартеновские шлаки 2259 2262 37,41 38,12 2329 2329 40,59 40,02 2398 2390 41,8 42,5 2560 2550 43,97 43,43
Micro silico / Микрокремнезем 2399 2384 36,21 36,19
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prepared and tested after 28 days of hardening. The test results of the samples are shown in table 2.
Conclusions: The analysis of test results suggests the following:
— Cement consumption can be reduced by 5—10% using the activated Tovuz trass;
— Cement consumption can be reduced by 5—15% using activated Jeyranchol volcano ash;
— Cement consumption can be reduced by 5% using industrial waste of aluminum oxide of Ganja alumina refinery plant;
— Cement consumption can be reduced by 5—15% using open-hearth slags;
— The possibility of obtaining concrete of the required grade by using the specified amount of the above mentioned additives has been determined.
— With an increase in the specific surface of mineral additives, the average density of hardened concrete rises, which indicates that the additives used contribute to the formation of a concrete stone with a more dense structure due to the filling of pores between the aggregates used in concrete with ultrafine additives.
— It has been established that the average density of samples made on the basis of activated natural mineral additives is 2215—2510 kg/cm3, the average density of
References
1. Jafarov R.M., Hagverdieva T.A. Determination of compressive strength of the concrete retaining wall of the harbor located at Baku Deep Water Jacket Plant by non-destructive method. Materials of the International Conference on the Perspectives for Development of the Construction Materials Industry in Azerbaijan, dedicated to the 40th Anniversary of the Azerbaijan University of Architecture and Construction. Baku, December 18, 2015, pp. 72-79. (In Azerbaijani).
2. Vernigorova V.N., Sadenko S.M. The structure of the concrete mix and the role of water in its physico-chemical conversion into concrete. Stroitel'nye Materialy [Construction Materials]. 2018. No. 4, pp. 52-55. (In Russian).
3. Rashad A. Preliminary study on the effect of fine aggregate replacement with metakaolin on strength and abrasion resistance of concrete. Construction and Building Materials. 2013. Vol. 44, pp. 487-495.
4. Vernigorova V.N., Sadenko S.M. On the non-stationarity of physico-chemical processes occurring in the concrete mixture Stroitel'nye Materialy [Construction Materials]. 2017. No. 1-2, pp. 86-89. (In Russian).
5. Savelieva M.A., Urkhanova L.A., Khardaev P.K. Prospects for the use of colloidal additives for the modification of cement stone. Stroitel'nye Materialy [Construction Materials]. 2017. No. 11, pp. 59-63. (In Russian).
6. Bazhenov Yu.M., Falikman V.R., Bulgakov B.I. Nanomaterials and nanotechnologies in modern technology of concrete. Vestnik MGSU. 2012. No. 12, pp. 125-133. (In Russian).
samples made on the basis of industrial waste is 22402560 kg/cm3, which is 7-10% higher from the average density of the concrete made on the basis of conventional concrete mixture.
- Compressive strength test results of the stone materials with the same composition show that with an increase in the specific surface of active mineral additives, compressive strength of concrete stone also increases. In comparison with the concrete made on the basis of ordinary concrete mix without an additive, it was found that the indicators of samples with activated volcanic rocks is higher by 2-9%, and in samples with open-hearth slags - by 12%.
- The compressive strength of the specimens prepared by using industrial waste of aluminum oxide of the Ganja alumina refinery plant, of which is crushed to 560 m2/kg was reduced to 3% compared to the concrete made from the concrete mix without additives. The specific surface of this additive shows increasing indicators in the range of 250-260 m2/kg, which requires finer grinding.
A comparative analysis of the results of samples based on ultrafine silica-oxide and with active mineral additives shows that the compressive strength of the samples is 0,3-12,4% higher. This allows us to state that the additives used are more active and effective.
7. Hagverdiyeva T.A., Jafarov R.M. X-ray phase analysis of the concrete modified with complex additives for hydraulic installations. International Scientific-Practical Conference on Water, Energy Supply and Ecological Problems in Modern Construction. Baku, November 27-28, 2018, pp. 92-95. (In Azerbaijani).
8. Anisimov S.N., Kononova O.V., Minakov Y.A., Leshkanov A.Yu., Smirnov A.O. Study of the strength of heavy concrete with plasticizing and mineral additives. Modern problems of science and education. 2015. No. 2-1. http://www.science-education.ru/ru/ article/view?id=21276 (Date of access: 11/13/2018). (In Russian).
9. Kastorny L.I., Detochenko I.A., Arinina E.S. Influence of water retaining additives on some properties of self-compacting concrete. Part 2. Rheological characteristics of concrete mixes and strength of self-compacting concrete. Stroitel'nye Materialy [Construction Materials]. 2017. No. 11, pp. 22-27. (In Russian).
10. Kastorny L.I., Rautkin A.V., Raev A.S. Influence of water retaining additives on some properties of self-compacting concrete. Part 2. Rheological characteristics of concrete mixes and strength of self-compacting concrete. Stroitel'nye Materialy [Construction Materials]. 2017. No. 7, pp. 34-38. (In Russian).
11. Ivashchenko Yu.G., Kozlov N.A. Complex organo-mineral modifier for high-quality concrete. International Scientific Conference «Mathematical methods in engineering and technology» MMTT-25. Volgograd, May 29-31, 2012, pp. 164-166. (In Russian).
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