To see the other types of publications on this topic, follow the link: Polycarboxylate additives.
Journal articles on the topic 'Polycarboxylate additives'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Polycarboxylate additives.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Yukhnevskiy, P. I., and N. P. Dimitriadi. "About Synergistic Effect of Lubricant and Chemical Additives on Obtaining Quality Surface of Concrete Products." Science & Technique 18, no. 4 (2019): 303–10. http://dx.doi.org/10.21122/2227-1031-2019-18-4-303-310.
Full textAbstract:
The paper substantiates scientific background for development of lubricant compositions used in moulds for concrete products with high-quality surface. It has been shown that consideration of interaction between air bubbles, lubricant and liquid phase of modified concrete is of great importance. A release agent must allow air to migrate to a certain extent and leave “formwork – concrete mix” interface. In this regard the lubricant must have low viscosity. In addition, the lubricant should give maximum hydrophobization to a mould and have minimal adhesion in respect of the concrete mix. Additives of hydrophobic substances in liquid lubricants significantly reduce surface porosity of products. Chemical plasticizing additives and, in particular, additives of polycarboxylate type substantially reduce surface tension of liquid sгж, thereby they significantly reduce work for fixing an air bubble on concrete surface and contribute to its ejection. In addition, adsorbed molecules of the chemical additives interfere with interaction of cement paste particles and mould surface. Polycarboxylate additive molecules diffuse from a diffuse layer of the concrete mix, fill capillaries in the lubricant film, reduce its viscosity, act as additives that regulate spreading of lubricant and facilitate removal of air bubbles in a surface layer. Experimental studies of the combined effect while using low viscosity grease based on vegetable oils and modifying additives have confirmed the above provisions. The polycarboxylate-based additive has made the greatest impact on reduction of concrete surface porosity and content of all types of pores in the concrete has been approximately at the same level.
2
Tolmachov, Serhii, Olena Belichenko, Oleksandr Moskalenkо, and Yurii Pokusa. "Study of the influence of modern superplastificators on the properties of road cement concrete." Bulletin of Kharkov National Automobile and Highway University 2, no. 92 (2021): 74. http://dx.doi.org/10.30977/bul.2219-5548.2021.92.2.74.
Full textAbstract:
Abstract. In the technology of road concrete, the use of plasticizing additives is mandatory. In the last century, the most widely used plasticizers are lignosulfonates. These additives reduce the water demand of concrete mixtures by 10...15 % and increase the strength of concrete by 20...25 %. However, the presence of sugars in their composition leads to a strong slowdown of the hardening processes and can lead to a decrease the strength of concrete at the age of 28 days. In this century, modern superplasticizers based on polycarboxylates began to be widely used in industrial and civil construction. They were mainly used for the manufacture of cast concrete mixtures. On the other hand, their use in moderately mobile concrete mixes allows reducing water demand by 35...40 % and increasing strength by 60...100 % compared to concretes without additives. However, in such mixtures the use of polycarboxylates leads to a quick setting of the ce-ment and an accelerated set of concrete strength. This does not meet the requirements of the road concrete standards. The goal of the work is to study the influence of modern chemical additives of various nature on the basic properties of road cement con-crete. The article is devoted to the actual problem of the effective use of polycarboxylate superplasticizers
3
Fu, Zhong Jun, Feng Song, Lu Shan Yu, and Hong Wang. "Property of Water-Reducing and Crystallization on Superplasticize of the Concrete." Applied Mechanics and Materials 357-360 (August 2013): 1171–75. http://dx.doi.org/10.4028/www.scientific.net/amm.357-360.1171.
Full textAbstract:
In this paper, the effects of the water-reducing agent on the hydration property and the formation of the ettringite crystal of the concrete C3A were studied. Based on the thermometry analysis, the experiments of the effection of the hydration temperature on such concrete with both naphthalene- and polycarboxylate-type superplasticizers were conducted. The results could be drawn that the additives could prevent the slurry being hydrated in 1h, and decrease the hydration temperature. With the increasing of the additives, the hydration-inhibitory action of the additives was improved, too. The effect of the naphthalene- and polycarboxylate-type superplasticizers on the solubility property of C3A was also studied with EDTA titration, and the results showed that they can suppress the crystallization of the ettringite.
4
Talipov, Linar N., Evgeny G. Velichko, and Vyacheslav S. Semenov. "Study of synergetic effect of the complex polycarboxylate anti-corrosion additive in the model of pore concrete fluid." Vestnik MGSU, no. 6 (June 2020): 824–33. http://dx.doi.org/10.22227/1997-0935.2020.6.824-833.
Full textAbstract:
Introduction. Corrosion of reinforcement in concrete structures is rather expensive for the economy of any country. Current statutory documents offer two main directions — primary and secondary protection. One of the promising areas of primary protection methods is the use of complex anti-corrosion additives in concrete due to its technological simplicity and economic efficiency. Passivators and surfactants (SAS), as components of such additives, are of particular interest. Sodium nitrite is offered as a passivator, and polycarboxylate molecules (PCE) — as a SAS. The additive of sodium nitrite together with PCE has a visual synergistic effect.
 Materials and methods. Identification of structural characteristics of the molecules of the obtained PCE polymers was determined by methods of exclusion gel-permeation chromatography and 13C NMR spectroscopy. To study the synergetic effect of NaNO2 + PCE additive, the samples were kept in the models of pore liquid, after which the morphology of their surface was studied by methods of scanning electron microscopy and electron probe microanalysis.
 Results. The texture and surface color of the presented micrographs indicate surface formations on the samples stored in the models of pore liquid with different anti-corrosion additives. Electron probe microanalysis showed increased concentrations of carbon, oxygen and sodium on the surface of samples stored in pore concrete liquid models with the addition of a complex anti-corrosion additive of sodium nitrite and PCE, which indicates increased concentrations of PCE and possible increased pH on the steel surface. Based on the data acquired, the mechanism of formation of a protective film layer using complex anti-corrosion additive NaNO2 + PCE is offered.
 Conclusions. Justification of synergetic effect of complex polycarboxylate anti-corrosion additive in the model of concrete pore liquid opens up prospects for research of such additives to the concrete model.
5
Zajceva, Ljajsjan, Ekaterina Lucyk, Tat’jana Latypova, Valerij Latypov, Pavel Fedorov, and Madina Salamanova. "Influence of the Type of Aggregate from Industrial Waste on Corrosion Resistance of Modified Fine-Grained Concrete." Buildings 11, no. 8 (2021): 352. http://dx.doi.org/10.3390/buildings11080352.
Full textAbstract:
The development and implementation of “green” technologies in the construction sector, which ensure natural resource conservation, reduce harmful emissions and provide utilization of industrial waste, are key issues in material engineering of the XXI century. Extensive research has been devoted to solving these issues, including research in the field of concrete science. Still, the issue of developing concrete compositions with increased corrosion resistance remains much less studied. At the same time, reactive aggregates from industrial waste can have positive effect on durability of concrete, and the best result can be achieved by means of modification of a concrete mixture with highly effective additives. The article presents the research data in two lines—the study of applicability of reactive aggregates from waste products of nonmetallic and ceramic industries, mineral wool production and concrete scrap for production of corrosion-resistant concretes, as well as the assessment of possibility of Portland cement quantity reduction in a concrete mixture on local raw materials due to the introduction of additives based on polycarboxylates. The article presents the research evidence of the effect of dust and clay particles content on the quality of concrete with a polycarboxylate additive. The article describes the studies of corrosion resistance of concrete samples based on production wastes in sulfate environments and under the influence of carbon dioxide. The developed concrete compositions with waste use can be recommended for widespread application, rational use of resources, and production of durable high-quality concretes. The application of additives based on polycarboxylates makes it possible to produce concretes with the reduction of cement consumption in the mixture by 10–20% and decrease in the mode of thermo-wet treatment by two times.
6
Svisch, I. "INVESTIGATION OF STRENGTH GAIN OF HEAVY CONCRETE IN AN AGGRESSIVE ENVIRONMENT. USING SULPHATE-RESISTANT CEMENT." Construction and industrial safety, no. 35 (December 28, 2024): 21–27. https://doi.org/10.29039/2413-1873-2024-35-21-27.
Full textAbstract:
Experimental data are presented on changes in the compressive strength of heavy concrete using sulfate-resistant cement, Crimean aggregates and additives based on polycarboxylate ethers when kept in an aggressive environment - liquid from water treatment facilities in an urban-type settlement Gvardeiskoe, Simferopol district, Republic of Crimea. Compositions of heavy concrete have been developed using hyperplasticizing (polycarboxylate) additives that are capable of increasing their physical and mechanical characteristics over time when operating in aggressive environments. It is relevant to further develop the theoretical and experimental foundations for the production of cement concrete using the latest generation of superplasticizing additives based on polycarboxylates for wastewater treatment and recreational facilities. The durability of cement concrete is a key issue when using it in wastewater treatment and recreational facilities. Cement concrete can be susceptible to sulfate corrosion. Sulfates have a complex mechanism of action on the chemically active component of concrete - cement stone. Sulfates have a complex mechanism of action on the chemically active component of concrete - cement stone. The corrosive effect can increase or decrease depending on the concentration of aggressive components, with varying levels of exposure to salt solutions on the concrete structure, periodic drying, and partial immersion. This is due to the fact that the chemical processes of interaction between an aggressive environment and cement stone in concrete are influenced by physical processes of mass transfer of soluble components and crystallization of corrosion products or soluble components, which can accelerate or inhibit chemical processes. The parameters of the strength characteristics of the optimized compositions at different periods of strength gain have been established, and the average density and water resistance of the optimized concrete compositions have been established.
7
Plugin, Andrii, Olena Kaliuzhna, Olga Borziak, Oleksii Plugin, and Oleksandr Savchenko. "Ultrafast transfer strength of reinforced concrete sleepers by Using complex additives." Collected scientific works of Ukrainian State University of Railway Transport, no. 197 (December 22, 2021): 44–63. http://dx.doi.org/10.18664/1994-7852.197.2021.248243.
Full textAbstract:
The influence of superplasticizers-polycarboxylates and their complex additives withaccelerants - electrolytes and dispersion of calcium hydroxylates on the early strength of concretefor concrete of concrete sleepers has been studied. It was found that the use of superplasticizerspolycarboxylates can improve the early strength of the concrete after heat treatment, but eachadditive must be checked for consistency with the cement used. Approx Complex additives withaccelerators in conditions of natural hardening ensure an increase in the early strength of concrete,but some of them, which accelerate natural hardening, can reduce the strength after WWTP and mustbe checked before use. Electron-microscopic examinations of the structure of cement stone withadditives were carried out and it was found that the additive of only policarboxylate does not changethe structure of hydration products. Complex additives lead to formation of additional number ofcrystalline hydrates of AFm- and/or AFt-phases. The scheme of development of the cement hardeningprocess and the initial stage of cement hardening without or with additives has been developed. Bymeans of which the highest accelerating effect of the complex addition of polycarboxylate andcalcium hydroxylate dispersions was established by experimental investigations, Dispersion particlesincrease surface area where crystallization (condensation) of cement hydration products takes placeand ensures faster filling of spaces between cement particles (mineral additives) with them, fillers)with establishment of lances with electro-heterogeneous contacts. As a result of potentiodynamic andmicroscopic investigations it was established that the tested additives in the dosages do not causecorrosion effect on the steel reinforcement bars. Transmission strength values of 32 MPa for sleepersafter 24 years of hardening under low-heat regime and after 2 days of natural hardening have beenachieved. The formula for economic efficiency of using additives to reduce the energy intensity ofproduction of concrete sleepers has been proposed.
8
Qais, H., R. Bogdanov, N. Morozova, A. Mavlyuberdinov, and L. Suleymanova. "INFLUENCE OF SUPERPLASTIFYING ADDITIVES BASED ON POLYCARBOXYLATE ETHER ON THE TECHNOLOGICAL AND PHYSICAL-TECHNICAL PROPERTIES OF GYPSUM-CETMENT-POZZOLANIC BINDER." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 9, no. 8 (2024): 20–28. http://dx.doi.org/10.34031/2071-7318-2024-9-8-20-28.
Full textAbstract:
Effective modifiers of the structure and properties of concrete based on gypsum-cement-pozzolanic binder are chemical additives. Among a wide range of chemical additives, superplasticizing additives can be distinguished. The most effective in terms of water-reducing effect, increasing the mobility and strength of concrete based on gypsum-cement-pozzolanic binder are superplasticizers based on polycarboxylate ethers. The paper presents studies of the influence of superplasticizing additives on the physical and technical properties of gypsum-cement-pozzolanic binder based on low-grade gypsum and cement binders, and a binary active mineral additive consisting of zeolite-containing marl and microsilica. It has been shown that the introduction of the studied modifiers makes it possible to improve the performance properties of products based on gypsum-cement-pozzolanic binder, which is expressed in an increase in compressive strength and an increase in water resistance. Patterns of changes in water demand, setting time, and water-reducing effect of the gypsum-cement-pozzolanic binder mixture were obtained when it is modified with polycarboxylate additives of the following grades:“Melflux 2651 F”, “Polyplast type S”, “Polyplast type R”, “SPS-06”, “SPS-08”, “DK-100” and C-3 in comparison with unmodified HCPV, the change in strength with compression and softening coefficient of gypsum-cement-pozzolanic binder stone with these additives. It has been established that reducing the water requirement of the gypsum-cement-pozzolanic binder mixture by 60 % increases the compressive strength of gypsum-cement-pozzolanic binder stone samples by 33.5 MPa compared to the control composition. It has been shown that the most effective modifiers among those studied are “Polyplast type S” and “DK-100”.
9
Larsen, O. А., A. A. Solodov, and A. M. Bahrah. "Study of the influence of defoamers on the main properties of plasticized cement paste." Stroitel nye Materialy, no. 3 (March 15, 2025): 74–81. https://doi.org/10.31659/0585-430x-2025-833-3-74-81.
Full textAbstract:
The use of self-compacting concretes has become widespread in recent years. To achieve high flowability in mixtures, highly effective polycarboxylate based plasticizers are used. However, the use of superplasticizers in self-compacting concrete mixes without adding a defoamer can lead to a well-known problem: increased air entrainment and the formation of air bubbles. This can cause deterioration in the surface appearance. This article presents studies on the effects of various defoaming agents and air-entraining additives on the basic technological and rheological properties of plasticized by polycarboxylate plasticizers cement pastes, made from a blended binder which includes Portland cement and a microfiller based on ground blast-furnace granulated slag, in proportions of 25% and 40% respectively. The aim of this study was to investigate the spread diameter, expiration time, and dynamic viscosity of the cement paste with and without chemical additives, as well as to determine the type of defoaming agent that was most effective. The results of the experiments showed that a glycol ester-based defoamer was the most efficient. This type of agent reduced the number of surface pores in the paste. Optical microscopy was used to measure the size of these pores. It was found that glycol-ether defoamers were the most effective when used in concentrations of 0.02% and 0.04% in a cement mixture containing ground blast furnace slag (25%) and a polycarboxylate plasticizer. These additives changed the size and number of surface pores. It was also found that increasing the content of glycol-ether additives increased the mobility of the cement paste, but did not change the viscosity. There was a slight increase in average density and decrease in pore size and number by 0.28–0.29%, respectively. The study showed that using a defoaming agent in combination with a polycarboxylic acid ester-based additive can help reduce consumption and enhance plasticizing effects, thus predicting concrete behavior during construction.
10
Huang, Da Wei, Ren Juan Sun, Shan Shan Wei, Yi Zhang Hu, Yuan Yuan Wang, and Zhi Ge. "Influence of Additives to Cement Slurry Rheological Property." Applied Mechanics and Materials 651-653 (September 2014): 165–68. http://dx.doi.org/10.4028/www.scientific.net/amm.651-653.165.
Full textAbstract:
Adding different kinds of additives will change rheological properties of cement slurry, same to the concrete. The relationship between fluid shear stress (Γ) and the shear rate (Ds) called rheological properties. In this paper we studied the influence of different additives (Olyacryamide, polycarboxylate superplasticizer , nanoCaCO3) on the slurry rheological properties and the effects of polyacrylamide on cement mortar liquidity.
11
Pulyaev, I., and S. Pulyaev. "Experience of Using Self-Compacting Concrete Mixes in Transport Construction." Materials Science Forum 992 (May 2020): 135–42. http://dx.doi.org/10.4028/www.scientific.net/msf.992.135.
Full textAbstract:
The creation of self-compacting concrete (SCC) is associated with the introduction of plasticizing additives based on polycarboxylate esters (PCE). The first patent for a group of substances proposed for use as superplasticizers for concrete, was declared in the early 80-ies of the last century in Japan. In the mid 90-ies superplasticizers based on esters of polycarboxylates began to be used in Europe. In Russia, the use of self-compacting concrete began much later, and in bridge and tunnel construction almost a few years ago. Currently, in the European Union, 70-80% of reinforced concrete structures are made or erected from self-compacting concrete mixtures, and concrete is commonly called self-compacting. In Russia, such concretes are sometimes called self-leveling. The volume of their use is still small.
12
Kropyvnytska, Tetiana, Myroslav Sanytsky, and Oksana Rykhlitska. "The Effect of Pozzolanic Additives on the Performance of the Cementitious Matrix of Recycled Aggregate Concrete." Chemistry & Chemical Technology 18, no. 4 (2024): 592–600. https://doi.org/10.23939/chcht18.04.592.
Full textAbstract:
The article presents the influence of pozzolanic additives and polycarboxylate superplasticizer on the performance of the cementitious matrix of recycled aggregate concrete. The particle size distribution by volume and surface area of fly ash and silica fume is given, and the phase composition and microstructure of cementing paste are investigated.
13
Flores Yepes, José Antonio, Luis Miguel Serna Jara, Antonio Martínez Gabarrón, Ana María Codes Alcaraz, and Joaquín Julián Pastor Pérez. "Analysis of Additives in Gypsum Coatings Based on Melamine, Polycarbonate Salts, Polycarboxylate, and Polycarboxylic Acids." Coatings 11, no. 10 (2021): 1204. http://dx.doi.org/10.3390/coatings11101204.
Full textAbstract:
In this paper, we evaluate different gypsum coating additives that are available on the market, which are categorized by their chemical bases. The results will serve as a reference for future investigations of new additive bases in order to improve the properties of gypsum. As such, the objective of the this study is to assess the workability, mechanical behavior, and crystalline structure of calcium sulfate combined with different retarding and fluidifying bases, including melamine bases, which have a compressive strength of 19.32 N/mm2 and handling times with polycarbonate salts of up to 117.58 min. The following study presents the results of standard mechanical tests, analyzing semi-hydrated calcium sulfate (without additives) as a reference, along with the addition of melamines, synthetic melanin polymers, polycarbonate salts, polycarboxylates, and a polycarboxylic acid (citric acid). We already know that the addition of these additives will modify the mechanical properties of calcium sulfate, such as the Shore C surface hardness, flexural strength, modulus of elasticity, and compression resistance, which is the object of this study.
14
Rubio-Aguinaga, Andrea, José María Fernández, Íñigo Navarro-Blasco, and José Ignacio Álvarez. "Study on the Interaction of Polymeric Chemical Additives with Phase Change Materials in Air Lime Renders." Polymers 16, no. 8 (2024): 1121. http://dx.doi.org/10.3390/polym16081121.
Full textAbstract:
The interaction of microencapsulated phase change materials (PCMs) with polymeric chemical additives in an air lime binding matrix was studied. These polymer-based additives included an adhesion booster (derived from starch) and a superplasticizer (polycarboxylate ether). Two different PCMs with melting points of 18 °C and 24 °C were assayed. The microcapsules were composed of melamine, with paraffin-based PCM cores. Measurements of zeta potential, particle size distribution, adsorption isotherms, and viscosity analyses were performed to comprehend the behavior of the polymer-based additives within the air lime matrix and their compatibility with PCMs. Zeta potential experiments pointed to the absence of a strong interaction between the lime particles and the microcapsules of PCMs. At the alkaline pH of the lime mortar, the negative charge resulting from the deprotonation of the melamine shell of the microcapsules was shielded by cations, yielding high positive zeta potential values and stable dispersions of lime with PCMs. The polycarboxylate ether demonstrated the ability to counteract the increase in mixing water demand caused by the PCM addition in the lime matrix. The dispersing action of the superplasticizer on the lime particles was seen to exert a collateral dispersion of the PCMs. Conversely, despite the positive values of zeta potential, the addition of the starch-based additive resulted in the formation of large PCM-lime clumps. Air lime renders incorporating 5, 10, and 20% PCMs by weight with various dosages of these chemical additives were experimented with until the optimal formulation for the specific application of the mortars as renderings was achieved. This fine-tuned formulation effectively tackled issues commonly associated with the addition of PCMs to mortars, such as poor adhesion, crack formation, and reduced fluidity.
15
Смирнов, А. О., Л. М. Добшиц, С. Н. Анисимов та А. Ю. Лешканов. "Комплексное влияние добавок поликарбоксилатного суперпластификатора и микрокремнезёма на свойства самоуплотняющихся бетонов". ВЕСТНИК ПОВОЛЖСКОГО ГОСУДАРСТВЕННОГО ТЕХНОЛОГИЧЕСКОГО УНИВЕРСИТЕТА. СЕРИЯ: МАТЕРИАЛЫ. КОНСТРУКЦИИ. ТЕХНОЛОГИИ, № 2(30) (26 вересня 2024): 6–16. https://doi.org/10.25686/2542-114x.2024.2.6.
Full textAbstract:
Введение. В последние годы в современном монолитном строительстве широкое применение находят самоуплотняющиеся бетонные смеси, способные растекаться под действием собственного веса и заполнять густоармированные конструкции без уплотнения. Высокая однородность и стойкость самоуплотняющихся бетонных смесей к расслоению чаще всего достигается за счет увеличения расхода вяжущих материалов, что приводит к удорожанию бетонных смесей, а также к повышенной экзотермии и усадке бетонов. Для получения самоуплотняющихся бетонов с пониженным расходом цемента и высокими физико-механическими и эксплуатационными характеристиками требуется комплексное применение пластифицирующих и минеральных добавок, активно влияющих на реологические свойства бетонной смеси, структуру и фазовый состав цементного камня. В качестве таких добавок целесообразно использовать современные суперпластификаторы на основе поликарбоксилатных эфиров, а также высокодисперсные активные минеральные добавки, в частности микрокремнезём. Цель исследования – изучение комплексного влияния добавок поликарбоксилатного суперпластификатора и микрокремнезёма на свойства самоуплотняющихся бетонных смесей и бетонов. Материалы и методы. В качестве добавок применялись суперпластификатор на основе поликарбоксилатных эфиров Sika ViscoCrete 25 HE-C и микрокремнезём конденсированный неуплотненный МК-85 производства ПАО «НЛМК». Технологические свойства самоуплотняющихся бетонных смесей определялись в соответствии с ГОСТ Р 59715-2022, а физико-механические характеристики бетонов – ГОСТ 10180-2012 и ГОСТ 12730.4-2020. Результаты исследования. Установлено, что использование поликарбоксилатного суперпластификатора позволяет получить самоуплотняющиеся бетонные смеси с длительной сохраняемостью подвижности даже при низком значении водовяжущего отношения В/Вяж = 0,31. Применение высокодисперсного микрокремнезёма приводит к снижению водоотделения самоуплотняющихся бетонных смесей с поликарбоксилатным суперпластификатором и повышению их стойкости к расслоению. Комплексное использование добавок способствует повышению прочности самоуплотняющихся бетонов с поликарбоксилатным суперпластификатором на 23 % и снижению их капиллярной пористости на 47 %. Выводы.По результатам исследования разработаны самоуплотняющиеся бетонные смеси, обладающие высокой сегрегационной устойчивостью, повышенной текучестью с расплывом конуса более 700 мм, вязкостью 8 с и сохраняемостью подвижности более 3 часов в пределах марки по удобоукладываемости РК2, на основе которых получены высокопрочные бетоны с классом по прочности B70 при расходе цемента 500 кг/м3. Introduction. Nowadays, a lot of monolithic building is being done using self-compacting concrete mixtures, which can fill in heavily reinforced structures without compacting and flow under their own weight. High homogeneity and resistance of self-compacting concrete mixtures to stratification are most often achieved by increasing the consumption of binders, which leads to higher prices for concrete mixtures, as well as increased exothermy and shrinkage of concrete. Use of a thorough application of plasticising and mineral additives is required to produce self-compacting concrete with low cement consumption and high physical, mechanical, and operational characteristics. These additives influence the structure and phase composition of the cement stone as well as the rheological properties of the concrete mixture. Modern superplasticizers based on polycarboxylate esters and widely distributed active mineral additions, especially silica fume, are recommended as such additives. The aim of research is to investigate the complex effect of polycarboxylate superplasticizer and silica fume additives on the properties of self-compacting concrete and concrete mixtures. Materials and methods. The additives used were a superplasticizer based on polycarboxylate esters Sika ViscoCrete 25 HE-C and condensed uncompacted silica fume MK-85 produced by NLMK PJSC. The technological properties of self-compacting concrete mixtures were determined in accordance with GOST R 59715-2022, and the physical and mechanical characteristics of concrete were determined in accordance with GOST 10180-2012 and GOST 12730.4-2020. Research outcomes. The application of a polycarboxylate superplasticizer was discovered to enable the production of self-compacting concrete mixtures with long-term slump retention, even at low water-binder ratios (W/Binder = 0.31). When highly distributed silica fume is used in conjunction with polycarboxylate superplasticizer, self-compacting concrete mixtures show less water separation and exhibit a stronger resistance to stratification. The complex use of additives helps to increase the strength of self-compacting concrete with polycarboxylate superplasticizer by 23% and reduce their capillary porosity by 47 %. Conclusions. The research findings led to the development of self-compacting concrete mixtures with high segregation resistance, enhanced slump retention with a cone spread of more than 700 mm, a viscosity of 8 s, and 3-hour slump retention within the workability grade K2. These mixtures were then used to produce high-strength concretes with a strength class of B70 and a cement consumption of 500 kg/m3.
16
Amanda, Rosa Teixeira, Ferreira da Silva Brito Gabriel, de Paula Andréia, Machado Fabricio, and Henrique da Silva Rêgo João. "INTERACTION OF COMMERCIAL SUPERPLASTIFICANT ADDITIVES WITH POZOLANIC CEMENTS CONTAINING CALCINED CLAY." International Journal of Advances in Engineering & Technology 16, no. 6 (2023): 659–72. https://doi.org/10.5281/zenodo.10518192.
Full textAbstract:
<em>The utilization of polycarboxylate-based superplasticizer additives (PCE) in the concrete industry is widespread, and therefore, the dispersion mechanisms of these additives in cements containing supplementary cementitious materials (SCMs) present significant opportunities for investigation. This article aims to characterize the interaction between three commercial PCEs and three types of cement (pure Portland cement CPV-ARI and cement formulations containing 20 wt% and 28 wt% calcined clay content). The cement and calcined clay underwent physical-chemical characterization, whereas the PCEs were characterized through solid content determination and FTIR analysis. The interaction between cement, SCMs and additive was assessed by determining the optimal additive dosage using the mini-slump test, which was employed to evaluate its influence on kinetic mechanisms and hydration using a semi-adiabatic calorimeter, as well as mechanical strength. The PCEs exhibited high sensitivity to calcined clay, requiring higher dosages of PCEs to achieve the same fluidity compared to the system without clay.</em>
17
Grillo, Rodolfo H. F., Sylma Carvalho Maestrelli, K. V. F. Grillo, Neide Aparecida Mariano, Carolina del Roveri, and Patrícia Neves Mendes. "Study on the Influence of Water-Reducing Additives in Concretes for Civil Construction." Materials Science Forum 881 (November 2016): 233–38. http://dx.doi.org/10.4028/www.scientific.net/msf.881.233.
Full textAbstract:
Water-reducing additives for concretes are high efficiency dispersants that promote reduction of viscosity in suspensions, minimizing the amount of water used to hydrate the cement, thus enabling the fabrication of concrete with excellent properties. However, different forms of interaction between cement and additives are observed. In this work the properties of concrete formulated with three dosages of a polycarboxylate-based water-reducing additive and cement type CPII E-32 from two distinct manufacturers were investigated. In the experimental part, we verified the importance to use this technology justified by excellent results obtained for mechanical resistance and plasticity properties of the concretes. Through statistical analysis it was possible to point a discrete superiority in compositions using Holcim cement in function of its physical and chemical characteristics, in which the interaction process showed to be more efficient.
18
Trubitsyn, M., V. Lisnyak, L. Furda, N. Volovicheva, and E. Tarasenko. "DEFLOCCULATION OF HIGH ALUMINA MATRIX SYSTEMS WITH POLYCARBOXYLATE ETHER ADDITIVES." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 7, no. 7 (2022): 91–100. http://dx.doi.org/10.34031/2071-7318-2022-7-7-91-100.
Full textAbstract:
A comparative analysis of the effectiveness of the deflocculating effect of Russian and international polycarboxylate ethers additives on the rheological properties of high-alumina matrix suspensions is presented in this article. For the production of functional matrix systems, submicron activated α-alumina and modified high alumina cement are used in the ratio of 80:20 and 90:10 wt. %, respec-tively. A fluidity of matrix suspensions with a moisture content of 20% is carried out to assess the pres-ence of different deflocculants concentrations. All grades are manifested by rather high deflocculating effects in identifying high-alumina matrix suspensions. The best fluidity is recorded for matrix suspen-sions deflocculated with Cinteflow DUO 60 (0.38 %). A large influence on the expiration time is noted. Probability of thickening of matrix suspensions within 30 min. illumination is largely determined by the type and influence of the introduced deflocculants. The effect of deflocculating polycarboxylate ethers on spreadability has been studied. For certain casting mixtures with a moisture content of 12 %, the maximum diluting effect of using Sinteflow DM 50 (0.34 %). Deflocculants based on polycar-boxylate ethers produced by the Sintez OKA Group of Companies (Russia) show impressive efficiency compared to the complex deflocculant Peramin AL 200 and Peramin AL 300 (Kerneos, France).
19
Kalabina, Daria A., Grigorij I. Yakovlev, Zdenek Dufek, Grigoriy N. Pervushin, Kirill A. Bazhenov, and Viktoriya V. Troshkova. "FLUOROANHYDRITE COMPOSITIONS PLASTICIZED BY POLYCARBOXYLATE ESTERS." Engineering Structures and Technologies 11, no. 3 (2020): 101–5. http://dx.doi.org/10.3846/est.2019.11949.
Full textAbstract:
The influence of a plasticizer based on polycarboxylate esters on the properties of a high-strength fluoroanhydrite composition and a lightweight composition with expanded perlite sand is investigated. It was shown that the addition of 2% polycarboxylate esters on water base to compositions has increased compressive strength and a flexural strength up to 46% and 20% respectively compare to composite without any additives. Due to the structure’s compaction of the compositions, water absorption decreased and the water resistance of the material increased. Microstructural analysis of the compositions confirmed the improvement of physical and mechanical characteristics by changing the morphology of crystallohydrate formations, increasing the contact area between new formations and modifying the structure by carbon nanotubes. The developed mixtures are supposed to be apply for self-leveling fluid mixtures for floors with reduced thermal conductivity.
20
Zahia, Didouche, and Ezziane Karim. "Effect of cement fineness and polycarboxylate dosage on the rheological and mechanical behavior of a mortar." MATEC Web of Conferences 149 (2018): 01037. http://dx.doi.org/10.1051/matecconf/201814901037.
Full textAbstract:
The use of certain organic additives in the production of mortar and concrete influences the workability and the hydration kinetic of mortar. This results in a modification of some properties, namely rheological behavior and mechanical strength. The objective of this work is to evaluate the rheological and mechanical behavior of a mortar by varying the fineness of the cement and using the superplasticizer Polycarboxylate.
21
Guvalov, A. A., and S. İ. S.İ. "EFFECT OF ORGANIC AND FINE DISPERSER ADDITIONS ON RHEOLOGICAL PROPERTIES OF MINERAL SUSPENSIONS." Chemical Problems 18, no. 4 (2020): 469–76. http://dx.doi.org/10.32737/2221-8688-2020-4-469-476.
Full textAbstract:
In this study, the effect of mineral and organic additives on the properties of mineral suspensions was studied. Disperse mineral additives are used in cement systems to increase the amount of rheological matrix and ensure high fluidity. Due to the high dispersion of mineral additives, high-efficiency plasticizers were used to regulate the rheotechnological properties of cement-based mixtures. The effect of sulfonaphthalene-formaldehyde oligomer and polycarboxylate-based hyperplasticizers on the rheological properties of cement systems as a plasticizer was evaluated according to the methodology proposed by prof. V.I.Kalashnikov. Based on the results obtained, it was determined that limestone powder is more effective than other stone powders. As a result of the research, the optimal amounts of mineral additives and plasticizers were determined and the possibility of obtaining efficient, high-strength cement stone on their basis confirmed.
22
Sanytsky, Myroslav, Oleksandr Kotsii, Yuriy Bobetskyi, and Roman Kolodrub. "EFFECTS OF PLASTICIZING ADMIXTURES ON THE PERFORMANCE OF LOW-CARBON CONCRETES." Theory and Building Practice 2025, no. 1 (2025): 58–64. https://doi.org/10.23939/jtbp2025.01.058.
Full textAbstract:
The article presents research results on the influence of technological parameters on the technical and environmental characteristics of low-carbon ready-mix concretes. The study exam-ines the impact of aggregate gradation, cement content, lignosulfonate or polycarboxylate modifi-ers, and wet fly ash additives on concrete properties. The research demonstrates that clinker- and CO2-intensity indicators collectively determine the clinker efficiency of concrete. It was estab-lished that optimizing aggregate granulometry through the introduction of 2-5 mm crushed stone fraction in combination with a polycarboxylate superplasticizer contributes to the formation of a dense microstructure in the cementitious matrix. This approach ensures obtaining the specified concrete strength class with reduced cement consumption. The research confirms that the rational combination of technological factors affecting concrete mixtures opens prospects for creating modern low-carbon ready-mix concretes that meet sustainable development requirements.
23
Pushkarova, Kateryna, Maryna Sukhanevych, and Artur Martsikh. "Using of Untreated Carbon Nanotubes in Cement Compositions." Materials Science Forum 865 (August 2016): 6–11. http://dx.doi.org/10.4028/www.scientific.net/msf.865.6.
Full textAbstract:
One of the most important problem of concrete durability is increasing of waterproofing. Researches are devoted studying of cement mortars modified by carbon nanotubes, dispersed in plasticizers solutions. Were investigated physico-mechanical properties of cement paste, cement-sand mortar into which structure entered untreated carbon nanotubes (production of plant TM "Spetsmash" Kyiv, Ukraine) in various quantity. Were used as plasticizers in cement compositions additives substances of the various chemical nature – naphtaleneformaldehyde, melamineformaldehyde and polycarboxylate. Quantity of untreated nanotubes varied from 0,5%; 1,0% and to 1,5%. Concentration of additives was accepted taking into account recommendations of producers and made about 1% from the weight of cement. Were studied some technological processes of introduction untreated carbon nanotubes in cement system and is shown that the way of introduction of nanomodifiers has essential impact on strength characteristics of cementitious materials. Optimum decision introduction of untreated carbon nanotubes is using its in dispersion plasticizer of the working concentration prepared in an ultrasonic dispergator is established. Results of physico-mechanical tests of cement paste and cement-sand mortar showed positive influence at introduction of untreated carbon nanotubes as cement modifiers on strength characteristics of samples. Resalts is shown that the nanomodifier, used quantity about 1% in solution of lignosulfonate with polycarboxylate and melamineformaldehyde plasticizer has great impact on strength characteristics.
24
KATO, Hiroyoshi, Toyoaki MIYAGAWA, Akinori NAKAMURA, and Hiroyuki DOI. "Influence of Additives on Fluidity of Cement Paste with Polycarboxylate-Based Superplasticizers." Journal of the Society of Materials Science, Japan 52, no. 3 (2003): 294–300. http://dx.doi.org/10.2472/jsms.52.294.
Full text
25
Moharram, M. A., F. A. Saadalah, Nagwa Abdel-Hakeem, and O. M. Ibrahim. "Effect of certain additives on the physical properties of a polycarboxylate cement." Materials Research Bulletin 27, no. 1 (1992): 67–73. http://dx.doi.org/10.1016/0025-5408(92)90044-z.
Full text
26
Mordovtseva, M. V. "POSSIBILITIES FOR IMPROVING THE TECHNICAL CHARACTERISTICS OF CONCRETE BASED ON CEMENT WITH A LIMESTONE ADDITIVE." Bulletin of South Ural State University series "Construction Engineering and Architecture" 24, no. 4 (2024): 20–28. https://doi.org/10.14529/build240403.
Full textAbstract:
The article examines the influence of different amounts of limestone in cement and additionally introduced additives, microsilica and polycarboxylate superplasticizer, on the formation of the structure of cement stone and concrete and their technical characteristics. The study involved the analysis of the strength characteristics, porosity, porosity, elastic modulus of concrete samples and the phase composition of cement stone in concrete with various combinations of additives. The results demonstrate that the use of cement with 30% limestone without the addition of a super-plasticizer or a complex with microsilica will not provide the level of technical performance of concrete compared to cement containing up to 10% limestone. Attempts to compensate for this effect using highly effective additives such as superplasticizer and microsilica only help to maintain technical performance at the level of cement without limestone. As a result, the cement with a limestone content of up to 30% can only be used for interior work or for obtaining finishing compositions.
27
Belous, N. H., S. P. Rodtsevich, O. N. Opanasenko, and N. P. Krutko. "Influence of modifying additives on the structural characteristics and properties of portland cement concretes." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 57, no. 1 (2021): 94–100. http://dx.doi.org/10.29235/1561-8331-2021-57-1-94-100.
Full textAbstract:
The influence of polycarboxylate and naphthalene-sulfone superplasticizers, paraffin hydrophobizator and complex hydrophobic-plasticizing additives on the structural characteristics, physical-mechanical, hydrophysical properties, corrosion resistance and frost resistance of fine-grained Portland cement concretes was studied. Structural parameters of concretes (average and true density; density coefficient; total, open, closed porosity) were compared with compressive strength, water absorption, softening coefficients and salt resistance of materials. It is shown that the introduction of superplasticizers increases the density, softening coefficients and salt resistance, reduces the water absorption of Portland cement structures, and the use of paraffin hydrophobization and complex hydrophobic-plasticizing additives increases the closed porosity as a result of the formation of mosaic hydrophobic films on the surface of solid phases, which have a positive effect on the hydrophysical and physical-mechanical properties of concretes.
28
Talipov, Linar, and Evgeny Velichko. "Effect of polycarboxylate and polyarylate surfactants on corrosion of the steel reinforcement embedded in the concrete." MATEC Web of Conferences 251 (2018): 01026. http://dx.doi.org/10.1051/matecconf/201825101026.
Full textAbstract:
We considered the possibility to inhibit the corrosion of the steel reinforcement embedded in the concrete using different polymeric surfactants, when paired with the passivating and plasticizing chemical additives. Previously [1] the authors proposed the method to form the protective films on the surface of the steel reinforcement embedded in concrete using the polycomponent anticorrosion naphthalene sulfonate superplasticizer based additives. The results of further surveys provided in this article proved, that under the special conditions the polyarylate and polycarboxylate surfactants are capable to keep the steel reinforcement in the passive state in presence of chlorine ions. This is especially relevant, considering the fact, that the polymer additives intended for plasticization of concrete are more widely used for the manufacturing of the monolithic and prefabricated reinforced concrete structures. In the same time Deicing agents having in its composition chlorine ions, are widely used for deicing of roads in different countries. Chlorine ions adversely affect the reinforcement of concrete artificial structures in transport. the corrosion of metals incurs huge losses, the global cost is $ 2.5 trillion, equivalent to 3.4% of world gross domestic product (GDP) for 2013[2]. In 1993, the United States spent 20 billion dollars on the repair of reinforced concrete bridges only because of the impact of chlorides[3].
29
Khalikov, R. M., O. V. Ivanova, L. N. Korotkova, and D. A. Sinitsin. "Supramolecular impactmechanism of polycarboxylate superplasticizers on controlled hardening building nanocomposites." Nanotechnologies in Construction A Scientific Internet-Journal 12, no. 5 (2020): 250–55. http://dx.doi.org/10.15828/2075-8545-2020-12-5-250-255.
Full textAbstract:
Introduction. The use of modifying nano-additives in the production of binding building materials is one of the most effective ways to control the technological parameters of concrete by conducting good control of the rheological characteristics reliability. Plasticizing additives increase the water-holding capacity of building compositions, which leads to the dispersed nanosystems stability. This article is focused on examining the physical and chemical mechanisms of the supramolecular effects of polycarboxylate ethers on technological and rheological characteristics of cement nanobinders. Methods and materials. This study describes controlled hardening processes of concrete nanocompositions with demanded technological characteristics in the presence of highly effective plasticizers. Moreover, this paper carries out the analysis of the innovative trends in regulating the consistency of building nanocomposites with the use of new comb-like polycarboxylate esters, which as superplasticizers allow to purposefully influence the kinetics of structure formation of cement nanocomposites. Results. Electrostatic and steric repulsion mechanisms, as well as the dispersing effects of innovative and traditional plasticizing nanoparticles, affect the adsorption and diffusion layers of the hydrated cement nanobinders ultrastructure. The most effective plasticizing properties are shown by comb-like polycarboxylate esters (CPE) with a linear chain molecular weight of ≈12000 g/mol and a length of side branches which correspond to a molecular weight of ≈750 g/mol. The supramolecular mechanism of nanosteric van der Waals repulsive forces begins to be detected at a distance of ≈11 nm, and the elasticity of the lateral branches of innovative CPE is ≈ 5 nm. Individual segments of CPE macromolecules enter the diffuse layer of dispersed nanosystems due to lateral interactions of anions of functional groups, hydrophobic fragments, etc.; they enhance the plasticizing effect of cement binders in concrete nanocompositions. Discussion. When using superplasticizing CPE, the density of concrete nanocomposites can be increased by reducing the amount of water mass to the cement mass ratio to the optimal 0.3; at the same time, technological pumpability and reliability control of the joint hardening kinetics with fillers are preserved within the framework of the technological problems system solutionsconcept. Supramolecular interaction of «anchoring» functional groups of polyacrylic acid containing solid phase cations of cement microparticles, fractal clusters of calcium hydrosilicates and simultaneous steric stabilization of polyethylene glycol radicals give the necessary rheological characteristics to construction nanocompositions and allow the construction of high-strength 55÷80 MPa building materials. Conclusions. The branched comb-like nanostructure of polycarboxylate esters exhibits effective technological characteristics of superplasticizers for concrete, building mortars and dry building mixes
30
Jagadesh, P., K. Karthik, P. Kalaivani, et al. "Examining the Influence of Recycled Aggregates on the Fresh and Mechanical Characteristics of High-Strength Concrete: A Comprehensive Review." Sustainability 16, no. 20 (2024): 9052. http://dx.doi.org/10.3390/su16209052.
Full textAbstract:
This review examines the impact of recycled aggregates (RAs) on the fresh and mechanical properties of high-strength concrete (HSC). The results revealed that incorporating RAs can reduce the compressive strength of HSC by up to 25%, with strength values ranging from 40 to 70 MPa depending on the RA content. The addition of supplementary materials like silica fume, fly ash, and polycarboxylate ether significantly mitigated these negative effects, enhancing the compressive strength by approximately 15–20% compared with the control mixes without additives. Furthermore, the tensile strength was observed to decrease by up to 18% with increasing RA content, but fiber reinforcement improved this by 10%, demonstrating the potential of additives to offset mechanical weaknesses. The modulus of elasticity also declined by up to 30% with higher RA dosages, highlighting the critical impact of the adhered mortar quality on the overall stiffness of the concrete. According to the literature, it was noticed that, when the dosage of RCAs is increased, there is a drop in the strength activity index (SAI). When the substitute dosage exceeded 50%, the SAI decreased. These findings underscore the importance of using optimized additive combinations to improve the mechanical performance of RA concrete, making it a viable option for sustainable construction. Overall, the findings suggest that, although RAs may negatively affect certain physical traits of HSC, the use of appropriate additives can optimize its performance, making it a viable option for sustainable construction practices.
31
Pustovgar, Andrey P., Yury R. Krivoborodov, Aleksey O. Adamtsevich, et al. "The Impact of Plasticizers on the Nature of the Alkali-Silicate Corrosion in Cement Composites." Buildings 14, no. 1 (2024): 172. http://dx.doi.org/10.3390/buildings14010172.
Full textAbstract:
This research work attempts to reveal the mechanism of alkali corrosion in cement composites in the presence of plasticizers based on polycarboxylates (PCE), naphtha-lene-formaldehydes (SPNF), and lignosulfonates by maintaining a high pH of the liquid phase and additionally containing monovalent alkali earth metals in cement stone, as well as stopping this process by introducing an active mineral additive. ASR is studied by changing the relative strain with time according to ASTM C-1260. Deformation changes were confirmed by SEM and RFA studies of hydration products and ASR in the microstructure. Separate use of PCE plasticizers in the cement composition increases deformation by 50% to the 56th day; the use of SPNF increases deformation by 10% compared with the additive-free composition. The use of PLS reduces the relative deformation by 25%. The introduction of silica fume into cementitious composites containing plasticizers actually stops ASR only for a short time. A reduction in deformation during MC use together with plasticizer based on naphthalene sulfonate and polycarboxylate occurs only when the dosage of MS is increased to 20–30%; at a lower dosage, the effect is negative, which also affects the phase composition of the composites. The introduction of MC increases the value of the relative deformation compared with plasticizer compositions based only on PLS. SEM studies have detected microcracks and dense fine-crystalline silicate gel, which cause deformation changes in cement composite samples. Research has shown that concrete modified with SPNF and PCE at the maximum dosage of MC (30%) has minimal deformation rates and can be used to select optimal concrete compositions. The results of this study could help to minimize risks, prevent unacceptable expansion, and ensure the high quality of concrete and concrete products during their use as part of various nature-modifying additives.
32
Garabito, J., Lourdes Alameda, Jesús Gadea, and Sara Gutiérrez-González. "Influence of Superplasticizers on the Properties of Lightweight Mortar Plaster Made with Recycled Polymers." Advanced Materials Research 1129 (November 2015): 546–53. http://dx.doi.org/10.4028/www.scientific.net/amr.1129.546.
Full textAbstract:
The advantageous influence of two different polycarboxylate and melamine superplasticizers is studied in relation to the properties of blended mortar plaster made with recycled polymers (polyamide powder and polyurethane foam). The characteristics of the test specimens are defined and tested in both a fresh and a hardened state. The influence of the additives on the microstructure of the lightweight mortar plaster is defined through an analysis of the compatibility of the interface zone of the materials using Fast Scanning Electron Microscopy (FSEM).Our results show that the addition of additives influences the properties of the mortar plaster, enhances its mechanical properties, and increases its adherence with ceramic materials. These results confirm that superplasticizers (depending on the type and dosage) enhance both the properties of the mortar plasters produced with recycled polymers and the rheological properties of the mortars that include polyamide waste.
33
Pashkov, O. D., V. A. Ovechkina, A. A. Evgeniev, N. S. Lysenko, M. A. Pokrovsky, and A. L. Yurkov. "Vibrocasting of Silicon Carbide Based Concrete Materials." Journal of Material Science and Technology Research 11 (August 21, 2024): 25–34. http://dx.doi.org/10.31875/2410-4701.2024.11.04.
Full textAbstract:
In order to reduce the water demand of silicon carbide vibratory casting masses with high-alumina cement additives, the impact of various deflocculant of different natures to silicon carbide vibratory casting masses was investigated. The deflocculants used included polycarboxylate ether-based, sodium polyacrylate, high-molecular-weight poly-N-vinylpyrrolidone, and sodium salts of polymethylene-β-naphthalenesulfoxylic acid. Multifractional compositions of silicon carbide (2-3 mm, 1-2 mm, 0,5-1 mm, 0,2-0,5 mm, 0,063-0,12 mm fractions) with high-alumina cement and silicon additives, as well as with deflocculants, were studied. The firing of the materials was conducted in an oxygen atmosphere at temperatures between 1000 and 1400˚С. The adverse effect was demonstrated for deflocculant based on sodium polyacrylate and high-molecular-weight poly-N-vinylpyrrolidone, as the usage of these additives increases the water demand of the mix. A smaller amount of water used for the mass production allows the processing of more dense materials with reduced open and closed porosity. Using deflocculants, the moisture content of the material is reduced to 6.5%.
34
Mishutin, A. V., and L. Chintea. "THE EFFECT OF MODIFIED ADDITIVES ON STRENGTH AND FROST RESISTANCE IN FIBROUS CONCRETE OF RIGID ROAD PAVEMENTS." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 80 (September 3, 2020): 68–74. http://dx.doi.org/10.31650/2415-377x-2020-80-68-74.
Full textAbstract:
Abstract. The research is devoted to the development of compositions of modified fiber concrete of rigid road pavements with high strength and frost resistance through the use of metakaolin and a polycarboxylate type superplasticizer. The compressive strength, tensile strength under bending and frost resistance of concrete and fiber concrete of rigid road pavements were investigated according to the 4-factor optimal plan. In the experiment the amount of concrete components varied: Portland cement, polypropylene fibers, metakaolin, the polycarboxylate type additives Coral ExpertSuid-5. All mixtures had equal mobility P2 and their W/C depended on the composition of concrete. The use of polypropylene fiber and metakaolin necessitates an increase of W/C to maintain the mobility of the mixture. Increasing the amount of Coral ExpertSuid-5 additive in concrete to 0.9-1% allows to reduce significantly W/C of the mixture. Metakaolin as an active mineral additive increases the compressive strength and tensile strength of concrete. Rational in terms of increasing strength is the amount of metakaolin at the level of 20..22 kg/m3. With an increase in the amount of Coral ExpertSuid-5 additive to 0.9..1% due to a decrease of W/C, the compressive strength of concrete increases by 5..7 MPa, and the tensile strength increases by about 0.5 MPa. Due to the introduction of polypropylene fiber, the tensile strength of concrete in bending increases by 0.6..0.9 MPa. But dispersed reinforcement does not affect the compressive strength of concrete. The developed fiber concrete using a rational amount of modifiers, depending on the amount of Portland cement in the composition, has a compressive strength from 55 MPa to 70 MPa and tensile strength from 8 MPa to 9.5 MPa. The high strength of fiber-reinforced concretes allows their use in road pavements with the highest load. Frost resistance of concrete increases by 50 cycles or more when using fiber in an amount of 1.5-2 kg/m3. Due to the use of a rational amount of modifiers (0.8-1% Coral ExpertSuid-5 additive and 15-20 kg/m3 metakaolin), frost resistance of concrete and fiber concrete increases by 50-100 cycles. The developed modified fiber concretes of rigid road pavements depending on the amount of Portland cement in the composition have frost resistance from F350 to F450, which ensures their sufficient durability.
35
Matveeva, Larisa Yu, D. G. Letenko, and M. V. Mokrova. "Influence of Carbon Nanomodifier on the Structure and Properties of the Modified Gypsum Binder." Materials Science Forum 992 (May 2020): 233–37. http://dx.doi.org/10.4028/www.scientific.net/msf.992.233.
Full textAbstract:
Water-soluble polymer and latex additives are used to give the gypsum building plaster elasticity and placeability, improved water resistance and increased bending strength. The nanomodifiers in the form of carbon single-layer and multi-layer nanotubes, fullerenes and other nanoparticles are used for the formation of the structure of a gypsum stone with improved strength characteristics and improved weather resistance. In this work, the joint effect of the plasticizer based on polycarboxylate and the carbon nanomodifier on the structure, physicomechanical properties, and water resistance of the gypsum stone is investigated. It is shown that nanomodifiers contribute to the increase in the plasticizing ability of carboxylate additives, which leads to the significant decrease in the amount of mixing water, and as a result, to the increase in density, decrease in the porosity of the gypsum stone and the increase in its strength characteristics and water resistance.
36
Zhuang, Yan, Meng Wang, and Li Kun Zheng. "Experimental Study on Additives for the Reduction of Alkalinity for Ecological Concrete." Applied Mechanics and Materials 672-674 (October 2014): 1885–89. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1885.
Full textAbstract:
Concrete has been one of the most widely used materials in Engineering, which also induced the problems of vegetation destruction, soil erosion, and even deterioration for ecosystems. The ecological concrete was proposed to reinforce the slope due to its characteristics of high strength and large porosity to ensure the growth of plants. However the high alkalinity for ordinary portland cement constrained the growth of plants. An experimental test including 15 groups of samples was carried out to evaluate the effects of materials including polycarboxylate superplasticizer, calcium carbonate, ammonium bicarbonate, potassium dihydrogen phosphate, silica fume, ferrous sulfate and calcium lignosulfonate on pH value for ecological concrete. Under the condition that the compressive strength and porosity meet the requirement of ecological concrete, two sets of additives were proposed, which are suitable for the slope with high strength and the slope with low alkalinity requirements respectively.
37
Kazanskaya, Liliya, and Olga Smirnova. "Influence of mixture composition on fresh concrete workability for ballastless track slabs." E3S Web of Conferences 157 (2020): 06022. http://dx.doi.org/10.1051/e3sconf/202015706022.
Full textAbstract:
There are several factors that affect the fresh concrete workability: water demand and composition of Portland cement, properties of fine and coarse aggregates, presence of superplasticizer and others admixtures, etc. Influence of quantity and fineness of ground quartz additives as well as polycarboxylate-based superplasticizer amount on workability of fresh concrete was studied in the paper. The properties of fresh mixture (slump) and hardened concrete (compressive strength at the age of 24 hours, 28 and 360 days) were estimated. Enhancing the fresh concrete workability using fine ground quartz sand was stated. Savings of superplasticizer per 1 m3 of slab concrete and 1 km of the ballastless track were calculated.
38
Krivenko, Pavel V., Myroslav Sanytsky, and Tetiana Kropyvnytska. "The Effect of Nanosilica on the Early Strength of Alkali-Activated Portland Composite Cements." Solid State Phenomena 296 (August 2019): 21–26. http://dx.doi.org/10.4028/www.scientific.net/ssp.296.21.
Full textAbstract:
Significant reduction of carbon footprint of the construction industry is achieved through the use of composite Portland cements. However, substitution levels of additives in the composite cements are limited due to slow strength development arising from low reactivity of the pozzolana compared to clinker phases especially at the early age. The aim of the study was to evaluate effect of nanosilica on formation of strength properties and structure at the early age. The Portland composite cement containing clinker, granulated blast furnace slag, zeolite tuff as natural pozzolana and limestone with additives of nanosilica, Na2SO4 and polycarboxylate ether was investigated. The results obtained with the help of PSD, XRD, DTA, TG and SEM techniques showed that addition into the cement paste of the nanosilica particles with high surface reactivity improved the composite cement microstructure and leaching of calcium became significantly lower, because nanosilica particles react with calcium hydroxide with the formation of a denser C-S-H gel at the early age of hardening.
39
Sanytsky, Myroslav, Liudmyla Kripka, Тaras Kropyvnytskiy, and Nataliia Slаvych. "INFLUENCE OF TECHNOLOGICAL FACTORS ON CONCRETE EFFICIENCY INDICATORS." Theory and Building Practice 2024, no. 1 (2024): 86–91. http://dx.doi.org/10.23939/jtbp2024.01.086.
Full textAbstract:
The article presents the results of studies of the influence of technological factors (clinker factor of cements, grain composition of aggregates, cement consumption in concrete, modifier additives) on technical and environmental indicators of concrete efficiency. It has been shown that in combination, the parameters of clinker and CO2 intensities characterize the clinker efficiency of concrete, which can be improved by replacing part of the clinker in mixed cements with active mineral additives. Optimization of the granulometric composition of fine and coarse aggregates and the use of superplasticizers of the polycarboxylate type ensure the formation of a dense microstructure of the cementing matrix, which allows to increase the strength of concrete by 1-2 classes with an unchanged cement consumption and helps to reduce the CO2 emission rate. With the correct combination of various technological factors affecting concrete mixtures, a real opportunity is created to produce modern low-carbon concrete that meets the requirements of sustainability.
40
Akramov, Husniddin Akhrarovich, and Bakhtiyor Akhror ugli Makhsudov. "INVESTIGATION OF THE STRUCTURE OF CHEMICAL ADDITIVES AND THEIR EFFECT ON THE PROPERTIES OF CONCRETE AND CEMENT." Involta 1, no. 4 (2022): 357–64. https://doi.org/10.5281/zenodo.6390107.
Full textAbstract:
This article discusses chemical additives in modern concrete technology and their effects on concrete strength. The role of chemical additives and their importance in obtaining clear technical and economic efficiency and the strength of concrete structures are shown.
41
Pulyaev, I. S., O. V. Aleksandrova, S. M. Pulyaev, and A. S. Manyukov. "INFLUENCE OF ADDITIVES WITH VARIOUS ACTION SPECTRUM ON CONCRETE MIXTURE HEAT GENERATION IN TRANSPORT CONSTRUCTION." Вестник ВСГУТУ 3(94) (2024): 54–62. http://dx.doi.org/10.53980/24131997_2024_3_54.
Full textAbstract:
The article deals with topical issues of heat generation processes in concrete mixtures made with additives of various origins and action spectrums (mainly plasticizing and hyper plasticizing) in transport construction. They are widely used in recent years, as well as modifiers based on micro silica. The paper presents analysis of existing methods for determining the hydration heat of Portland cement. It demonstrates rationale principle scheme of the automated calorimetric unit, which gives the most accurate measurement results of changing compositions of concrete mixture and has found wide application in practice. The article demonstrates results of heat generation in concrete mixes based on cement binders prepared with plasticizers, a hyperactive plasticizer based on polycarboxylate and a concrete mix with the MB-10-01 modifier. The study shows expediency of such tests in approbation and implementation of high-grade concrete mixtures with modern additives. They have direct impact on the processes occurring in hardening concrete as well as the need to take into account the obtained data in process of designing and constructing transport infrastructure facilities for various purposes.
42
DURYTSKYI, Serhii, and Kateryna PUSHKAROVA. "Features of sulfate and carbonate activation of plasticized fly-ash cement binder systems." Transfer of innovative technologies 7, no. 2 (2025): 3–13. https://doi.org/10.32347/tit.2024.7.2.01.01.
Full textAbstract:
Abstract. The article is devoted to the study of the features of sulfate and carbonate activation of plasticized fly ash-cement binder systems In the course of research, the principles of composite build of plasticized ash-filled binding compositions containing 20-40% of OPC and coal by-product by increased operational characteristics have been proven. It is shown that the use of complex organo-mineral additives in fly ash-cement compositions, which contain a mixture of carbonate and sulfate compounds as a mineral component, and a plasticizing additive of the polycarboxylate type as an organic component, makes it possible to obtain an artificial stone that is not inferior in its properties to a stone obtained on the basis of additive-free cement type I. The peculiarities of the synthesis of the strength of artificial stone based on fly ash-cement compositions modified with an organo-mineral additive containing carbonate and sulfate mineral components were studied. It is shown that when only carbonate additives are used for modification, the formation of low-base calcium hydrosilicates takes place on its surface, and when sulfate and carbonate additives are simultaneously introduced, solid solutions based on ettringite and its carbonate analogue prevail among neoplasms. It has been confirmed that during the hydration of fly ash-cement binding systems activated by the addition of burnt gypsum stone, the greatest effect associated with the increase in strength at all stages of hardening is achieved when the additive is used in the amount of 10%. Modification of sand-cement compositions with a sulfate additive causes an increase in the strength of artificial stone at the age of: 2 days by 14.24; 25.0 and 35.47%; 7 days at 83.18; 43.6 and 40.6%; 28 days for 75.5; 41.6 and 31.5%, respectively, when used in the binder composition of cement 20; 30 and 40%. Modification of fly ash-cement compositions with a carbonate component causes an increase in the strength of artificial stone at the age of: 2 days by 18.6-20%; 7 days by 105.12-45.3%; 28 days by 86.6-30.0%, respectively. With a consumption of 40% OPC, the optimal amount of carbonate additive is 9% and causes an increase in the strength of artificial stone at the age of: 2 days by 33.3%; 7 days by 56.63%; 28 days for 43.5%.
43
Beldarrain, Sara, Guido Goracci, Jorge S. Dolado, Aitor Barquero, and Jose Ramon Leiza. "Poly(carboxylated ether)s as Cement Additives: The Effect of the Addition Method on Hydration Kinetics." Materials 17, no. 21 (2024): 5343. http://dx.doi.org/10.3390/ma17215343.
Full textAbstract:
Polycarboxylate ether (PCE) superplasticisers have been widely used in cement formulations. However, it is not until recently that several studies have analysed the relationship between the properties and the molecular structure. In the present work, PCEs with different side chain lengths and charge densities synthesised through free radical copolymerisation are used to analyse the effect they have on the hydration of ordinary Portland cement (OPC). It was found that the addition method of these PCEs to the OPC significantly affects the hydration kinetics of the cement paste. When PCEs are added through the direct addition method, a linear dependency between the retardation of hydration and the microstructure of the used PCEs is observed. On the contrary, when PCEs are added through the delayed addition method (PCEs are added to the cement paste 5 min after water), no retardation in hydration is observed, but the rate of hydration is reduced.
44
Абдраимов, И., Б. Копжасаров, Д. Ахметов, А. Алдунгарова, and А. Кисабаева. "EFFECT OF MODIFYING CHEMICAL ADDITIVES AND MICROSILICA ON THE STRENGTH GAIN KINETICS OF FHC." BULLETIN of D. Serikbayev EKTU 3 (September 30, 2023): 8–19. http://dx.doi.org/10.51885/1561-4212_2023_3_8.
Full textAbstract:
The article presents the results of studies of the possibility of accelerating the strength gain period of heavy concrete with the use of modern modifiers. The basic composition of fast-hardening concrete (FHB) of the class of average strength B25 was developed. Further, known methods and approaches were analyzed to accelerate hardening of BTB. Two main modifiers were chosen and a working hypothesis was adopted, which was to apply the method of mathematical planning of experiments in the search for an optimal and effective combination of microsilica and hyperplasticizer of the 2nd generation based on polycarboxylate esters. In the course of experiments by modeling the average strength values of samples in the early periods of hardening the optimum amount of chemical additive for obtaining high-quality bTB was deduced. The test results showed a real possibility of accelerating the hardening of BTB by 50% at the age of 2 days, a positive effect of accelerating the kinetics of strength gain and the possibility of saving the binder (cement) up to 20% when using microsilica.
45
Zhao, Y. Z., D. X. Du, and Y. H. Wang. "Preparation of silver nanoparticles and application in water-based conductive inks." International Journal of Modern Physics B 33, no. 32 (2019): 1950385. http://dx.doi.org/10.1142/s0217979219503855.
Full textAbstract:
We reported a simple, high yield and large-scale preparation method for silver nanoparticles. Silver nanoparticles with 8–13 nm in diameter were successfully synthesized by silver nitrate as raw material, sodium borohydride as reducing agent, dispersan-5040 (polycarboxylate sodium salt) as surface modifier in aqueous solution. The effects of sodium borohydride and dispersan-5040 on the morphologies of silver nanoparticles were investigated. Further, the conductive inks were prepared with as-synthesized silver nanoparticles as conductive fillers in the presence of deionized (DI) water and additives. The effects of conductive fillers and additives on the pH, conductivity, surface tension and viscosity of the inks were investigated. The conductive patterns were fabricated by inkjet printer and their performances were studied. The sheet resistances of the printed pattern with seven-layer was 1.2 [Formula: see text] when the printed pattern was heat-treated at 120[Formula: see text]C for 60 min. We succeeded in printing a simple conductive circuit on photographic paper, which can light three 0.06 W LED beads. The successful fabrication of the functional circuit proves the feasibility of the ink and provides some ideas for future paper-based circuits.
46
Mukhametrakhimov, R. Kh. "INVESTIGATION OF PLASTICIZING ADDITIVES BASED ON POLYCARBOXYLATE ESTERS ON THE PROPERTIES OF CONCRETES FORMED BY 3D PRINTING." Construction Materials and Products 5, no. 5 (2022): 42–58. http://dx.doi.org/10.58224/2618-7183-2022-5-5-42-58.
Full text
47
Marushchak, Uliana, Myroslav Sanytsky, Nazar Sydor, and Serhii Braichenko. "Research of impact resistance of nanomodified fiberreinforced concrete." MATEC Web of Conferences 230 (2018): 03012. http://dx.doi.org/10.1051/matecconf/201823003012.
Full textAbstract:
Effects of multilevel modification of concrete structure with complex nanomodifier at nano- and microlevel and polypropylene fiber at macro- and mesolevel on mechanical properties and impact resistance of concrete are presented. Nanomodification with complex nanomodifier, which consists of polycarboxylate ether superplasticizer, ultra- and nanofine mineral additives, provides early structure formation, higher strength at early and later ages. The increasing of the static hardness according to Brinell and Mayer of the nanomodified concrete was indicated the high energy of the bond between the structural elements in the surface layer of nanomodified concrete, as well as the ability of the structure to withstand elastic and plastic deformations under uneven compression load. Incorporating of polypropylene fibre to concrete was increased the impact resistance according to parameter of first crack strength and failure energy and changed the failure pattern from brittle to ductile mode.
48
Pan, Tinghong, Yaqing Jiang, Hui He, Yu Wang, and Kangting Yin. "Effect of Structural Build-Up on Interlayer Bond Strength of 3D Printed Cement Mortars." Materials 14, no. 2 (2021): 236. http://dx.doi.org/10.3390/ma14020236.
Full textAbstract:
Understanding the relationship between the intrinsic characteristics of materials (such as rheological properties and structural build-up) and printability and controlling intrinsic characteristics of materials through additives to achieve excellent printability is vital in digital concrete additive manufacturing. This paper aims at studying the effects of material’s structural build-up on the interlayer bond strength of 3DPC with different time gaps. Structural build-up can indirectly affect the interlayer bond strength by affecting the surface moisture of concrete. Based on the structural build-up of 3DPC, a new parameter, maximum operational time (MOT), is proposed, which can be considered as the limit of time gap to ensure high interlayer bond strength. Slump-retaining polycarboxylate superplasticizer (TS) slightly slows down the physical flocculation rate, but increases the maximum operational time of the cement paste. Nano clay significantly increases the sort-term structural build-up rate and has the function of internal curing and water retaining. Composite with nano-clay and TS can reduce the loss of surface moisture of 3D printed layers, prevent the formation of interface weak layer, and increase the interlayer bond strength between printed layers. This contribution can provide new insight into the design of 3D-printed ink with good extrudability, outstanding buildability, and excellent interlayer bond strength.
49
Stankiewicz, Natalia, and Michał Bołtryk. "Thin Protective Layers Made out of Special Concretes." Solid State Phenomena 259 (May 2017): 101–5. http://dx.doi.org/10.4028/www.scientific.net/ssp.259.101.
Full textAbstract:
All concrete and reinforced concrete engineering structures degrade over time when they are exposed to the surrounding environment. In particular, the concrete protective layer of reinforcing steel is rapidly degraded, which can lead to failure of the structure. Adequate durability of concrete coatings must be taken into consideration. This property can be ensured by modifying the composition of the concrete mix. This can be done through the implementation of appropriate admixtures and additives into cement composites. This modification, called material and structural protection, can be used in the form of thin protective layers (TPL). They are intended to protect an ordinary concrete from external aggressions. Thin protective layers made out of special concrete will be presented in the article. The impact of three different thicknesses of protective layers on properties of cement composites was investigated. Special concrete was modified with silica fume, crushed granite aggregate and superplasticizer based on polycarboxylate. Thin protective layers are characterized by very good water resistance and resistance to freezing and thawing. The layer of special concrete with increased durability due to the reduced water/cement ratio, high cement content and by using additives and admixtures, should fully protect ordinary concrete against the negative influence of the aggressive environment.
50
Sinyakin, Anatoliy, Dmytro Rozmus, Vita Hurkalenko, Oleksii Kabus, and Oleksii Hunyak. "The effect of admixtures on hydration kinetics, shrinkage, and strength of HPC." IOP Conference Series: Earth and Environmental Science 1376, no. 1 (2024): 012022. http://dx.doi.org/10.1088/1755-1315/1376/1/012022.
Full textAbstract:
Abstract The paper investigates the impact of admixtures on the properties of high-performance concrete (HPC). A series of test were conducted to evaluate the influence of the studied additives and their combinations on drying and autogenous shrinkage, thermal kinetics and strength of cement pastes, mortars and concretes. It is shown, that replacing part of the cement with silica fume has no significant impact on drying shrinkage. The study demonstrates that polycarboxylate-based superplasticizer and shrinkage reducing admixture (SRA) containing neopentyl glycol enhance fresh concrete workability, produce hardened concrete with high strength and durability, and reduce early-age shrinkage in HPC by up to 3 times. The findings reveal that the use of SRA admixture provides a stable effect only at a dosage above 1 wt.% in HPC, where the amount of binder significantly affects drying shrinkage. Results indicate, that combined action of 1.5% of SRA and 0.6 kg/m3 of polypropylene microfibers allows to obtain 40% lower drying shrinkage compared to non-modified HPC.