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1
Lam, Nguyen Ngoc. "Some microstructure properties at early age of ettringite binder based on rich C12A7 calcium aluminate cement." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 12, no. 3 (April 30, 2018): 44–50. http://dx.doi.org/10.31814/stce.nuce2018-12(3)-05.
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The mineral composition of calcium aluminate cements is traditionally based on CA (monocalcium aluminate-CaO·Al2O3). Recently, a new cement with the main compound of C12A7 (Mayenite) has been developed for rapid hardening binder. This cement is used in conjunction with a sulfate binder to form a new type binder called ettringite binder due to the high quantity of ettringite in the hydration product, opened new possibilities for mortar and concrete formulations. This paper focuses on some microstructure characteristics of the ettringite binder based on a C12A7 rich cement and a hemihydrate at early age. Some important characteristics of this binder were found, such as: short setting time (about 40–50 minutes), rapid expansion just after initial setting time, rapid evolution of porosity and bound water during the first 5 hours of hydration. The correlation between bound water and porosity of hardened binders was also found in this paper.
Article history: Received 24 January 2018, Revised 04 April 2018, Accepted 27 April 2018
2
Chakrabarti, Srijib, and Jayantha Kodikara. "Basaltic Crushed Rock Stabilized with Cementitious Additives: Compressive Strength and Stiffness, Drying Shrinkage, and Capillary Flow Characteristics." Transportation Research Record: Journal of the Transportation Research Board 1819, no. 1 (January 2003): 18–26. http://dx.doi.org/10.3141/1819b-03.
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Research was undertaken to increase knowledge of the properties of local stabilized pavement materials to facilitate their wider use in road construction and rehabilitation. Laboratory tests involved testing for the unconfined compressive strength (UCS), shrinkage, and capillary behavior of crushed basaltic rocks stabilized with two conventional cementitious binders—general purpose cement and lime—and two cementitious binders comprising industrial waste products—blended cement and alkali-activated slag. The alkali-activated slag and blended cement significantly increased UCS of untreated material and performed as well as or better than such traditional binders as general purpose cement. Overall, lime performed poorly as a stabilizer of crushed basaltic rocks, primarily because the fine content containing clay minerals was not significant in the crushed basaltic rock composition. UCS of stabilized materials increased significantly as binder content increased; UCS could be described as a function of binder quantity. Ultimate shrinkage increased with binder content for general purpose cement and alkali-activated slag, but for blended cement, behavior was different. The rate of drying shrinkage was relatively high at the early stage of shrinkage. Generally, alkali-activated slag produced less shrinkage compared with general purpose and blended cements. Capillary rise and water absorption were also measured. Test results indicated that the rate of capillary rise and amount of water absorbed by the material matrix decreased with the increase of binder content. The research indicated that the use of binders with industrial by-products could be a viable option in stabilization of crushed basaltic rock materials.
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Kaddo, Maria. "Possibilities of using aluminate cements in high-rise construction." E3S Web of Conferences 33 (2018): 02056. http://dx.doi.org/10.1051/e3sconf/20183302056.
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The article describes preferable ways of usage of alternative binders for high-rise construction based on aluminate cements. Possible areas of rational use of aluminate cements with the purpose of increasing the service life of materials and the adequacy of the durability of materials with the required durability of the building are analyzed. The results of the structure, shrinkage and physical and mechanical properties of concrete obtained from dry mixes on the base of aluminate cements for self-leveling floors are presented. To study the shrinkage mechanism of curing binders and to evaluate the role of evaporation of water in the development of shrinkage was undertaken experiment with simple unfilled systems: gypsum binder, portland cement and «corrosion resistant high alumina cement + gypsum». Principle possibility of binder with compensated shrinkage based on aluminate cement, gypsum and modern superplasticizers was defined, as well as cracking resistance and corrosion resistance provide durability of the composition.
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Kharchenko, Alexey I., Vyacheslav A. Alekseev, Igor Ya Kharchenko, and Andrey A. Alekseev. "Application of slag-alkali binders in jet cement grouting for soil consolidation." Vestnik MGSU, no. 6 (June 2019): 680–89. http://dx.doi.org/10.22227/1997-0935.2019.6.680-689.
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Introduction. The study proves actuality of the problem connected with obtaining efficient slag-alkali binders for usage in soil jet cement grouting. Replacement of usual portland cement for a slag-alkali binder in geotechnical underground construction activities allows solving a problem of waste (slag) utilization and increase economic efficiency of the soil jet cement grouting. In view of cement grouting technology features and possibility of usage cementation mixtures with various engineering characteristics for different soil types, a broad nomenclature of slag-alkali compositions can be used for obtaining soil-concrete structures. Materials and methods. Different types of slag were studied as constituents of composite binders. The PTs 500 D0 cement was taken as the basic portland cement. Standard requirements for cementation mixtures of mixing and pump facilities for soil-concrete bodies became the criteria. Investigations of hydration and structure formation during hardening of slag-alkali binders and soil-concretes on their base were conducted using a system of physical and chemical methods. Evaluation of construction and engineering properties of the composite slag-alkali binder was accomplished in accordance with the methods as per GOST 10181-2014 and GOST 5802-86 state standards. Results. Results of analysis how the slag type and amount influence the physical and mechanical properties of the binder used for jet soil cementation are presented. The article shows improvement of physical, mechanical, process and usage properties of the slag-alkali binder. General mechanism of impact of the slag on properties of the cementation mixture were revealed. Conclusions. Efficiency of application of the slag as an active component of the composite binder for jet cementation in geotechnical construction was theoretically substantiated and experimentally demonstrated. General applicability of the obtained concrete mixture based on the slag-alkali binder is stated for usage in cementation methods of improvement of technical parameters of concrete mixture and concretes. A classification of expanding cements possessing various expansion degrees was suggested for solving different construction problems.
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Wong, John Kok Hee, Sien Ti Kok, and Soon Yee Wong. "Fibers, Geopolymers, Nano and Alkali-Activated Materials for Deep Soil Mix Binders." Civil Engineering Journal 6, no. 4 (April 1, 2020): 830–47. http://dx.doi.org/10.28991/cej-2020-03091511.
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Ordinary Portland Cement (OPC) and Lime (CaO) have traditionally been used as binder materials for Deep Soil Mix (DSM) ground improvement. Research has been conducted into possible alternatives such as pozzolans to reduce reliance on either cement or lime. However, pozzolans still undergo similar calcium-based reactions in the strengthening process. In this review, further alternative binder materials for soil strength development are explored. These recent developments include fiber reinforcement materials, alkali activation methods, nanomaterials and geopolymers, which can potentially achieve equal or improved performance. Research to date has shown that alkali-activated materials and geopolymers can be equivalent or superior alternatives to pozzolanic supplemented cement binders. The case is made for GP cements which potentially produces 80% less CO2 than conventional portland cement during manufacture. One-part AAM and GP cements are a promising substitute for portland cement in DSM. A combined approach which incorporates both Ca and alkali activated/geopolymer types of materials and hence reactions is proposed.
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Owsiak, Zdzisława, Przemysław Czapik, and Justyna Zapała-Sławeta. "Properties of a Three-Component Mineral Road Binder for Deep-Cold Recycling Technology." Materials 13, no. 16 (August 13, 2020): 3585. http://dx.doi.org/10.3390/ma13163585.
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This study examined the physical properties of a three-component mineral binder that is typically used in deep-cold recycling. Test binders were produced using Portland cement, hydrated lime, and cement bypass dust (CBPD) as a byproduct derived from cement production. The suitability of CBPD for use in road binders was assessed. Effects of the three-component binder composition on the setting time, soundness, consistency, and tensile and compressive strengths of the cement pastes and mortars were determined. The pastes and mortars of the same consistency obtained at different w/b ratios were tested. On this basis, the mixture proportions resulting in road binders satisfying the requirements of PN-EN 13282-2:2015 were determined. By mixing cement, lime, and CBPD during the tests, binder classes N1 to N3 were obtained. The replacement of 40% of cement mass with the CBPD high in free lime produced road binders suitable for recycled base layers. The total content of CBPD and hydrated lime in the road binder should not exceed 50% by mass. The potential risk of mortar strength reduction due to KCl recrystallization was discussed.
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Potapova, Ekaterina, Aung Kyaw Nyein, Elena Tsvetkova, and Hans-Betram Fischer. "Modification of the structure of gypsum-cement-pozzolanic binder." MATEC Web of Conferences 329 (2020): 04007. http://dx.doi.org/10.1051/matecconf/202032904007.
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Modification of the structure of gypsum-cement-pozzolan binder allows you to expand the range of gypsum binders for creating dry building mixes and structural elements of low-rise buildings. It was found that in the presence of functional additives, the character of crystallization of hydrate neoplasms changes, which leads to a change in the properties of the hardened binder. The study of the effect of individual and complex additives on the properties of gypsum-cement-pozzolan binder allowed us to develop water-resistant gypsum binders.
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Emmanuel, Opara Uchechukwu, Aldi Kuqo, and Carsten Mai. "Non-conventional mineral binder-bonded lignocellulosic composite materials: A review." BioResources 16, no. 2 (April 22, 2021): 4606–48. http://dx.doi.org/10.15376/biores.16.2.emmanuel.
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The construction industry suffers from unsustainability and contributes more than any other industrial sector to carbon emissions that lead to global warming. Increasing economic and environmental concerns related to conventional energy- and CO2-intensive building materials have propelled the rapid and sustained expansion of research in the area of plant-based inorganic mineral binder-bonded materials for the construction industry. The resulting composites can be qualified as eco-responsible, sustainable, and efficient multifunctional building materials. So far, most of these research efforts have not received as much attention as materials based on ordinary Portland cement (OPC). To address this gap, this review focuses on mineral binder-based lignocellulosic composites made from non-conventional inorganic mineral binders/ cements with low embodied energy and low carbon footprint, namely hydrated lime-based binders, magnesium-based cement, alkali-activated cement, and geopolymers, as sustainable alternatives to OPC-bonded lignocellulosic composites (state-of-the-art). The emphasis here is on the application potentials, the influence of production parameters on the material properties/ performance, and recent advancement in this field. Finally, a prediction is provided of future trends for these non-conventional mineral binder-bonded lignocellulosic composites.
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Dvorkin, Leonid, Nataliya Lushnikova, and Mohammed Sonebi. "Application areas of phosphogypsum in production of mineral binders and composites based on them: a review of research results." MATEC Web of Conferences 149 (2018): 01012. http://dx.doi.org/10.1051/matecconf/201814901012.
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The increase of the consumption of gypsum products in construction industry with a limited amount of natural gypsum deposits requires alternative sources of gypsum-containing raw materials. In some countries which have fertilizers industry plants, the problem can be solved using industrial wastes, e.g. phosphorgypsum – a byproduct of fertilizers’ production. Kept in dumps over decades, phosphorgypsum is subjected to the chemical changes due to washing out impurities with rain and other natural factors. However, there are observed deviations of harmful impurities in dumped PG depending on its age., Phosphorgypsum of any age requires chemical treatment to neutralize remains of phosphorus and sulfuric acids, fluorine compounds. According to our researches one of the most simple and effective method of neutralization the impurities is using lime-containing admixtures. The paper presents results of laboratory tests of phosphorgypsum as a component of clinker and non-clinker binders. There were investigated the impact of phosphorgypsum as admixture for clinker binders to substitute natural gypsum. Neutralized phosphorgypsum can be applied as mineralizing admixture in calcination of Portland cement clinker. Adding 2 to 2.5% of phosphorgypsum as setting time regulator resulted in a similar physical and mechanical properties compared to mix made with natural gypsum. Another important area of phosphorgypsum application is sulphate activatoion of low-clinker blast-furnace slag cement (clinker content is less than 19%). According to results, the incorporation of phosphorgypsum as sulphate activator in cement has the better effect as natural gypsum. Other development has been carried out to modify the phosphorgypsum binder properties. Complex additive consisted of polycarboxylate-based superplasticizer and slaked lime permitted an increase mechanical properties of hardened phosphorgypsum binder due to significant a reduction of water consumption. Such modified binder can be used as partial or complete replacement of gypsum binder for filling cements and finishing plasters. It can substitute gypsum in non-clinker binders like supersulphated cements. There were also developed compositions of supersulphated cements based on low-alumina blast furnace slag and phosphorgypsum. Supersulphated cements were tested in normal-weight and light-weight concrete.
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Chang, Ilhan, Minkyung Jeon, and Gye-Chun Cho. "Application of Microbial Biopolymers as an Alternative Construction Binder for Earth Buildings in Underdeveloped Countries." International Journal of Polymer Science 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/326745.
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Earth buildings are still a common type of residence for one-third of the world’s population. However, these buildings are not durable or resistant against earthquakes and floods, and this amplifies their potential harm to humans. Earthen construction without soil binders (e.g., cement) is known to result in poor strength and durability performance of earth buildings. Failure to use construction binders is related to the imbalance in binder prices in different countries. In particular, the price of cement in Africa, Middle East, and Southwest Asia countries is extremely high relative to the global trend of consumer goods and accounts for the limited usage of cement in those regions. Moreover, environmental concerns regarding cement usage have recently risen due to high CO2emissions. Meanwhile, biopolymers have been introduced as an alternative binder for soil strengthening. Previous studies and feasibility attempts in this area show that the mechanical properties (i.e., compressive strength) of biopolymer mixed soil blocks (i.e, both 1% xanthan gum and 1% gellan gum) satisfied the international criteria for binders used in earthen structures. Economic and market analyses have demonstrated that the biopolymer binder has high potential as a self-sufficient local construction binder for earth buildings where the usage of ordinary cement is restricted.
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Panek, Rafał, Magdalena Wdowin, Lidia Bandura, Ewa Wisła-Walsh, Paweł Gara, and Wojciech Franus. "Changes in the Textural Parameters of Fly Ash-Derived Na-P1 Zeolite During Compaction Processes." Mineralogia 48, no. 1-4 (December 1, 2017): 3–22. http://dx.doi.org/10.1515/mipo-2017-0008.
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Abstract This paper presents the possibility of receiving the granular forms of a zeolitic material of the Na-P1 type obtained from high-calcium fly ash in a semi-technical scale by means of three compacting techniques. The compaction process was carried out using cement, molasses and water glass as binders. Each of the proposed compacting methods affected the textural parameters of the obtained granular zeolite forms, as well as the binders used. In comparison to the other binders it was found that the cement binder had the smaller impact on the values of the textural parameters of the obtained compacted zeolite forms. The surface area for the zeolite Na-P1 was 98.49 m2·g-1, for the cement as a binder was 69.23 m2·g-1, for the molasses was 52.70 m2·g-1and for the water glass was 40.87 m2·g-1. For this reason, the briquetting and extruding tests were carried out using cement as a binder.
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Xu, Li Wei, and Jian Lan Zheng. "Influence of the Fly-Ash Content of Concrete at Low Water-Binder Ratio on Hydration Degree of Binders and Cement." Advanced Materials Research 250-253 (May 2011): 445–49. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.445.
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The hydration degree of binders and cement is investigated by measuring the adiabatic- temperature rise of concrete at low water-binder ratio with different fly-ash content. The results denote that, with a constant water-binder ratio, both of the hydration degree of binders and that of cement decrease with the increasing fly-ash content in the early stage. In a later stage, however, the hydration degree of cement increases with the increasing fly-ash content and the hydration degree of binders peaks when the fly-ash content is 35%. Fly ash is one of the mineral admixture of which high-performance concrete is made up. It brings down the rise of concrete temperature significantly and helps solve the problems of shrinkage and crack of concrete structure. Because the hydration mechanism in common concrete is different from that in concrete with low water-binder ratio, and the hydration environment is different between concrete and cement pastes, to determine the adiabatic-temperature rise of concrete directly conforms to the actual situation. The adiabatic-temperature rise, adiabatic-temperature-rise rate, hydration degree of both binders and cement are investigated by measuring adiabatic-temperature rise of concrete with different fly-ash content.
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Kazragis, Algimantas, Aušra Juknevičiūte, and Albinas Gailius. "UTILIZATION OF BOON AND CHAFF FOR MANUFACTURING LIGHTWEIGHT WALLING MATERIALS." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 12, no. 1 (March 31, 2004): 12–21. http://dx.doi.org/10.3846/16486897.2004.9636810.
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Lightweight composites for walls and thermal insulation, containing anhydrite (An) or aluminate cement (Al), vinyl acetate (VA) or cellulose (Cl) polymeric binders and cellulose fiber fillers (boon, chaff) were produced. The best results were obtained for transportation and construction of items containing: An ≥ 30–45 %, Al ≥ 30–50 %, VA ≥ 1–5 %, Cl ≥ 0,5–5,0 %, boon or chaff ≥ 40–47 %. Polymeric binder VA for both kinds of cement is better than Cl. An is better for boon than for chaff. Aluminate cement is a good binder for both types of fiber fillers. Density r of a composite containing cements 50–60 % is less than 400 kg/m3. According to density such composite materials are light‐weight heat‐insulating materials. Density (p ≤ kg/m3) depends on the amount of cement content. Bending strength for samples with p ≤ 400 kg/m3, containing CMC is 0,6–1,3 MPa. Coefficient of thermal conductivity for samples, density with 400 kg/m3 is 0,06 W/m‐K.
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Khroustalev, B. M., U. A. Veranko, V. V. Zankavich, Yu G. Aliakseyeu, Yue Xuejun, Bo Shang, and Jicun Shi. "Structure Formation and Properties of Concrete Based on Organic Hydraulic Binders." Science & Technique 19, no. 3 (June 5, 2020): 181–94. http://dx.doi.org/10.21122/2227-1031-2020-19-3-181-194.
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The article addresses the issues of structure formation of road composite materials containing hydraulic (рortland cement) and organic (bitumen) binders. It has been determined that organic and hydraulic binders, being thermodynamically incompatible, are capable of interaction and complement each other. Structure formation processes are associated with interphase transition layers interaction mechanism and the direct formation of phase contacts with cement crystallohydrates. The interphase boundary is diffuse and is established through interphase transition layers. The emergence of interfacial layers is thermodynamically advantageous, since it contributes to a decrease in Gibbs free energy and does not contradict modern concepts of solid state physics. It was established that with cement content of about 30 % of complex bitumen-cement binder volume, there will appear (nucleate) phase contacts that will prevail in the binder structure when the cement content is more than 60 %. In the case phase contacts prevail, concrete will demonstrate significant strength at high temperatures, but low temperature and fatigue crack resistance, which will lead to their durability loss. The cement content of 30–40 % of the total complex binder can be considered optimal.
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Gomes, Carlos Eduardo Marmorato. "Alternative Binder for Fibercement Building Materials." Advanced Materials Research 753-755 (August 2013): 616–22. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.616.
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This paper shows results of some properties of Magnesium oxysulfates (MOS) reinforced by fibers, specially the modulus of rupture (MOR) and durability. As showed by the literature [7], It is known that MOS cement can be formulated by the reaction between magnesium oxide and magnesium sulfate solution and like that of magnesium oxychloride (MOC) has very good binding properties. The resistance of MOS cements to abrasion is about 1.5 times that of Portland cement, but only 50% that of MOC cement. Its compressive and transverse strengths are superior to Portland cement but not as good as MOC cement. In this way, the authors formulated different matrices of MOS cement reinforced by polymeric and cellulose fibers. Also, calcium carbonate was employed. The results showed to be possible the use of MOS fibercements as an alternative for non-asbestos products such as panels and roofing elements besides the effective reduction of CO2 emission to atmosphere.
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Staněk, Theodor. "Waste Diatomaceous Earth as Cementitious Binder Constituent." Materials Science Forum 865 (August 2016): 1–5. http://dx.doi.org/10.4028/www.scientific.net/msf.865.1.
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Paper is aimed at study of preparation possibilities of cementitious binders with waste diatomaceous earth. In the first step, the influence of ground diatomaceous earth on properties of cement mixture was studied. In the next step, diatomaceous earth was calcinated and, lastly, the influence of replacing FGD-gypsum with anhydrite II as a setting controller in the mixture containing calcined diatomaceous earth was monitored. Technological properties of the prepared mixtures were measured and compared with cement standard. For studying the influence of phase composition and microstructure of cements hardened by both untreated and calcinated diatomaceous earth, hardened cements were tested by DTA and their porosities were measured. The results show that it is possible to prepare binder containing calcinated diatomaceous earth which has slightly lower early strengths but higher long-term strengths and lower hydration heat development.
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Rosales, Julia, Francisco Agrela, José Luis Díaz-López, and Manuel Cabrera. "Alkali-Activated Stainless Steel Slag as a Cementitious Material in the Manufacture of Self-Compacting Concrete." Materials 14, no. 14 (July 14, 2021): 3945. http://dx.doi.org/10.3390/ma14143945.
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This work develops the manufacture of self-compacting concrete (SCC) with 50% cement reduction. As an alternative binder to cement, the viability of using an alkali-activated combination of stainless steel slag (SSS) and fly ash (FA) has been demonstrated. SSS was processed applying three different treatments. Binders were manufactured mixing 35% SSS with 65% FA, as precursors, and a hydroxide activating solution. This binder was replaced by the 50% cement for the manufacture of SCC. The results obtained show good mechanical properties and durability. The study shows a reduction in the use of cement in the manufacture of SCC reusing two wastes.
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Abdykalykov, A., M. Dzhusupova, Nadia Antoniuk, and Aidai Talantbek Kyzy. "Ensuring Strength of Fine Grained Concrete with Mixed Cement Binders." Key Engineering Materials 864 (September 2020): 134–40. http://dx.doi.org/10.4028/www.scientific.net/kem.864.134.
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The article presents the results of the evaluation of the strength of fine-grained concrete of ordinary grades on mixed cement binders with ash and slag waste of thermal power plants. To ensure the required strength, the preliminary activation of the mixed binder was envisaged, which is one of the main techniques for reducing cement consumption. Experimental-statistical models of the strength properties of fine-grained concrete was obtained, which make it possible to predict the required strength with a minimum consumption of cement and the optimal concentration of ash in the binder.
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Zawal, Daniel, Krzysztof Górski, and Paweł Dłużewski. "BINDER INTENSITY AND CO2 EMISSION INDEXES FOR MORTARS CONTAINING RECYCLED AGGREGATE." Zeszyty Naukowe Uniwersytetu Zielonogórskiego / Inżynieria Środowiska 172, no. 52 (December 31, 2018): 30–39. http://dx.doi.org/10.5604/01.3001.0013.0263.
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The paper presents the use of the concept of bi (binder intensity) and ci (carbon indexes as indicators defining the effectiveness of using binders in cement composites in connection with their anthropopressive impact resulting from CO2 emissions from cement production.
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Buczyński, Przemysław, Marek Iwański, and Jakub Krasowski. "Assessment of the Impact of Hydraulic Binder on the Properties of the Cold Recycled Mixture with Foamed Bitumen and Bitumen Emulsion: Field Tests." Buildings 10, no. 12 (November 30, 2020): 223. http://dx.doi.org/10.3390/buildings10120223.
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The paper presents the results of tests of the impact of hydraulic and bituminous binders on the properties of the cold-recycled mixture (CRM). The composition of the cold-recycled mixture includes two types of different binders, i.e., bituminous binder in the form of foamed bitumen and bitumen emulsion, as well as Portland cement (CEM I 32.5R) and hydraulic binder. The hydraulic binder was produced by mixing three base ingredients in the following ratio: 40% CEM I 32.5R; 20% Ca(OH)2 and 40% CBD (cement bypass dust). The cold-recycled mixtures were produced under industrial conditions on a test section. The prepared CRM with bitumen emulsion (MCE) and foamed bitumen (MCAS) was collected from the test section and compacted under laboratory conditions. The impact of the type and kind of the binder was assessed in terms of physical properties, mechanical properties and deformation modulus (bearing capacity of subbase) of the recycled base course after 1, 7 and 28 days. It was found that the use of hydraulic binder in the recycled base course, regardless of the type of bituminous binder, reduced cohesion without reducing the remaining parameters.
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Bílek, Vlastimil, Filip Khestl, and Pavel Mec. "Hybrid Cements with Non Silicate Activators." Solid State Phenomena 259 (May 2017): 30–34. http://dx.doi.org/10.4028/www.scientific.net/ssp.259.30.
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Hybrid cements represent a relatively new type of binders which combines some of the advantages of Ordinary Portland Cement and an application of mineral admixtures and alkali activation. Hybrid cements form then blends containing a low portion of OPC and a high proportion of mineral additions (such as blast furnace flag, fly ash, metakaoline, ...). This paper discusses the properties of mortars based on carbonate based activators. Mixtures composed from Ordinary Portland Cement, ground granulated blast furnace slag, fly ash and mechanically pre-activated fly ash were optimised with the target to achieve sufficient compressive strength. The influence of ratios between powder compounds, the dosage of activator and water to binder ratios are presented.
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Çolak, Adnan. "Physical, mechanical, and durability properties of gypsumPortland cementnatural pozzolan blends." Canadian Journal of Civil Engineering 28, no. 3 (June 1, 2001): 375–82. http://dx.doi.org/10.1139/l00-123.
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This paper deals with the effect of gypsumPortland cement and gypsumPortland cementnatural pozzolan ratios on the physical, mechanical, and durability properties of gypsumPortland cementnatural pozzolan blends. The results indicate that the setting time of these paste decreases with the increase of gypsum content in the mixture, ranging from 8 to 11 min. The addition of superplasticizer increases the setting time from approximately 11 to 35 min. This increase is greatly dependent on the plasticizer admixture dosage. These blends show a kinetic of capillary water absorption very similar to that of the Portland cement binder. Sorptivity is strongly influenced by the type of binder, binder composition and waterbinder ratio. Porosity of blended gypsum binders ranges from 12% to 37%. Their water absorption is high, reaching 27% in the blends with a greater proportion of gypsum. The gypsumPortland cement blends themselves possess good water resistance, which is further enhanced by the addition of natural pozzolan and superplasticizer. The water-cured blends with the composition of 41:41:18 (gypsum : Portland cement : natural pozzolan) and 41:41:18S1 (gypsum : Portland cement : natural pozzolan : 1% superplasticizer) offer a compressive strength of approximately 20 MPa at room temperature. These blends give excellent properties retention after aging in water at 20°C for 95 days. Their good resistance to water decreases as the gypsum content in the mixture is raised. However, the strength loss for the gypsumPortland cementnatural pozzolan blends is generally less than that observed for the gypsum binder.Key words: gypsum, Portland cement, natural pozzolan, physical, mechanical, durability.
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Švec, Jiří, Tomáš Opravil, and Jiří Másilko. "Preparation of Alternative Hydraulic Binder Based on Secondary Raw Materials." Advanced Materials Research 1000 (August 2014): 12–15. http://dx.doi.org/10.4028/www.scientific.net/amr.1000.12.
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Reusing and recycling of secondary raw materials from high-volume industrial productions (especially form construction materials and binders fabrications) is very important way of conserving environment and it is also interesting from the economical point of view. The production of common hydraulic binders, especially Portland cement, burdens the environment with considerable amount of combustion gases and consumes energy in massive scale. Alternative (low – energy) binder can be used as Portland cement substitution in applications with lower mechanical properties requirements. Mined limestone wash sediments contain large amount of clay components, but there is also indispensable share of fine calcite. This composition makes these sediments a promising material for the preparation of hydraulic binders as Roman cement or hydraulic lime.
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Ding, Zhu, Zhan Xi Lu, and Yuan Li. "Feasibility of Basalt Fiber Reinforced Inorganic Adhesive for Concrete Strengtening." Advanced Materials Research 287-290 (July 2011): 1197–200. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.1197.
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Phosphate based binders are high early strength materials with a short setting time. Usually, they are used as rapid repair material for concrete structures. The feasibility of a basalt fiber reinforced inorganic binder for strengthening concrete was studied. We successfully compounded suitable phosphate binder (PB) for concrete strengthening. In the current paper, phosphate binder was to adjusted to has excellent workability, suitable setting time and fluidity. Compressive strength of phosphate binder mortar, bonding strength between PB and Portland cement mortar, and strengthening effect of PB sticked basalt fiber on concrete beam were measured. Results showed that PB has excellent adhesion with Portland cement mortar. The strengthening effect of basalt fiber reinforced PB composite on concrete beam is evident. It is feasible that concrete strengthening by basalt fiber reinforced inorganic adhesive.
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Naqi, Ali, and Jeong Jang. "Recent Progress in Green Cement Technology Utilizing Low-Carbon Emission Fuels and Raw Materials: A Review." Sustainability 11, no. 2 (January 21, 2019): 537. http://dx.doi.org/10.3390/su11020537.
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The cement industry is facing numerous challenges in the 21st century due to depleting natural fuel resources, shortage of raw materials, exponentially increasing cement demand and climate linked environmental concerns. Every tonne of ordinary Portland cement (OPC) produced releases an equivalent amount of carbon dioxide to the atmosphere. In this regard, cement manufactured from locally available minerals and industrial wastes that can be blended with OPC as substitute, or full replacement with novel clinkers to reduce the energy requirements is strongly desirable. Reduction in energy consumption and carbon emissions during cement manufacturing can be achieved by introducing alternative cements. The potential of alternative cements as a replacement of conventional OPC can only be fully realized through detailed investigation of binder properties with modern technologies. Seven prominent alternative cement types are considered in this study and their current position compared to OPC has been discussed. The study provides a comprehensive analysis of options for future cements, and an up-to-date summary of the different alternative fuels and binders that can be used in cement production to mitigate carbon dioxide emissions. In addition, the practicalities and benefits of producing the low-cost materials to meet the increasing cement demand are discussed.
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Tang Van Lam, Nguyen Doan Tung Lam, and Svetlana V. Samchenko. "Effect of ash-and-slag waste on the properties of sulphoaluminate portland cement." Vestnik MGSU, no. 8 (August 2019): 991–1003. http://dx.doi.org/10.22227/1997-0935.2019.8.991-1003.
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Introduction: there is practically no information on the utilization of ash and slag waste (ASW) application in technology of special (noncontracting, expanding, self-stressing) cements, which predetermines the relevance of research in this direction. The study investigates the properties of experimental samples from cement, ash-and-slag and sand mixtures based on sulphoaluminate Portland cement (SAC) with an additive of the ASW.
Materials and methods: a fine-particle binder material consisting of the SAC produced by the Podolsk Cement factory with a fine-grained ASW additive was used to obtain a binder mixture. Silica sand functioned as fine aggregate. All the raw materials used were local to the Russian Federation. The setting time, soundness, and strength of the binder mixture were determined according to GOST 30744-2001 standard. The specific surface area of the Portland cement was established through the use of the air permeability method utilizing of PMTs-500 instrument. The microstructure of the hardened binder mixture was studied employing electron microscopic analysis and X-ray phase analysis.
Results: the work investigates the effect of 10 %, 15 %, 20 %, and 50 % ASW additive on the water demand, strength, and setting time of the SAC. The article also explores the kinetics of hardening and structure formation of samples from the binder mixture based on the SAC and ASW for hardening under normal conditions.
Conclusions: results of the investigation allow recommending the ASW characterized by high dispersion as an additive for production of special cements without significant reduction of their properties. In the presence of the ASW, setting times of the cement mixtures virtually do not change as compared with the pure SAC. With limiting the amount of the ASW in the composition of the Portland cement, the strength characteristics do not practically change through the entire period of hardening.
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Moncea, Andreea M., Ana M. Panait, György Deák, and George Poteraș. "Binder Microstructures Developed during the Hydration Process in the System Portland Cement – Calcium Aluminate Cement – Calcium Sulfate." MRS Proceedings 1812 (2016): 71–76. http://dx.doi.org/10.1557/opl.2016.20.
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ABSTRACTLately, the investigations of binders from ternary system Portland cement (PC), calcium aluminate cement (CAC) and calcium sulfate ($C\overline S$), have gone through a larger stage of development due to their special properties such as fast setting and rapid hardening, early strength, non-efflorescence, etc. These special properties are ensured by the binder’s microstructure, developed through hydration processes and reactions between hydrate components, which allows us to use them in special environments (aggressive environments with very low or very high level of pH, environments with high temperature, etc.). The binders from this system were simply named “dry mortars”, and provide the final user with an easy processing. In order to explain the mechanical behavior of the specimens exposed in normal curing conditions (T = 20 ± 2 °C and R.H. ≈ 95%), and with different percentages of calcium sulfate (added as hemihydrate or anhydrite), research on the microstructure of the hardened system was performed using SEM and XRD investigation techniques. The analyses have been performed on the binder pastes, hydrated for 1 and 28 days. The tests results showed that the specimen with anhydrous $C\overline S$ content had the best mechanical behavior.
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Giroudon, Marie, Matthieu Peyre Lavigne, Cédric Patapy, and Alexandra Bertron. "Biodeterioration mechanisms and kinetics of SCM and aluminate based cements and AAM in the liquid phase of an anaerobic digestion." MATEC Web of Conferences 199 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201819902003.
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In biogas structures, concrete faces aggressive media during anaerobic digestion. Biological activities allow the conversion of organic matter into biogas, leading to a medium characterized by a variability of composition in time and space. In order to ensure the sustainability of this expanding industry, solutions for increasing concrete durability are needed. This study aims to analyse the deterioration mechanisms of different binders focusing on the impact of the binder nature on the medium (biochemical composition) during the digestion. Binders with favourable composition to chemically aggressive media were tested: slag cement (CEM III/B), calcium aluminate cement (CAC) and metakaolin-based alkaliactivated material (MKAA), and a reference binder: OPC (CEM I). They were exposed to three anaerobic digestion cycles in liquid phase in laboratory bioreactors. The organic acids and ammonium concentrations of the liquid phase were monitored by GC and HPIC. For OPC and slag cement pastes, the chemical and mineralogical changes were characterized by SEM/EDS and XRD. Locally, the presence of binder materials has an impact on the kinetics of the digestion reaction, and therefore on the quantities of gas produced. Ammonium concentrations were above the XA3 class range. Under the conditions explored, biodeterioration mainly led to the carbonation of cement pastes.
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Skotnicki, Łukasz, Jarosław Kuźniewski, and Antoni Szydło. "Research on the Properties of Mineral–Cement Emulsion Mixtures Using Recycled Road Pavement Materials." Materials 14, no. 3 (January 25, 2021): 563. http://dx.doi.org/10.3390/ma14030563.
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The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.
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Banevičienė, Vilma, Jurgita Malaiškienė, Jiri Zach, and Karel Dvorak. "Composite Binder Containing Industrial By-Products (FCCCw and PSw) and Nano SiO2." Materials 14, no. 7 (March 25, 2021): 1604. http://dx.doi.org/10.3390/ma14071604.
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This article analyzes the integrated effect of industrial by-products (spent fluidized bed catalytic cracking catalyst waste (FCCCw) and paper sludge waste (PSw) generated in paper manufacturing) combined with nano-SiO2 (NS) on the properties of cement binder, when a certain part of the binder is replaced with the said by-products in the cement mix. Standard testing methods were used to analyze the physical and mechanical properties of cement-based materials. For structure analysis, we used X-ray diffraction (XRD), derivative thermogravimetry (DTG), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). It was found that the replacement of cement by a combined additive of FCCCw, PSw and NS is important not only for ecological reasons (abatement of CO2 emissions and recovery of waste through secondary raw materials), but also in order to enhance the properties of cement-based binders. Presumably, higher amounts of calcium silicate hydrate (CSH) and calcium alumina silicate hydrate (CASH) in the compound binder are the result of the low content of portlandite and alite in the test specimens. The specimens modified with all three additives had the highest density (~2100 kg/m3), ultrasonic pulse velocity (UPV) (~4160 m/s) and compressive strength (~105 MPa), which was ~40% higher than in the control specimens. The average pore diameter of the complex binder decreased by 21%, whereas the median pore diameter decreased by 47%.
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Daňková, Jana, Tereza Majstríková, David Bujdoš, and Pavel Mec. "Mechanical Properties of Mortars Based on Roman Cement with the Addition of Power Plant Fly Ash." Key Engineering Materials 868 (October 2020): 39–44. http://dx.doi.org/10.4028/www.scientific.net/kem.868.39.
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Roman cement is a historic hydraulic binder, prepared by firing of limestone with high proportion of clay minerals, usually at temperatures below the sintering point. The firing temperatures of Roman cements range from 800 to 1200°C. At present, this binder is considered to be a promising material with a low carbon footprint and a long lifetime. The properties of Roman cement are influenced by many factors, especially raw materials composition and firing conditions. On the other hand, a disadvantage of mortars based on Roman cement is a slow increase of initial strength. In this paper, the influence of power fly ash admixture on the dynamics of initial strength increase was experimentally investigated. The characteristics of mortars with admixtures were compared with the properties of reference mortar without admixtures. The Roman cement Vicat Prompt TM Natural Cement (manufactured by Vicat SA, French company) was used as a binder. Based on the results of the experiment it can be stated that mortars with the admixture of power plant fly ash show higher dynamics of the increase of initial strengths than the reference mixture.
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Boutouba, Kheira, Ismail Benessalah, Ahmed Arab, and Ahmed Djafar Henni. "Shear Strength Enhancement of Cemented Reinforced Sand: Role of Cement Content on the Macro-Mechanical Behavior." Studia Geotechnica et Mechanica 41, no. 4 (December 30, 2019): 200–211. http://dx.doi.org/10.2478/sgem-2019-0020.
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Abstract Sands reinforced by hydraulic binders (cement) have constituted in recent decades a major asset for the expansion of several areas of engineering. The mechanical behavior of sand-cement mixtures has undergone some controversies studied on the Chlef sand. In this paper, we present an experimental study to investigate the mechanical behavior of a sandy soil reinforced by a hydraulic binder (cement), using the direct shear apparatus emphasizing on the shear strength characteristics and the vertical deformation variation of cemented reinforced sand. The parameters used in this study are mainly: relative density (Dr = 80%), normal stress (σn = 100, 200, 400 kPa), water content (3, 7 and 10%), cement content (2.5, 5, 7.5 and 10 %) and cure time (7, 14 and 28 days). The experimental results show that the mechanical characteristics in terms of internal cohesion (C) and internal frication angle (φ) give a better mechanical performance with the binder inclusion, and the cure conditions play an effective role on the improvement of the shear strength. This result also showed that 10% of the cement content gave us a maximum value of shear strength and an optimal influence on the mechanical characteristics. The addition of cement not only improves the shear strength of soil, but also provides diversity in the resistance against the deformations imposed load, which can be established by a dilatant character.
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Nahaev, M., M. Salamanova, and Z. Ismailova. "REGULARITIES OF THE PROCESSES OF FORMATION OF THE STRUCTURE AND STRENGTH OF A CLINKER-FREE BINDER OF ALKALINE ACTIVATION." Construction Materials and Products 3, no. 1 (July 8, 2020): 21–29. http://dx.doi.org/10.34031/2618-7183-2020-3-1-21-29.
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resource- and energy-consuming Portland cement is currently considered the most popular material in the construction industry, but its production can be attributed to the category of harmful industries in terms of the amount of emissions into the environment. Therefore, the development of a clinker-free technology for the production of binders based on mineral fine powders of aluminosilicate nature activated by an alkaline coater is a relevant and promising direction.
In the work, the laws of the processes occurring during the structure formation of clinker-free binder systems of alkaline activation on alkaline cements using blast furnace granulated slags in a finely dispersed state are studied. Formulations are given and the properties of clinker-free binders of alkaline activation on mineral fine powders from rocks of sedimentary and magmatic origin are investigated. Electron probe studies and X-ray phase analysis revealed the presence of hydrated amorphous compounds close in composition to zeolites in cement stone. An analysis of the results allowed us to determine the optimal composition of clinker-free binder alkaline activation “silicified marl + volcanic tuff (70: 30%) + Na2Si03 + Na0H” with activity ranging from 42.0 - 54.5 MPa, depending on the conditions of hardening of the samples.
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Deng, Daiqiang, Guodong Cao, and Youxuan Zhang. "Experimental Study on the Fine Iron Ore Tailing Containing Gypsum as Backfill Material." Advances in Materials Science and Engineering 2021 (April 8, 2021): 1–9. http://dx.doi.org/10.1155/2021/5576768.
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The strength of the filling body is largely affected by the properties of the binder, mineral composition, fineness, and slurry concentration of tailing. In this paper, the rheological test was conducted to determine the slurry concentration of iron ore tailing containing gypsum. Then, the samples made from slurry and three binders, Portland cement, filling plant binder, and Huazhong binder, were tested, respectively. The effects of curing time, binder-tailing ratio by mass (b/t), and slurry concentration on compression strength were investigated. The sample made from Huazhong binder and iron ore tailing presented the largest compression strength.
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Wang, Chen, and Wentao Li. "Factors Affecting the Mechanical Properties of Cement-Mixed Gravel." Advances in Materials Science and Engineering 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/8760325.
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A study has been conducted to investigate the mechanical properties of cement-mixed gravel using the unconfined compression test and the tensile test. Basic factors including the curing period, the water-binder ratio, the cement content, and the strain rate were evaluated. Ordinary Portland cement with fly ash was employed as the cementation agent for preparing cemented samples. The results indicate that the unconfined compressive strength, the deformation modulus, and the tensile strength increase with the increase in the curing period. The ratio of tensile strength to unconfined compressive strength has no distinct change after 7 days. An optimum water-binder ratio can be obtained. The unconfined compressive strength and deformation modulus decrease as the water-binder ratio decreases and increase from the optimum water-binder ratio. With the increasing of the cement content, the unconfined compressive strength increases distinctly, the deformation modulus increases significantly when the cement content is less than 4% and then increased slowly, and the failure strain increases to a peak value and then decreases. With the increasing of the strain rate, the unconfined compressive strength increases slightly and the deformation modulus increases slowly. The failure strain decreases with an increase in the strain rate.
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Belov, V. V. "SAWBOBETONE ON MODIFIED CEMENT BINDER." Bulletin of the Tver State Technical University. Series «Building. Electrical engineering and chemical technology», no. 4 (2020): 14–25. http://dx.doi.org/10.46573/2658-7459-2020-4-14-25.
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The article considers the principles of production of sawbobetone on cement binder modified with additives of soluble glass and ash of hydraulic removal of local CHP. The material based on the modified cement binder using local secondary raw materials: sawdust as a filler of sawdust and waste ash as a fine filler is effective in low-rise construction conditions.
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Zagorodnjuk, L. K., and D. A. Sumskoy. "Study of the Hydration Processes of Modified Binders by Infrared Spectroscopy." Materials Science Forum 974 (December 2019): 49–54. http://dx.doi.org/10.4028/www.scientific.net/msf.974.49.
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Many Russian and foreign scientists have been studying the processes of hydration of cement binders, but the processes of binders hydration with the use of mineral and organic additives have not been studied enough. The question of the superplasticizers influence on binder compositions consisting of cement and various mineral fillers requires a deep and detailed study in each case. In this regard, the aim of this work is to study the processes of portland cement hydration, modified by organomineral additive. Research was carried out on the study of changes occurring during the structure formation of modified binders by infrared spectroscopy (IR).
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Hernandez-Martinez, Francisco G., Abir Al-Tabbaa, Zenon Medina-Cetina, and Negin Yousefpour. "Stiffness and Strength of Stabilized Organic Soils—Part I/II: Experimental Database and Statistical Description for Machine Learning Modelling." Geosciences 11, no. 6 (June 4, 2021): 243. http://dx.doi.org/10.3390/geosciences11060243.
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This paper presents the experimental database and corresponding statistical analysis (Part I), which serves as a basis to perform the corresponding parametric analysis and machine learning modelling (Part II) of a comprehensive study on organic soil strength and stiffness, stabilized via the wet soil mixing method. The experimental database includes unconfined compression tests performed under laboratory-controlled conditions to investigate the impact of soil type, the soil’s organic content, the soil’s initial natural water content, binder type, binder quantity, grout to soil ratio, water to binder ratio, curing time, temperature, curing relative humidity and carbon dioxide content on the stabilized organic specimens’ stiffness and strength. A descriptive statistical analysis complements the description of the experimental database, along with a qualitative study on the stabilization hydration process via scanning electron microscopy images. Results confirmed findings on the use of Portland cement alone and a mix of Portland cement with ground granulated blast furnace slag as suitable binders for soil stabilization. Findings on mixes including lime and magnesium oxide cements demonstrated minimal stabilization. Specimen size affected stiffness, but not the strength for mixes of peat and Portland cement. The experimental database, along with all produced data analyses, are available at the Texas Data Repository as indicated in the Data Availability Statement below, to allow for data reproducibility and promote the use of artificial intelligence and machine learning competing modelling techniques as the ones presented in Part II of this paper.
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Rakić, Jelena, and Zvezdana Baščarević. "Improving properties of high volume fly ash binder by mechanical and chemical activation." Tehnika 75, no. 6 (2020): 553–59. http://dx.doi.org/10.5937/tehnika2005553r.
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High volume fly ash (FA) binders are characterized by long setting times and low early strength. By applying mechanical and/or chemical activation methods, it is possible to increase the reactivity of FA and improve the properties of the binder. In this paper, influence of mechanical activation of FA on the properties of binders prepared with 70% FA and 30% Portland cement was investigated. Additionally, effect of chemical activation of the binder by using sodium sulfate as activator was evaluated. The binder obtained by combining mechanical and chemical activation had the highest early strength (up to 7 days) and the shortest setting times. However, the highest strength of the binder after 90 days was obtained by applying only mechanical activation of FA.
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Vinnichenko, Varvara, and Alexander Ryazanov. "Energy Efficiency of Binder Application in Concrete." International Journal of Engineering & Technology 7, no. 4.3 (September 15, 2018): 335. http://dx.doi.org/10.14419/ijet.v7i4.3.19828.
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Theoretical calculation of the thermal effect of formation of minerals of binders is carried out. The dependence allowing calculating the thermal effect of formation of minerals of lime, gypsum, slag cement, portland cement, dolomite cement is presented. The formula also takes into account the effect of organic components in the mixture. A comparative analysis of the energy efficiency of different types of binder in concrete is carried out. It is shown that the use of slag cement in the production of concrete mix is twice as effective as portland cement. This is due to the presence in the slag of calcium oxide, which does not need energy to carry out the endothermic decarbonization reaction. Lime in the concrete composition has a rate of energy consumption is five times greater. This means, industrial waste which contains calcium oxide (slag, ash and others) can replace natural materials with high efficiency.
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Sakhno, Serhiy, Lyudmyla Yanova, Olena Pischikova, Yevhen Liulchenko, and Tetiana Sergiienko. "Study of the influence of magnetized ferromagnetic additives on the processes of cement hydration." E3S Web of Conferences 280 (2021): 07005. http://dx.doi.org/10.1051/e3sconf/202128007005.
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One of the essential tasks for a sustainable future is to reduce harmful emissions into the atmosphere significantly. Cement production is the world’s largest industrial carbon pollutant, accounting for 8 % of global emissions. More than 2.2 gigatons of carbon dioxide are emitted into the atmosphere every year. Therefore, reducing the energy intensity of products and reducing the number of harmful emissions in cement production is becoming critical. One strategy to reduce cement production emissions is to reduce the most energy-consuming component in cement – clinker. In this case, various activation methods are used for maintaining the same level of cement activity. One of these methods is the impact on the hardening binder with magnetic fields. The paper presented a study of hydration processes of blast-furnace cement activated by a magnetized ferromagnetic additive. The work established that the introduction of pre-magnetized ferromagnetic dust into blast-furnace cement composition has an activating effect on binder hydration. It shows that activation occurs both in the initial and long periods of hardening. The nature of the mutual influence of the components of the hydration system alite-lime-slag in a modified binder was revealed. The investigation determined that the ferromagnetic additive, intensifying the process of slag hardening, increases the proportion of hydrated slag by 1.5-2 times. It was revealed that the formation of the ettringite framework in the modified binder’s gel is completed within one day. It is shown that in the subsequent periods, hydration of aluminates occurs mainly due to the formation of tricalcium aluminate hexahydrate (C3AH6), which excludes destructive processes in the late periods of binder hardening. It has been established that under the action of a ferromagnetic additive, the degree of crystallization of hydro silicates in the modified binder increases.
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Brosnan, Denis A. "Characterization and Degradation of Masonry Mortar in Historic Brick Structures." Journal of Structures 2014 (April 27, 2014): 1–7. http://dx.doi.org/10.1155/2014/859879.
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This study characterized mortars from a masonry fortification in Charleston, South Carolina (USA), harbor where construction was during the period 1839–1860. This location for analysis was interesting because of the sea water impingement on the structure. The study was included as part of an overall structural assessment with restoration as an objective. The mortars were found to be cement, lime, and sand mixtures in proportions similar to ones expected from the historic literature, that is, one part binder to two parts of sand. The binder was found to be American natural cement, a substance analogous to the European Roman cement. The results suggest that the thermal history of the cement during manufacturing affected setting rate explaining why the cements were considered as variable during the mid-to-late 1800s. Fine pores were found in mortars exposed to sea water resulting from corrosion. Contemporary natural cement was shown to release calcium in aqueous solution. While this release of calcium is necessary for setting in natural and Portland cements, excessive calcium solution, as exacerbated by sea water contact and repointing with Portland cement mortars, was shown to result in brick scaling or decay through cryptoflorescence.
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Sopin, M., Sergey Klyuev, Marina Ageeva, R. Lesovik, and G. Bogusevich. "DEVELOPMENT OF RADIATION-PROOF CONCRETE COMPOSITIONS." Construction Materials and Products 3, no. 5 (December 24, 2020): 24–33. http://dx.doi.org/10.34031/2618-7183-2020-3-5-24-33.
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The article considers the possibility of using composite binders and magnetite as components of concrete with radiation-proof properties. The use of the developed concrete is possible not only when it is necessary to build nuclear power plants, but also to create bunkers or anti-radiation shelters. A special feature of concretes used for the protection and design of nuclear reactor cranes is their properties, which they must have. These properties include: low thermal conductivity, increased density, high temperature resistance, reduced values of the coefficient of thermal expansion, shrinkage and creep. Technogenic raw materials for the production of very heavy concrete are studied, the main physical and mechanical characteristics, the requirements that need to be considered in the selection of raw mix composition for protective concrete are analyzed. The paper presents a comparison of physical and mechanical characteristics, the advantages and disadvantages of introducing a binder of various types: cement, cement with a superlasticizer and a binder of low water consumption. It was found that the use of a low-water-consumption binder increases the physical and mechanical characteristics while reducing the consumption of cement in the raw material mix compared to traditional heavy concrete with cement.
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Pi, Yuhui, Zhe Huang, Yingxing Pi, Guangcan Li, and Yan Li. "Composition Design and Performance Evaluation of Emulsified Asphalt Cold Recycled Mixtures." Materials 12, no. 17 (August 22, 2019): 2682. http://dx.doi.org/10.3390/ma12172682.
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Based on an analysis of the cold regeneration mechanism of emulsified asphalt, the emulsified asphalt binders and cement were applied to prepare the cold recycled mixtures, and the main technical performances of the designed mixtures were evaluated, including high-temperature stability, water stability, and fatigue characteristics. A high content of 65% recycled asphalt pavement (RAP) material was used with some new aggregates and mineral powders, and the optimal emulsified asphalt binder and cement dosages were determined as 2.9% and 1.5% respectively. The technical performance test results show that: (1) The well-designed emulsified asphalt cold recycled mixtures have good high-temperature stability and water stability, and can meet the requirements of the road base layer and the lower layer. (2) When the stress level is lower, the fatigue performance of mixtures with lower emulsified asphalt binder dosage and lower cement content is better, but when the stress level is higher, the high dosage of emulsified asphalt binder is more favorable, while the cement content has little effect on the fatigue property. (3) The emulsified asphalt cold recycled mixtures have relatively poor fatigue resistance, and their fatigue life is significantly lower than that of the hot mixed asphalt mixtures.
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Belov, V. V. "SAWMILCOBETONE ON NON-CEMENT COMPOSITE BINDER." Bulletin of the Tver State Technical University. Series «Building. Electrical engineering and chemical technology», no. 3 (2020): 6–16. http://dx.doi.org/10.46573/2658-7459-2020-3-6-16.
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Abstract. The role and advantages of products based on a non-cement binder using wood waste compared to other types of materials and technologies are considered. The purpose of this work was to obtain a heat insulation material based on wood processing waste and non-cement binder. The cement-free binder material using sawdust as an aggregate is effective under real-world production conditions.
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Ibáñez-Gosálvez, Javier, Teresa Real-Herraiz, and José Marcos Ortega. "Microstructure, Durability and Mechanical Properties of Mortars Prepared Using Ternary Binders with Addition of Slag, Fly Ash and Limestone." Applied Sciences 11, no. 14 (July 10, 2021): 6388. http://dx.doi.org/10.3390/app11146388.
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In order to improve the contribution to sustainability of cement production, several strategies have been developed, such as the incorporation of additions as clinker replacement. Regarding the production of commercial cements with additions, those made with binary binders are mostly produced. However, the use of ternary binders for manufacturing commercial cements is still very low, at least in Spain, and they could also be an adequate solution for producing eco-friendly cements. The objective of this research is to study the effects in the long term produced by ternary binders which combine the additions of blast furnace slag, fly ash and limestone in the microstructure, durability and mechanical performance of mortars, compared to mortars without additions and mortars made with binary binders. The ternary and binary binders accomplished the prescriptions for a cement type CEM II/B. The microstructure was characterized using mercury intrusion porosimetry, electrical resistivity and differential thermal analysis. Absorption after immersion, diffusion coefficient, mechanical strengths and ultrasonic pulse velocity were studied. The best performance was noted for ternary binder with both slag and fly ash, probably produced by the synergetic effects of slag hydration and fly ash pozzolanic reactions. These effects were more noticeable regarding the compressive strength.
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Śliwiński, Jacek, Artur Łagosz, Tomasz Tracz, Radosław Mróz, and Jan Deja. "Predicting the Compressive Strength of Portland Cement Concretes with the Addition of Fluidized Bed Combustion Fly Ashes from Bituminous Coal and Lignite." Minerals 11, no. 7 (July 12, 2021): 753. http://dx.doi.org/10.3390/min11070753.
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This paper presents the results of an extensive experimental study on the effect of the addition of two types of fly ash produced during fluidized bed combustion of bituminous coal and lignite, which differ substantially in their chemical and mineral compositions, on the compressive strength of concrete. Concretes with water/binder ratios of 0.65, 0.55 and 0.45 made with CEM I 42.5 R Portland cement and gravel aggregate were tested. The analyzed amounts of fly ash added to the binder were 0, 15% and 30% by weight. Based on the results of compressive strength testing after 28 and 90 days of curing, the relationships with the water/binder ratio and fly ash content in the binder were determined. The fly ashes used were highly active and capable of pozzolanic reaction. The relationships established allow the compressive strength of concretes based on composite cement-fly ash binder to be predicted with sufficient accuracy. The results presented in this study are an important contribution to the knowledge of concretes with combined binders. They have the exploratory value of establishing the dependence of compressive strength at 28 and 90 days on binder composition and water-binder ratio. In addition, they could be used almost directly in practical applications.
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Hlavinková, Eva, Marcela Fridrichová, Dominik Gazdič, and Kateřina Havlíčková. "Laboratory Preparation of a Ternary Binder System." Advanced Materials Research 1000 (August 2014): 63–66. http://dx.doi.org/10.4028/www.scientific.net/amr.1000.63.
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Currently, the binders of self-levelling mixtures are most commonly implemented as one-component or two-component (binary) systems. One-component systems are usually Portland cement or alumina cement alone, both further modified especially by plasticizers and dispersive additives. In addition to their indisputable advantages, one-component as well as binary systems have some drawbacks including worse technological properties in the case of one-component systems based on Portland cement and higher financial costs in the case of binary systems which are usually mixtures of anhydrite II and α-gypsum. These deficiencies should be addressed by a ternary system which represents a compromise between the quality and affordability of existing systems. The basis of this ternary system is Portland cement to which an expansion agent composed of alumina cement and gypsum or dry hydrate is added. In this system, it is expected that the required strength and volume stability will be provided by Portland cement and the expander, respectively. The aim of this work is to study the ternary binder system based on Portland cement, alumina cement and gypsum or supplementary non-traditional connective components for use in the industrial production of self-levelling mixtures.
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Chernysheva, Natalia, Valery Lesovik, Roman Fediuk, and Nikolai Vatin. "Improvement of Performances of the Gypsum-Cement Fiber Reinforced Composite (GCFRC)." Materials 13, no. 17 (August 31, 2020): 3847. http://dx.doi.org/10.3390/ma13173847.
Full textAbstract:
The novelty of this paper lies in the identification of the scientific patterns of the influence of thermal power plant waste (TPPW) on the hydration mechanism and the structure of the gypsum-cement binder (GCB). The classification of raw materials for the production of GCB has been developed taking into account the genesis, which contributes to the prediction of the properties of composites. The features of the hydration phase formation and hardening of GCB have been studied taking into account the chemical, structural and morphological features of fly ash and slag. In addition, the microstructural, morphological, and thermal properties of the cured binders at a 28 day cure were determined. For the first time, scientific data on the properties of gypsum-cement fiber-reinforced composite using TPPW and microfiber have been obtained. The results show that the synergistic effect of gypsum-cement binder, TPPW, and polyamide or basalt microfiber improves the physicomechanical properties of a 28 day cured binder: compressive strength of 20 MPa, flexural strength of 8.9 MPa, and softening coefficient 0.87.
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Gurung, Deepa Humbahadur, and Vinay Kumar Jha. "Synthesis of Geopolymer from Coal Fly Ash and its Comparative Study with Fly Ash Based Ordinary Nepalese Cement." Scientific World 13, no. 13 (August 5, 2020): 24–28. http://dx.doi.org/10.3126/sw.v13i13.30502.
Full textAbstract:
The world cement industry is responsible for 5-8 % of the total CO2 emission. Thus, the cement industry has a crucial role in global warming. The search for an alternative green inorganic binder with improved durability led to the discovery of alkali-activated binder termed “geopolymer”. In this study, geopolymer was synthesized from coal fly ash (CFA) with the parameters such as particle size ≤ 53 μm, NaOH concentration 8 M and the mass ratio of CFA/Na2SiO3 was 0.75. For the comparative study with fly ash based cement, the cement mortars were prepared by varying the cements and mass ratio. The highest compressive strength (14.16 MPa) of the cement mortar was however obtained with 1:3 cement sand ratio after 7 days of curing, the ratio of 1:4 was considered for comparison. The cement and geopolymer mixture mortars were also prepared with varying (cement + sand) and (CFA+ NaOH+ Na2SiO3) mass ratio. The maximum compressive strength of 3.84 MPa was obtained for 1:2 mass ratio with 7 days of curing. The maximum compressive strengths of CFA based geopolymer, CFA added cement and cement and geopolymer mixture were 17.06, 21.3 and 11.42 MPa with 90 days of curing respectively.