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Title: FEATURES OF HYDRATION OF ASH-CEMENT BINDERS
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FEATURES OF HYDRATION OF ASH-CEMENT BINDERS
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1314-2704
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English
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20
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1.1
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The effective application of the evils in the construction, including road, an important area of research is to identify the characteristics of physical and chemical processes and their hydration mechanism composed gold-cement binders. By chemical, mineralogical, derivatographic, spectroscopic and X-ray analyzes established physico-chemical properties of fly ash of thermal power hydroremoval Rudnenskiy AO SSGPO (Kazakhstan). It was determined that the hydraulic ash is acidic, with a high content of SiO2 and Al2O3 (?85.8%), has a second dispersion class, with a true and bulk density of 2.95 g / cm3 and 795 kg / m3, respectively, and is itself inactive It is represented by quartz (23%), mullite (5%), vitreous matter (66%) and coal (6%). As the second component, Portland cement of the grade ??500?0? is used, which plays a dominant role in the composition of the ash-cement stone, since it provides lime (during hydration) to activate the vitreous matter of the ash. During cement hydration mainly the following new phases arise: lime - is formed in the form of basal spherulitic plates, uniaxial, negative with light refraction indices: no = 1.577 and n? = 1.544; thin needles of ettringite with no = 1.464 and ns = 1.460; granular mass of calcium hydrosilicates; individual prismatic calcite crystals with ng = 1,684 and np = 1,531, formed as a result of lime carbonization. Moreover, ettringite crystals (1.1-1.2 ?m in size) and a gel-like mass of submicrocrystalline structure related to calcium hydrosilicates of the CSH and CSH types (I and II), as a rule, are located around the grains of the initial cement, and lime crystals (size 15 -20 microns) - apart. The mechanism of hydration of hardened ash-cement binders is shown, from which it follows, firstly, that among the sets of aluminosilicate phases arising from cement hydration, only lime activates the ash, and secondly, that from the phase composition of acidic ash consisting of quartz, mullite, vitreous matter and coal, only the vitreous substance under normal conditions interacts with lime - a product of cement hydration. The function of acid ash in hardening under normal conditions, ash-cement binders is as follows: particles of quartz (partly mullite) become the active center of crystallization of hydrated phases; the microsphere interacts with high speed with lime -the product of cement hydration, as a result of which aluminosilicate hydrate phasesform in the system; following the microsphere with lime (possibly simultaneously), thevitreous phase of the ash interacts with the formation of the same aforementionedaluminosilicate phase
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conference
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20th International Multidisciplinary Scientific GeoConference SGEM 2020
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20th International Multidisciplinary Scientific GeoConference SGEM 2020, 18 - 24 August, 2020
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Proceedings Paper
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STEF92 Technology
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International Multidisciplinary Scientific GeoConference-SGEM
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SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Russian Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; C
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499-506
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18 - 24 August, 2020
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website
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cdrom
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6779
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ash; cement; binder; hydration; mechanism
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