Features of the Structure Formation of Silicate Bricks Obtained with the Use of Solid Waste Produced by JSC "Berezniki Soda Plant"

2019 ◽  
Vol 23 (11) ◽  
pp. 60-65
Author(s):  
S.V. Leontev ◽  
V.A. Shamanov ◽  
A.D. Kurzanov

The results of studying the structure formation features of silicate bricks obtained with the use of solid waste produced by JSC "Berezniki soda plant" are presented in this article. Various samples, such as sludge from the "closed" sump with a moisture content of 5 %, sludge from the open sump surface with a moisture content of 35 %, moistened sludge from the open sump with a moisture content of 70 %, were taken from the sludge collectors for the research. It was established the building lime meeting the requirements of GOST 9179 can be received by means of heat treatment at 950 °C of the dehydrated slime selected from the closed settler. By results of silicate brick samples forming parameters and their structure optimization it was found that the use of lime from soda production solid waste as part of lime-silica autoclave hardening binder allows to obtain silicate bricks samples, characterized by the strength grade M200. Samples microstructure studies obtained using the methods of electron microscopic and x-ray phase analysis showed that silicate samples produced with the use of soda production waste are characterized by a cementing substance heterogeneous structure and an insufficient number of tobermorite group low-basic calcium hydrosilicates formed during autoclaving. This is due to the waste material composition, namely the presence of reactive-passive components and impurities. Increasing the structural strength of samples made with the use of soda production wastes is possible due to raising the lime-silica binder specific surface area and the binder modification with fine mineral additives.

Author(s):  
S. A. Belykh ◽  
A. A. Chikichev ◽  
L. V. Il''ina ◽  
A. I. Kudyakov

The paper presents results of research into plaster coating of brick walls in humid premises. It is found that the addition of black shale and waste from flotation gold extraction from ores in the amount of 10 % of the cement bulk, increases the structure formation and strength of mortars by 34 %. X-ray phase and differential thermal analyses show that the increase in the rate of structure formation of mortars is due to the interaction of hydraulically active ground black shale with portlandite accompanied by the formation of calcium hydrosilicates. In mortars with the black shale addition, 1–2 nm pores form, which explain the increased resistance of mortars to the effloresce formation on the surface of plaster coatings of brick walls.


2021 ◽  
Vol 2131 (4) ◽  
pp. 042091
Author(s):  
N N Shangina ◽  
T Y Safonova

Abstract The possibility of obtaining mixed air binder of high strength and water resistance by using active mineral additives has been considered. In this work, the gypsum binder has been replaced by a combination of hydrated lime with active additives - metakaolin and granulated slag. The ratio effect of the silica component to the binder on the compressive strength of the stone was studied. According to the results of X-ray phase analysis, the presence of tobermorite-like calcium hydrosilicates and the absence of hydrate lime phase were diagnosed in the stone. The influence of electrolyte additives - salts with three-charged cations - on stone hardening kinetics is shown. Increase in the compressive strength of 28-day-old stone from the modified mixed air binder by 5% with the introduction of 1% of the binder mass aluminum sulfate in the mixing water was established. The use of FeCl3 solution for mixing the modified mixed air binder leads to a decrease in the compressive strength of the 28-day-old stone. The mixing of the modified mixed air binder with Al2(SO4)3 solution reduces the time of setting.


Author(s):  
A. Ahmed ◽  
R. Lesovik ◽  
W. Al'-Bo-Ali ◽  
G. Lesovik

The object of the study is the effect of the introduction of a mineral additive (Ssp = 900 m2/kg) of the fraction (0.315–5 m) of the screening out of crushing concrete scrap into Portland cement for the production of various building products and structures. A fraction of concrete scrap of 0.315–5 mm is used in the work, since the X-ray phase analysis of various fractions of concrete scrap shows that these fractions have a rational content of non-hydrated particles of C3S and C2S. It is proved that the use of finely ground concrete scrap (Ssp = 900 m2/kg) as a mineral additive in Portland cement increaseINFLUENCE OF FINE-DISPERSED ADDITIVE FROM CONCRETE SCRAP ON STRUCTURE FORMATION OF PORTLANDCEMENT s the physical and mechanical properties of concrete. Comparative physical and mechanical indicators of the hardening of composite binders indicate that the most stable results with a uniform increase in strength is a composition with 5 % mineral additive, with an increase in strength from 2 to 7 days by 36 % and from 7 to 28 days by 46 %. It is found that the most rational are the compositions with 5 % and 10 % mineral additives providing an increase in the strength of the samples by 16% compared to the control composition. Due to the high dispersion, the mineral additive from concrete scrap acts as additional crystallization centers during the hydration of Portland cement, which leads to the creation of a skeleton coral-like structure, which additionally overgrows with submicroscopic crystals. With a specific surface area of 900 m2/kg, the best conditions are created for the formation of the primary frame and its further overgrowth with various crystalline calcium hydrates, which provide optimal density and strength.


Author(s):  
S. W. Hui ◽  
T. P. Stewart

Direct electron microscopic study of biological molecules has been hampered by such factors as radiation damage, lack of contrast and vacuum drying. In certain cases, however, the difficulties may be overcome by using redundent structural information from repeating units and by various specimen preservation methods. With bilayers of phospholipids in which both the solid and fluid phases co-exist, the ordering of the hydrocarbon chains may be utilized to form diffraction contrast images. Domains of different molecular packings may be recgnizable by placing properly chosen filters in the diffraction plane. These domains would correspond to those observed by freeze fracture, if certain distinctive undulating patterns are associated with certain molecular packing, as suggested by X-ray diffraction studies. By using an environmental stage, we were able to directly observe these domains in bilayers of mixed phospholipids at various temperatures at which their phases change from misible to inmissible states.


Author(s):  
Stuart McKernan ◽  
C. Barry Carter

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.


Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.


Author(s):  
T.W. Jeng ◽  
W. Chiu

With the advances in preparing biological materials in a thin and highly ordered form, and in maintaining them hydrated under vacuum, electron crystallography has become an important tool for biological structure investigation at high resolution (1,2). However, the electron radiation damage would limit the capability of recording reflections with low intensities in an electron diffraction pattern. It has been demonstrated that the use of a low temperature stage can reduce the radiation damage effect and that one can expose the specimen with a higher dose in order to increase the signal contrast (3). A further improvement can be made by selecting a proper photographic emulsion. The primary factors in evaluating the suitability of photographic emulsion for recording low dose diffraction patterns are speed, fog level, electron response at low electron exposure, linearity, and usable range of exposure. We have compared these factors with three photographic emulsions including Kodak electron microscopic plate (EMP), Industrex AA x-ray film (AA x-ray) and Kodak nuclear track film (NTB3).


2020 ◽  
Vol 787 (12) ◽  
pp. 34-39
Author(s):  
L.A. Abdrakhmanova ◽  
◽  
K.R. Khuziakhmetova ◽  
R.K. Nizamov ◽  
V.G. Khozin ◽  
...  

A comparison of small doses (up to 0.7 mass part) of impact strength modifiers of foreign and domestic production in polyvinylchloride-based compositions is given. Domestic acrylicnitrile- butadiene styrene modifiers (ABS) were used. The developed shock-resistant polyvinylchloride compositions in the presence of ABS elastifier have high melt fluidity, which has a beneficial effect on the recyclability. Changes in supramolecular structure were estimated from thermomechanical testing and electron microscopy data for both unfilled and filled PVC samples. Thermomechanical analysis showed that the presence of ABS modifier had a favorable effect on the technological properties of PVC-based samples. Electron-microscopic images indicate that in unfilled PVC samples, the heterogeneous PVC structure is expressed in the presence of ABS copolymer in comparison with foreign acrylic modifiers. When the compositions are filled with micro-heterogeneous structure in dispersion medium, the filler-polymer is formed by chalk particles, while ABS elasticifier is at the phase interface. Due to the peculiarities of the structure ABS has a higher degree of “fixation” on the surface of the chalk particles in comparison with the basic compositions containing acrylic modifiers, which with increasing chalk concentration leads to lower wear and tear on the top of the forming equipment.


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