Research on Properties of Pressed Silicate Materials of Non-autoclave Hardening with the Addition of Synthetic Tobermorite-Like Calcium Hydrosilicates

Author(s):  
A. A. Volodchenko
Author(s):  
A. Volodchenko

In the construction of buildings and structures, many wall materials are used, including silicate products of various functional purposes. In traditional production technology of such materials, the hardening process occurs due to the formation of a crystal structure in the CaO-SiO2-H2O system. There are various ways to modify the crystalline growth of the cementing substance, one of which is the use of various kinds of crystal seedings, in particular the use of natural and synthetic calcium hydrosilicates. The purpose of the experiments is to study the possibility of improving the performance properties of non-autoclave silicate composites by modifying the structure formation in the "lime-non-traditional aluminosilicate raw materials" system, which consists in the crystal-chemical regulation of the structure formation processes with a synthetic crystal filler CaO-SiO2-H2O (C-S-H). The use of synthetic crystalline filler C-S-H synthesized by hydrothermal synthesis in an autoclave at a pressure of 1 MPa and a temperature of 175 °C from a mixture of Ca(OH)2 and crystalline silica in a ratio different C/S=1 in the technology of non-autoclave silicate materials on the basis of alternative aluminium raw material allows to increase the operational indicators resulting products to 18 % or more. The optimal content of CaO and crystal filler C-S-H at which the maximum strength characteristics are provided is 8 % and 2.5 %, respectively, which allows to develop optimal compositions of raw materials for the technology of producing high-density non-autoclave silicate materials based on non-traditional aluminosilicate raw materials with a compressive strength of at least 20 MPa and more, with an average product density of no more than 2000 kg /m3.


2020 ◽  
Vol 3 (2) ◽  
pp. 19-28 ◽  
Author(s):  
A. Volodchenko

one of the possible ways to improve the properties of building materials is to modify the processes of structure formation, which can be realized through the use of crystalline primers. In this regard, it is urgent to study the effect of artificial calcium hydrosilicates on hardening processes, as well as the properties of non-autoclave silicate materials based on non-traditional aluminosilicate raw materials. Studies have shown that the addition of artificial calcium hydrosilicates (CSH) in an amount of 1-1.5 wt. %, when the content in the mixture of CaO is less than 10 wt. %, effectively increases the strength parameters of products at all stages of heat and moisture treatment from 8 to 16%. The most intense increase in strength is observed during the heat-moisture treatment (TBO) from 3 to 6 hours and is at least 13%, while in samples without the addition of artificial calcium hydrosilicates, the strength increase is 6%. The addition of artificial calcium hydrosilicates intensifies the processes of structure formation, which ensures an increase in crystalline matter, and, due to the fibrous structure, acts as a fiber, which contributes to the nano-reinforcement of the cementing substance formed from neoplasms in the CaO-SiO2(Al2O3)-H2O system based on clay rocks and calcium oxide. Due to the accelerated set of strength, it is possible to reduce the duration of isothermal exposure while maintaining the necessary performance characteristics.


2000 ◽  
Vol 628 ◽  
Author(s):  
Takeo Yamada ◽  
Keisuke Asai ◽  
Kenkichi Ishigure ◽  
Akira Endo ◽  
Hao S. Zhou ◽  
...  

ABSTRACTMesoporous materials have attracted considerable interest because of applications in molecular sieve, catalyst, and adsorbent. It will be useful for new functional device if functional molecules can be incorporated into the pore of mesoporous material. However, it is necessary to synthesize new mesoporous materials with controlled large pore size. Recently, new class of mesoporous materials has been prepared using triblock copolymer as a template. In this paper, we reported that hexagonal and cubic structure silicate mesoporous materials can be synthesized through triblock copolymer templating, and their size was controlled by synthesis condition at condensation.


2011 ◽  
Vol 26 (12) ◽  
pp. 1327-1334 ◽  
Author(s):  
Lin-Yi ZHAO ◽  
Li LI ◽  
Zui-Xiong LI ◽  
Jin-Hua WANG
Keyword(s):  

1997 ◽  
Vol 51 (1) ◽  
pp. 39
Author(s):  
M.G. Galuzinskiy

2004 ◽  
Vol 846 ◽  
Author(s):  
Kyung M. Choi ◽  
John A. Rogers

A new family of organic/inorganic hybrid silicate materials, bridged polysilsesquioxanes, was designed and synthesized through a molecular-level mixing technique. Since hybrid materials in the molecular-composite level, whose domain sizes are in the nanometer-scale, and whose constituents often lose individual identities and thus create new properties, we obtained a set of improved properties from those organically modified glasses. By modifying the Si-O-Si polymeric network, in this study, we produced controllable, porous hybrid glasses for facile and uniform doping of various ions, metals or semiconductor particles. By taking advantage of void volume created in those molecularly modified silicate systems, novel optical materials with designed properties can thus be achieved. Via a chemical strategy, we designed hexylene- or fluoroalkylene-bridged hybrid glasses doped with both Er+3 ions and CdSe nano-particles for the development of new laser amplifier materials. In photoluminescence experiments, a significant enhancement in fluorescence intensity at 1540 nm has been obtained from the fluoroalkylene-bridged glass. The presence of CdSe nano-particles, by virtue of their low phonon energy, also appears to significantly influence the nature of the surrounding environment of Er+3 ions in those modified silicate systems, resulting in the increased fluorescence intensity.


2001 ◽  
Vol 206-213 ◽  
pp. 1985-1988
Author(s):  
Hao Shen Zhou ◽  
Takeo Yamada ◽  
Keisuke Asai ◽  
Itaru Honma ◽  
H. Uchida ◽  
...  

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