Матеріалознавство
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Документ Alkaline aluminosilicate binder-based adhesives with increased fire resistance for structural timber elements(2019) Krivenko, P. V.; Guzii, S. G.; Bondarenko, O. P.The paper presents data on the use of the alkaline aluminosilicate binder-based adhesive of the system Na2O•Al2O3•(4-6)SiO2•(17-20)H2O for gluing and fire protection of structural timber elements. The results of the study of thermoresistant phases in the reaction products of the alkaline aluminosilicates are reported and discussed. The results allowed to show that at SiO2/Al2O3 between 5 and 6 the zeolite-like phases of heulandite types, which, under action of temperatures, are able to form a porous aluminosilicate artificial stone with low thermal conductivity (λ=0.09 Wt/m⋅К, DSTU B V.2.7-105-2000 (GOST 7076-99)) are formed in the reaction products. The use of the developed aluminosilicate adhesives allow for to classify the structural timber elements as hardly burnable and hardly flammable materials (GOST 12.1.044-1989, EN 13823 + A1: 2014-12, ASTM E119-07). They have the following characteristics: water resistance D3 (EN 204:2001), resistance in splitting up 7.8 MPa (GOST 16483.5-1973), adhesion in normal pull-off test up to 2.6 MPa (GOST 32299- 2013 (ISO 4624:2002)).Документ Efficiency of Redispersible Polymer Powders in Mortars for Anchoring Application Based on Alkali Activated Portland Cements(Trans Tech Publications, 2018) Rudenko, Igor I.; Konstantynovskyi, Oleksandr P.; Kovalchuk, Artem V.; Nikolainko, Marharyta V.; Obremsky, Dmytro V.Properties of dry mixes for anchoring application (increasing of mortars strength, adhesion, volume stability etc.) based on alkali activated Portland cement (AAPC) are influenced by different factors. One of them is application of chemical admixtures with different functionality. Adhesive properties are mainly achieved by redispersible polymer powders (RPP). The main problem in choice of RPP’s type is destruction of their molecules with ester links due to alkaline hydrolysis. The purpose of work was investigation of RPP’s molecular structure influence on properties of mortar for anchoring application based on AAPC and determination of the most effective. Efficiency of RPP based on copolymer of versatile acid ester was shown. The application of this RPP provides adhesion of 1.1 MPa and consistency of 190 mm. Positive effect of copolymer of ethylene and vinyl acetate was shown despite of partial destruction of RPP’s molecule as a result of alkaline hydrolysis of vinyl acetate at early terms of hardening. Negative effect of RPP is in decreasing of mortar strength. Thus this problem solving is decreasing of powder content to values which provide necessary physical-mechanical properties (strength, adhesion).