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Документ Вплив органо-мінеральних комплексів на міцність і власні деформації шлаколужних цементів(ОДАБА, 2019) Кривенко, П. В.; Петропавловський, О. М.; Руденко, І. І.; Константиновський, О. П.Запропоновано комплексну органо-мінеральну добавку складу «портландцементний клінкер – електроліт – поверхнево-активна речовина», використання якої в шлаколужному цементі забезпечує сповільнення строків тужавлення, підвищення показників міцності і практично відсутність усадки (0,062 мм/м). Показано особливості роботи портландцементного клінкеру у лужному середовищі, вплив добавок солей різного аніонного типу та луговміщуючих аніоноактивних ПАР на водопотребу, синтез міцності та власні деформації при гідратації та формування структури штучного каменя на його основі. Відмічена перспективність запровадження таких органо-мінеральних комплексів в якості додаткових компонентів шлаколужних цементів для регулювання їх технологічними і фізико-механічними властивостями, у т.ч. для зменшення усадки цементного каменяДокумент Enhancement of alkali-activated slag cement concretes crack resistance for mitigation of steel reinforcement corrosion(EDP Sciences, 2020-04) Krivenko, Pavlo; Petropavlovskyi, Oleh; Kovalchuk, Oleksandr; Rudenko, Igor; Konstantynovskyi, OleksandrThe paper is devoted to mitigation of steel reinforcement corrosion in alkali-activated slag cement (further, AASC) concretes, based on soluble sodium silicates (further, SSS’s), obtained from high consistensy concrete mixes. Enhancement of AASC fine concretes crack resistance due to modification by complex shrinkage-reducing additives (further, SRA’s) based on surfactants and trisodium phosphate Na3PO4.12H2O (further, TSP) was proposed for mitigation of steel reinforcement corrosion. SSS’s were presented by sodium metasilicate (silica modulus 1.0, dry state) and water glass (silica modulus 2.9, density 1400 kg/m3). In case of sodium metasilicate the application of SRA composition “ordinary portland cement clinker – TSP – sodium lignosulphonate – sodium gluconate” provides enhancement of crack resistance starting from early age structure formation with restriction of drying shrinkage from 0,984 to 0,713 mm/m after 80 d. The effect is caused by reduction of water and by higher volume of crystalline hydrates. In turn, SRA presented by compositions “TSP – glycerol” and “TSP – glycerol – polyacrylamide” provide enhancement of AASC fine concretes fracture toughness during late structure formation with increasing ratio of tensile strength in bending to compressive strength up to 37 – 49 % if compare with the reference AASC when water glass is used.Документ Fillers for modification of polyester powder coating(IOP Publishing Ltd, 2020-09) Gots, V. I.; Lastivka, O. V.; Tomin, O. O.; Tymoshenko, S. A.In the article effectiveness of the use of fillers to improve the physical and mechanical properties of the coating varied depending on the average size of the filler particles and crystalline shape was studied. According to the indicators of impact strength to back impact and bending strength of the coating, the most effective is the use of microsilica with an average size of 2.9 μm. As the average filler size increases, the gloss and impact strength of the coating reduce. To increase the bending strength of the coating, it is advisable to use fillers in the form of wollastonite, which is characterized by a fibrous crystal shape, which improves the physical and mechanical properties of the coating and prevents cracking, acting as a reinforcing agent. In addition, the analysis of the obtained study results shows that the use of the studied Ukrainianmade fillers in the powder paint composition promotes obtaining a covering with adjustable physical and mechanical characteristics.Документ 35. The influence of complex additive on strength and proper deformations of alkali-activated slag cements(Trans Tech Publications Ltd, 2019) Krivenko, Pavel; Petropavlovskyi, Oleh; Rudenko, Igor; Konstantynovskyi, OleksandrThe peculiarity of alkali-activated slag cements (further, AASC’s) is increased proper deformations, which can cause increased cracking and reduced durability of structure. The paper is devoted to manage AASC’s proper deformations. The main task was to determine the composition of complex additives (further, CA’s) in system «ordinary portland cement (further, OPC) clinker -mineral compound of different anionic type - surfactant» in presence of sodium metasilicate (further, MS) to affect on hydrated AASC performance while ensuring effective structure of artificial stone by criterion of shrinkage deformations. Comparative analysis of hydrated cement systems "OPC clinker - MS", "OPC clinker - mineral compound - MS" and "OPC clinker - mineral compound - MS - surfactant" showed that the greatest effect on reduction of proper deformations occurs when the mineral compounds relate to electrolytes, i.e. Na2SO4 and NaNO3. Hydrated system is characterized by expansion (+0,062 mm/m) in presence of Na2SO4. Almost no shrinkage is supplied by application of NaNO3 (-0,062 mm/m). The obtained CA’s were tested in AASC. CA in the system “OPC clinker - NaNO3 - surfactant” provides the initial setting 43 min, the end - 65 min with accelerated strength. Investigated AASC can be classified as non-shrinking cement. This phenomena is ensured by increasing density, homogeneity and monolithicity of hydrosilicate formations, as well as due to formation of hydroaluminosilicate structures with different morphology by inclusion of nitrate anions.