Досліджено вплив наномодифікаторів на міц ність дрібнозернистого бетону. Встановлено вплив найбільш широко розповсюджених нанонаповнюва чів, а саме мікрокремнезему, каоліну, вапна та гіпсу на змінення міцності цементного каменю та дрібно зернистого бетону. Виконано порівняння впливу означених нанонаповнювачів на міцність дрібнозер нистого бетону. Показано, що найбільш ефективни ми нанонаповнювачами є речовини, що містять спо луки кальціюКлючові слова: дрібнозернистий бетон, міце ли, поверхневоактивні речовини, нанонаповнювач, наномодифікатор, міцність Исследовано влияние наномодификаторов на прочность мелкозернистого бетона. Установлено влия ние наиболее широко распространенных нано наполнителей, а именно микрокремнезема, каолина, извести и гипса на изменение прочности цементного камня и мелкозернистого бетона. Выполнено сравне ние влияния указанных нанонаполнителей на проч ность мелкозернистого бетона. Показано, что наи более эффективным нанонаполнителем являются вещества, содержащие соединения кальцияКлючевые слова: мелкозернистый бетон, мицел лы, поверхностноактивные вещества, нанонапол нитель, наномодификатор, прочность UDC 666.948: 666.972.112
48 concentrates, is of significant scientific and practical interest, and resolving it is a relevant task. 2. Literature review and problem statement Concrete, according to [1], represents the poly-structural system "matrix-filler-their interface", in which cement stone is the matrix. At the same time, cement stone is a hydration product of the dispersive system "dispersed phase-dispersion medium" in which the dispersed phase is the binder's particles and the dispersion medium is water or aqueous solutions of chemical substances. The structure of the cement stone, according to [2], is determined by the shape and content of hydrated compounds. As well as by those grains that did not react, by the volume and size of pores, including technological cracks [1],
The possibilities of increasing the interaction between the components of previously developed thermoplastic vulcanisates based on polypropylene and a combination of isoprene and nitrile butadiene rubbers were studied. The morphology of the composites was recorded by means of optical microscopy using an analytical complex based on a Leica DM-2500 optical microscope, a Leica DFC-420C digital high-resolution colour camera with a Peltier cooling system, and a specialised computer desk. The parameters of crystallisation of polypropylene were measured by differential scanning calorimetry using a DSC 204F1 Phoenix instrument (Netzsch). The physicomechanical properties of the vulcanisates were also determined. Maleinised polypropylene, a copolymer of ethylene with vinyl acetate, and their mixtures were used as compatibilising additives. Maleinised polypropylene was introduced together with polypropylene in a quantity of 1–10 parts; no changes in properties were observed with increase in the dosage above 4 parts, so this dosage was used. The copolymer of ethylene with vinyl acetate (1–10 parts) was introduced into the rubber phase at the stage of rubber mix preparation specially to improve the compatibility of polypropylene and nitrile butadiene rubber. The introduction of maleinised polypropylene leads to an increase in the workability and in the level of elastic strength properties, in particular the tensile elastic modulus and hardness. A considerable increase in the uniformity of distribution of components throughout the volume, a finer dispersion of the rubbers in the polypropylene matrix, and a reduction in the number of pores in the material were shown, and also an increase in the degree of polypropylene crystallinity measured under experimental conditions. The most positive effect is observed with the combined introduction of the copolymer of ethylene with vinyl acetate and the maleinised polypropylene: the nominal stress under elongation increases by 34%, and the elongation at break by 15%. The combined introduction of the compatibilising additives improves the compatibility of the components of the system, the phase boundaries become more diffuse, there is a reduction in the optical density of rubber-rich zones, and these zones are penetrated by polypropylene fibrils.
20. Кровельные материалы [Электронный ресурс] / Всеукраинский торговый центр в интернете prom.ua.-Режим доступа: prom.ua/-24.12.2017 г.-Загл. с экрана. Першина Л.А., Макаренко О.В. ПРИРОД-НЫЕ КРОВЛИ: ПРОШЛОЕ И НАСТОЯ-ЩЕЕ. В статье рассмотрена история природных кровельных покрытий. Выполнен сравнительный анализ, охарактеризованы свойства, преимущества и недостатки, стоимость и долговечность сланцевых, гонтовых, камышовых и дерновых кровельных покрытий, оценены перспективы использования природных кровельных материалов в Украине. Ключевые слова: природные кровли, сланцевые кровли, гонтовые кровли, камышовые кровли, дерновые кровли, экологичность, экономичность, долговечность. Pershinа L.A., Makarenko O.V. NATURAL ROOFS: THE PAST AND THE PRESENT. The article covers the history of natural roofing. The comparative analysis, characteristics, advantages and disadvantages, cost and durability of slate, shingle, thatch and green roofing coverings are characterized, prospects of use of natural roofing materials in Ukraine are estimated.
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