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Документ Effect of technological factors on freeze-thaw resistance of alkali-activated slag cement concrete in NaCl solution(AIP Publishing, 2023) Krivenko, Pavel; Rudenko, Igor; Konstantynovskyi OleksandrThe application of alkali-activated slag cement concrete (hereinafter AASC concrete) is relevant for building constructions which are exploited in aggressive environments with exposed class XF4. It is due to increased freeze-thaw resistance of AASC concrete in water solutions of salts if compared with portland cement concrete. The aim of this work was to investigate the effects of technological factors on porous structure and freeze-thaw resistance of plasticized AASC concrete in NaCl solution. It was shown that increasing of fresh concrete consistency from class S1 up to class S4 due to plasticization by complex admixture “polyorganohydrosiloxane - sodium lignosufonate - polyethylene glycol” as well as application of alkaline component in dry form, in contrast to liquid form, ensures negative changes in porous structure of AASC concrete. These changes cause decreasing of freeze-thaw resistance from mark F500 down to F200. It was revealed that hardening of plasticized AASC concrete under normal conditions (t = 20±2 °С, RH = 95±5%), compared with hardening in water or under steam curing (t = 85±5 °С), ensures more effective porous structure which causes maintained freeze-thaw resistance of F300 in contrast to F200 and F250 agreeable. Effective technological decisions for advanced freeze-thaw resistant of AASC concrete were determined.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.