Liliia Vladimirovna Il’ina ¹, Nikolai Olegovich Gichko ¹

Affiliations
1 Department of Building Materials and Special Technology, Faculty of Engineering and Information Technology, The Novosibirsk State University of Architecture and Civil Engineering (Sibstrin), Novosibirsk, RU

Abstract

At the initial phase of hardening, it is the limestone component that plays a major role in the hardening process, which acts as the substrate for the crystallization of hydrate tumors due to its chemical affinity with the products of Portland cement hydration. After 7 days, the diopside supplement influences the processes more significantly. Diopside has a high modulus of elasticity compared to the cement paste. As a result, stresses are redistributed within the cement paste and the whole composition is hardened. An increase in the quantity of diopside in the compound supplement to more than 66.7% does not provide a substantial increase in the strength of the cement paste. As the hardness of diopside is higher than the hardness of limestone, much more energy is required to grind it down to a usable component. Therefore, a further increase in the quantity of diopside in the compound supplement is not economically feasible. An evaluation of the optimum quantity of input compound mineral supplements can be made based on the ideas of close packing of spherical particles and the Pauling rules. The optimum content of the supplement is 8-8.5 % provided that its dispersion and density are close to the dispersion and density of the binder. An increase in the dispersion of the supplement reduces its optimal quantity. During the addition of mineral supplements, thermo grams show a displacement of the endoeffects' temperatures to the area of higher temperatures. If there are mineral supplements in the cement paste, which may be substrates for the crystallization of tumors, the cement paste’s structure is hardened, which is shown by the integrated thermal analysis.

Keywords

Cement Paste, Compound Mineral Supplement, Diopside, Dispersion, Integrated Thermal Analysis, Limestone, Mechanical Strength

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