Drebezgova M.Yu.

Associate Professor, Belgorod State Technological University named after V.G. Shukhov, Russia

Wall materials based on low-grade loams and industrial waste

https://doi.org/10.58224/2618-7183-2025-8-5-4
Abstract
Clay raw materials used in Kyrgyzstan for the ceramic industry characterized as low-plasticity , highly sensitive and saline. In addition, the high content of carbonates in loams leads to the production of low-quality bricks. In order to obtain ceramic bricks with high-quality performance characteristics, it is necessary to use innovative approaches in the preparation of clay raw materials.
The raw used materials were local loess-like loams from the Orok deposit and ash from the Bishkek thermal power plant and a surfactant – sodium naphthenate. The loam and ash subjected to mechanochemical activation by joint grinding in activator-mixer and adding sodium naphthenate together with mixing water. The dried cylindrical samples fired in the temperature range of 900, 950 and 1000 0 C.
The results of the studies showed that mechanochemical activation of ash-clay raw materials increases the plasticity of the clay-ash mass by 140 %, while reducing the molding moisture and sensitivity coefficient.
The sintering process is intensified: at a firing temperature of 950 0C and 60 % ash, it is possible to obtain a shard with a density of 1.57 g/cm3 and water absorption of 17 %. The compressive strength is 16.3 MPa.
Amorphization and destruction of raw material particles contribute to an increase in the glass phase content. As a result, open pores are tightened, forming a strong monolithic structure.
The obtained samples based on mechanochemical activation with the addition of 60 % ash have the M150 grade and frost resistance of F 25.
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DEVELOPMENT OF A MULTICOMPONENT GYPSUM CEMENT BINDER USING THE METHOD OF MATHEMATICAL PLANNING OF THE EXPERIMENT

https://doi.org/10.58224/2618-7183-2022-5-2-5-12
Abstract
In the article, using the method of mathematical planning of the experiment, the influence of formula and technological factors on the properties of hardened multicomponent gypsum-cement binders with a mineral additive finely ground to a specific surface of 300-700 m2/kg of quartz sandstone crushing screening (QSS) JSC Lebedinsky Mining and Processing Industrial Complex, Gubkin, Belgorod region, Russia was determined.
It has been established that the use of finely ground QSS as part of a gypsum cement binder with a ce-ment/QSS– 1/2 ratio contributes to ensuring its operational characteristics and stability of properties during solidification at the required level, contributing to a decrease in the concentration of CaO in the liquid phase of the hardening system.
The optimization task was to determine the conditions for the preparation of a gypsum-cement mixture with a movement of ≤ 120 mm (according to Suttord) and the beginning of the setting time of ≥ 6 min, with the provision of the maximum compressive strength of the hardened binder. An active 3-factor experiment was planned. The following were studied: the compressive strength of hardened gypsum-cement binder samples in 2 hours of hardening – Rcomp2(Y1); at 28 days of age – Rcomp28(Y2); as well as the mobility of the gypsum–cement mixture – P (Y3) and the timing of the beginning of setting - T (Y4). With the help of mathematical processing of the results of experimental studies, regression equations were obtained and with the help of nomograms constructed on the basis of mathematical expressions, the rational compositions of gypsum cement compositions were graphically and analytically determined.
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