Technobius

Examining intermediate soil properties variability through spatial interpolation methods in GIS

Sun, 15 Sep 2024 00:00:00 +0600

This study compares Kriging and Inverse Distance Weighting (IDW) spatial interpolation methods for estimating intermediate soil properties at a construction site in Astana, Kazakhstan. Using data from eight boreholes, seven engineering geological elements (EGE) were identified and analyzed at 6.5 m and 11.5 m depths. Kriging produced deformation modulus values ranging from -0.29 to 18.99 MPa at 6.5 m and -0.51 to 23.94 MPa at 11.5 m, capturing more spatial variability compared to IDW, which provided ranges of 3.3 to 18.99 MPa and 2.6 to 23.99 MPa, respectively. Kriging’s ability to account for spatial correlations resulted in more accurate predictions, particularly in areas with complex subsurface variability. Meanwhile, IDW offered reliable localized results, effective in more uniform geological conditions. The findings demonstrate that both methods are valuable for geotechnical applications, with the choice depending on data density and site variability.

Fractal model of the strength of lightweight concrete based on volcanic tuff taking into account the scale effect

Yerlan Khamza, Vladimir Selyaev, Maratbek Zhuginissov, Zhanar Zhumadilova — Mon, 16 Sep 2024 00:00:00 +0600

The study proposes a fractal model based on B. Mandelbrot's geometry. Mandelbrot geometry to describe the scale effect in concrete. It has been experimentally established that under-loading concrete undergoes degradation of its structure, which is expressed in the sequential destruction of fractals at different scale levels. It was found that the scale reduction leads to an increase in concrete strength: 20x20x20 mm specimens showed the highest strength among all four compositions (23.3-25.3 MPa). The average density of tuff concrete was also investigated: the smallest specimens had a density of 1961.3 kg/m³, while the largest specimens had a density of 1974.2 kg/m³, which is explained by the heterogeneity of the structure and pore distribution. The water permeability of concrete, evaluated through air permeability, showed that specimens with higher air permeability (30.2-30.5 s/cm³) had better water resistance (W14). These data indicate a correlation between air permeability and water resistance, which may be due to the denser structure and improved pore distribution. The study of air permeability makes it possible to predict the durability of concrete structures when exposed to moisture, as well as to improve the quality of building materials and reduce the cost of their operation.

Concretes based on technogenic wastes formed during the mechanical processing of carbonate rocks

Fri, 13 Sep 2024 00:00:00 +0600

This article considers the possibility of using technogenic waste from the mechanical processing of Sastobe carbonate rocks as coarse and fine aggregates in the production of heavy concrete. X-ray diffractometric analysis CaCO₃ d = (3.849-3.14-2.49-2.277-2.088-1.912-1.869 A⁰) and the endothermic peak in the temperature interval of 800-850°C in the differential-thermal analysis curve technogenic residues formed during mechanical processing of Sastobe carbonate rocks showed that it mainly consists of calcium carbonate. Studies have shown that fine and coarse aggregates based on carbonate rocks have a rough surface, which increases their specific surface area and ensures a strong bond with the cement stone. At the same time, technogenic waste contains 2-3% powder fraction up to 0.16 mm, this fraction serves as an active mineral mixture. As a result of research, the use of these wastes as fillers can reduce the consumption of traditional crushed stone and sand by 50% without reducing the physical and mechanical properties of concrete, replacing 50% of traditional fillers with technogenic fillers based on carbonate rocks, increasing the density of concrete (2490kg/m³), reducing its water absorption (0.66 %), strength (49.8 MPa) and frost resistance (F400) indicators made it possible to obtain concrete that is the same as the control sample and to reduce its cost without reducing the physical and mechanical properties of concrete and to improve the environmental conditions of the region.