Drilled piles installed using CFA (Continuous Flight Auger) and DDS (Drilled displacement system) technologies are relatively new construction products in the market of Kazakhstan for the last 15 years, but already today the technology has a significant practical value in the construction of the cities of Astana, Almaty and other regions. This article presents model tests of bored piles installed using Drilled Displacement System (DDS) and Continuous Flight Auger (CFA) technologies on a volumetric bench. For testing we used 1:20 scale, piles diameter was 20 mm, length was 300 mm. Drilling was performed using augers that were prepared in advance through a 3D printer. The load on the model piles was applied in steps of 39 N up to the ultimate load of 391 N. Based on the results of the study, the «settlement-load» plots of the DDS and CFA model piles were obtained, as well as a comparison of the bearing capacity of these piles by static test method. Based on the study, it was found that the DDS piles exhibit good bearing capacity performance compared to the CFA piles. Overall, the results of the study provide valuable information on the performance behavior of DDS and CFA piles, which can be used to optimize their design and installation in different soil types.

Drilled Displacement System (DDS) and Continuous Flight Auger (CFA) piles are two popular techniques used for building pile foundations that offer advantages over traditional pile systems, including improved load-carrying capacity, reduced installation time, and less spoil generation. This article presents laboratory-scaled model tests conducted on model piles installed using the Drilled Displacement System (DDS) and Continuous Flight Auger (CFA) technologies on a test tank setup filled with soil. Model piles considering a scaling factor of 1/20 with a diameter of 20 mm and a length of 300 mm were adopted for the study. Static loading is applied to the model piles and the corresponding displacements are measured during each loading phase. The results of the analysis were compared for load-settlement curves and ultimate bearing capacity estimates for both DDS and CFA piles. Based on the study, the DDS piles were observed to perform well in terms of load-carrying capacity compared to the CFA piles. Further, full-scale field tests under static load conditions were carried out on DDS-drilled piles of diameter 400 mm and length 6 m. The load-settlement response from the field test shows good agreement with the model tests. Overall, the results of the study provide valuable insights into the behavior and performance of DDS piles that can be used to optimize their design and installation in different soil types.

The article deals with the influence of molten liquid sulfur on the physical and mechanical properties of porous arbolite concrete composites. For the manufacture of arbolite-concrete composites we used porous waste corn cob crushed with sizes from 10 to 40 mm. To compare the results of research we also adopted more dense waste vegetation crushed walnut shells with sizes from 10 to 20mm.To conduct the study adopted the method of complete impregnation of arbolitobetonnyh samples liquid molten sulfur. As impregnation, material used sulfur - waste oil production in Kazakhstan. The results of the study found that with an increase in the composition of arbolite concrete composites content of cellulose organic aggregates, there is a significant increase in compressive strength and average density of lightweight concrete depending on the duration of impregnation. We have revealed that physical and mechanical properties and corrosion resistance of impregnated arbolite concrete samples are very high and these data prove that they can be recommended for use in underground and engineering structures.

Soil stabilization and reinforcement is achieved by introducing organic or mineral modifier additives, as well as complex mixtures, and this process may be accompanied by thermal or mechanical treatment of the soil. The use of pulverized metallurgical slag exhibiting hydraulic and pozzolanic properties is of particular interest. The purpose of the study was to investigate the properties of modified soil by introducing a composite mineral admixture based on unquenched lime and ground slag during mechanical treatment of the specimens under investigation. The experiment was based on mathematical planning methods and statistical processing techniques that assess the adequacy of the models by verifying the significance of the coefficients and the significance of the results obtained. The resulting models were analyzed using mathematical analysis methods for multivariate functions. The variables considered were the consumption of unquenched lime, the consumption of ground slag, the specific surface area of the ground slag, and the compaction pressure. The response functions were the strength of the modified soil at 28 days of curing under standard conditions and its average density. The studies have shown that the introduction of unquenched lime and pulverized blast-furnace slag allows for a significant improvement in the performance characteristics of the soil, especially under mechanical loading during the early stages of curing. The optimal dosage and specific surface area of granulated blast-furnace slag were determined: 363±18 kg/m³ and 383±10 m²/kg, respectively. Optimized dependencies of the soil strength and density on the lime content and compaction pressure were obtained, their graphical interpretation was performed, and an algorithm was developed for a computer program.

This paper examines certain strength characteristics of wood–concrete composites in comparison with other lightweight concretes. To address these issues, we conducted a series of experiments to study the relationship between the prismatic strength-to-cubic strength ratio, the development of strength, and the sequence of failure stages in arbolite–concrete composites with various structural characteristics under a destructive load. Our experiments confirmed that the ratio of cubic to prismatic strength in wood–concrete specimens ranges from 0.894 to 0.965 and, in some cases, approaches unity depending on the size, fibers, and microstructure of the organic aggregate. We have also established that the failure of fibrous-structured arbolite concrete specimens occurs sequentially: first, the mortar component fails, and then the organic aggregate fibers fail. In arbolite concrete specimens with a porous and coarse-pored structure, failure occurs simultaneously, as in other types of concrete. Based on the characteristics of the hardening and failure stages of arbolite–concrete composites, they can be used as wall material for building construction in regions with high seismic activity.