In this paper, joint precast piles with a cross-section of 400 × 400 mm and a pin-joined connection were considered, and their interaction with the soil of Western Kazakhstan has been analyzed. The following methods were used: assessment of the bearing capacity using the static compression load test (SCLT by ASTM) method, interpretation of the field test data, and the dynamic loading test (DLT) method for driving precast concrete joint piles, including Pile Driving Analyzer (PDA by ASTM) and Control and Provisioning of Wireless Access Points (CAPWAP) methods. According to the results, the composite piles tested by the PDA (by ASTM) method differ by 15 percent compared to the static load method, while the difference between the dynamic DLT (by ASTM) method and the static load (by ASTM) method was only 7 percent. So, according to the results, the alternative dynamic method DLT (by ASTM) is very effective and more accurate compared to other existing methods.
The creation of the slag-alkaline arbolite's structure is examined in this study, which is based on measurements of the deformation of the mortar component, contact zone, and filler. Composites made of slag and alkaline arbolite are among the lightest building materials available, with excellent sound insulation and low thermal conductivity. Standard measuring equipment and procedures for analyzing the chemical and physico-mechanical properties of slag-alkaline arbolite composites were employed during the experimental tests. All of the test samples were light concrete prisms with a cross section of 150x150 mm and a length of 600 mm. For comparison, one portion of the samples was constructed of slag-alkaline Portland cement, and the other portion was made of slag-alkaline binder with crushed cotton stem fibers as an organic component. The durability and deformability of arbolite were tested under Kazakhstan weather conditions and in standard hardening chambers. The arbolite underwent a compression stress that ranged from (0.3 to 0.75) Rbn of prismatic strength. It was discovered that the organic cellulose filler added to the slag-alkaline binder based on crushed cotton stalk fiber, which makes up to 70 % of the volume, has a major impact on the way structures are formed. The system becomes rigid, the elasticity changes, and the acoustic properties in this case will fix both physical and physico-chemical processes when a porous organic filler is added. The acquired results can be applied to the creation of efficient wall materials for civil buildings, including seismic zones
The present paper considers the study of creep and deformation properties of sulfur-containing arbolit exposed to various compression stresses. Investigating the creep of lightweight arbolit concretes greatly affecting the performance of bearing and envelope structures draws a special attention during the last years. This issue is of particular relevance in the regions with hot and sharp continental climate. Arbolit concrete is one of the lightest building materials with low thermal conductivity and good soundproof properties. The modern postulates of theory and practice of creation, development of high-strength arbolit concretes on the base of composite sulfur-containing binders have become the methodological framework of the present research. While carrying out scientific research, the following standard measuring and analysis methods of physical and mechanical properties have been used for sulfur-containing arbolit composites. Experimental tests have been implemented on the 28-days samples made of sulfur-containing arbolit, with the cotton plant footstalks as an organic component. The researched samples were vapor sealed with the purpose to eliminate overlapping the processes of contraction and creep. The experimental results have shown that the analysis of prisms deformation in time demonstrates certain derivation from the pattern. Deformation of prisms made of sulfur-containing arbolit loaded at the low stress level were growing at a slower rate that the same deformations at a higher stress level. No derivation has been observed for the prisms of sulfur-containing haydite concrete. For both types of concrete, creep deformation has reached the values exceeding completely recoverable deformation by a factor of 2 or all the samples, the rapid growth of creep deformation has been observed after loading, followed by the gradual slowdown of deformation growth. For sulfur-containing lightweight concretes, as the test shown, the rate of creep deformation growth depends on the hardening curve in time reflecting the process of concrete hardening. This, if compared with sulfur-containing lightweight concretes, creep of sulfur-containing arbolit concrete is significantly lower that eventually leads to the loss of creep deformation at the same stress level. The obtained results can be used when manufacturing an efficient wall material for residential construction, including seismic areas.
In the present paper, there were considered the issues of developing optimal compositions and the study of the impact of sulfur addition on strength properties of sulfur containing binders for building materials. The purpose of the research is the development of scientific principles of physical and chemical mechanics for detoxification of wastes produced by oil-processing and metallurgical industries while obtaining sulfur containing binders with enhanced adhesive and strength properties altered by the directed mechanochemical effects. While carrying out the scientific research, there have been used standard measurement methods and the methods of analysis of physical and mechanical properties of sulfur containing binding compositions obtained by the contemporary methods of analysis and testing equipment. As the result of the research, new binding substances with improved adhesive properties have been obtained and sulfur containing structural materials with the complex of enhanced physical and mechanical properties have been developed on their basis.
15 August 2020 in Series of Geology and Technical Sciences
In this paper, the authors considered the issues related to reducing negative impact of large-tonnage toxic industrial wastes on environment by means of their detoxication and application as effective binders for building materials. For implementation of scientific researches, the standard methods of analysis of physical and mechanical properties have been used for the stone based on iron and sulfur containing binders; the contemporary methods of differential and thermal, X-ray diffraction analysis, microscopic analysis and testing apparatuses have been used. While carrying out experimental research, the authors have realized a scientific hypothesis stating that for increasing the effect of additional activation for eact particles of iron- and sulfur containing additives, their co-milling has been applied. As the result, there took place mutual neutralization and detoxication of solid industrial by-products with opposite chemical properties. In the course of experimental work aimed at preliminary determination of composition and activation of sulfur-contating additives, wet grinding was done on the pebble mill by applying abrasive and impact forces. In the course of combined action of mechano-chemical activation of industrial by-products, in the presence of water, accompanied by sulfur-containing raw mixtures for manufacturing of building materials, there was used the method of mutual neutralizion of chemically hazardous substances forming a part of industrial wastes. These methods enable to reduce the consumption of a binder due to its partial replacement by toxic by-products of oil and gas industry and metallurgy. The characteristics and properties of the specimens of iron and sulfurcontaining binder have been studied at the age of 7, 14 and 28 days of air hardening. The specimens were exposed to thermal and steam curing. It was stated that air hardened iron and sulfur-containing binders at the age of 14 days have reached the ultimate compressive strength of 62.0 MPa, at the age of 28 days – 66.5 MPa, correspondingly. The same composition exposed to steam curing at the age of 28 days has compression strength of 74.5 MPa that attests to the fact that steam curing has a positive impact on gain in strength of iron and sulfur-containing binder. The obtained research results could be apllied as an effective substance for manufacturing mortars and concrets in construction industry.