Vol. 4 Issue 6

Archives Journal Construction Materials and Products 2021

STABILIZATION OF SUBSIDENCE OF BUILDINGS OF MODERN MEDICAL CENTERS

https://doi.org/10.34031/2618-7183-2021-4-6-5-25
Abstract
The group of deformed structures includes buildings that have received unacceptable subsidence and deformation during the period of their construction and especially operation, which, however, do not interfere with the performance of their main functions, but may eventually collapse. Their causes are errors in engineering and geological surveys and design; violation of the rules for performing construction work and operation of buildings and structures. Long-term geodetic observations of the precipitation of the foundations of buildings on pile foundations have shown that both absolute and relative stabilized values of subsidence in the vast majority of cases are less than them and the normative limit values are calculated. Therefore, the group of deformed buildings on pile foundations includes somewhat less often similar objects with shallow foundations. The reasons for excessive subsidence of the foundations of pile foundations of buildings (and as a result, the occurrence and development of cracks and other deformations in load – bearing structures), in addition to these, are most often: unjustified use of increasing correction coefficients for the results of compression tests of highly acidic soils; the lower ends of the piles falling into layers of weak soil; the tip of the piles sinking from the design mark; overestimation of the bearing capacity of the piles due to non-compliance with the optimal time of their "rest" after immersion or erroneous interpretation of the graphs "load-pile sediment"; excessively close placement of neighboring piles in the plan, which when they are immersed, especially in the sand, leads to "pushing" up previously submerged; uneven loading of piles as part of the grillage; deformation of existing buildings and structures when driving piles near and tongue-and-groove, the development of pits, etc.
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THE USE OF NANOTECHNOLOGY FOR THE DESIGN OF BUILDING STRUCTURES

https://doi.org/10.34031/2618-7183-2021-4-6-26-47
Abstract
Russia has a developed industry of building materials, which today implements an energy- and resource-saving model of its development. The implementation of the state policy of resource conservation is carried out in two main directions: the first direction is to save resources in the production of materials, the second is to increase the production of energy–efficient materials that allow saving energy carriers during their operation. Modern construction in Russia is guided by European construction standards, which, in turn, provides for the construction of energy-saving buildings with minimal energy consumption from external sources. This is ensured by the use of structural and thermal insulation materials in the construction of external walls. In modern structural and thermal insulation materials for energy-saving construction, high requirements are imposed on their thermal properties, mechanical strength and comfort level. From the point of view of simultaneous satisfaction of these requirements, ceramic materials have obvious advantages over other materials, in particular cellular concretes, which, with almost the same level of thermal conductivity, are characterized by the least hygroscopicity and significantly greater strength. An objective prospect for the development of structural and thermal insulation ceramics is the production of hollow ceramic stones with increased thermal efficiency for their use in economical single-layer external wall structures without additional insulation. The products of individual Ukrainian manufacturers and even imported analogues of the most famous European manufacturer (Wiernerberger Company, Austria), when used in single-layer walls, do not provide regulatory requirements for the heat transfer resistance of masonry for the first temperature zone of Russia, which occupies the majority of the territory (60%). This requires the improvement of domestic products in the direction of improving their thermal characteristics (reducing thermal conductivity and increasing thermal resistance).
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EXAMINATION OF THE QUALITY OF NANOMATERIALS IN THE DEVELOPMENT AND APPLICATION OF CIRCULATING RESOURCES IN CONSTRUCTION

https://doi.org/10.34031/2618-7183-2021-4-6-48-68
Abstract
The advantage of the equality indicator is the relative simplicity of definition and the possibility of periodic monitoring. According to the equality indicator, it is possible to assign repairs and predict the service life, assess the condition of the road surface. Experimental studies have proved that there is a connection be-tween the evenness of the coating and the strength of the pavement, which opens up the possibility of determining the structural strength of non-rigid pavement, which provides a given evenness of the coating for the last year of operation before major repairs. The question of assessing the impact of the unevenness of the road surface on the processes of development and accumulation of deformations, changes in the evenness of the coating during operation remain largely open. This is due to the multifactorial nature of the problem of predicting the equality of coverage, so it is advisable to use approaches based on direct measurement methods. Most of the existing models of interaction of a pneumatic or rigid wheel with a coating are designed for problems of pavement mechanics or car theory, therefore they cannot be unambiguously applied to determine the value of the dynamism coefficient. A significant disadvantage of these solutions is insufficient consideration of the deformative properties (modulus of elasticity) of the pavement.
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THE INFLUENCE OF FORCED CARBONIZATION ON THE PROPERTIES OF GYPSUM-LIME SYSTEMS BASED ON SECONDARY RAW MATERIALS

https://doi.org/10.34031/2618-7183-2021-4-6-69-81
Abstract
The use of secondary raw materials for the production of building materials is a modern trend in solving environmental problems. In the Republic of Crimea, dumps of secondary raw materials – phosphogypsum and lime dust – have accumulated in large quantities at various enterprises. The analysis of phosphogypsum, which has been in the dumps for more than 5 years, showed that by its quality indicators it can be attributed to the 2nd grade in accordance with GOST 4013-2019, and the specific effective activity of the material (Aeff) corresponds to the I class of materials, which makes it suitable for the production of gypsum binders. Prototypes-cylinders were made from a mixture of phosphogypsum with lime dust of 1:1 composition at a pressure of 30 MPa and then subjected to hardening according to three schemes, in order to separate the passage of various types of hardening and study each of them for the physico-mechanical properties of the resulting material. The analysis of experimental data made it possible to establish the effectiveness of simultaneous flow in the system of two types of hardening – carbonate and hydration for lime and phosphogypsum components of the raw mixture, respectively. As a result of the organization of a mixed type of hardening of gypsum-lime binder, samples with a compressive strength of 26.5 MPa and a softening coefficient of 0.63 were obtained within 90 minutes. The calcium carbonate formed in the process, which is the product of the reaction between calcium hydroxide and carbon dioxide, significantly increases the water resistance of the hydration products of gypsum binder. It is established that with an optimal combination of technological factors and hardening conditions, a significant increase in the physical and mechanical characteristics of the carbonized material is possible in a short time.
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