As part of the work on the PhD thesis on the creation of new systems and calculation devices for the design of reinforced concrete tanks for the storage of liquefied natural gas, work was done to determine the properties of concrete mixtures used in the construction of tanks in Vietnam, namely in the Hanoi area. A feature of the materials used for the manufacture of concrete is the use of local rocks, which have distinctive properties, which affects the strength and deformation properties of concrete. The article presents the results of experimental studies of the properties of concretes made with Vietnamese materials. A relationship was established between the modulus of elasticity of concrete and its prismatic compressive strength. As part of the study, 16 formulas of concrete mixtures on different materials from Vietnam were compiled and studied. As a result of the conducted research, the dependence of the modulus of elasticity and the intended strength of concrete was revealed, which will later be used in the creation of calculation devices for the design of reinforced concrete structures.

Keywords: concrete, reinforced concrete, materials, structures, modulus of elasticity, prismatic strength of concrete, deformations

This article is devoted to determining the main characteristics and properties of concretes made from different concrete mixtures based on Vietnamese materials. A total of 16 formulas of concrete mixtures were studied. Concrete samples were tested to determine deformations under prolonged loading. Based on the data obtained, the main creep characteristics were determined, these are the creep measure C0 and the creep coefficient ϕ, as well as additional characteristics including prismatic strength and the initial modulus of elasticity of concrete. The main purpose of this study was to determine the dependencies of the prismatic strength of concrete Rpr, as its main indicator, in relation to the creep coefficient of concrete ϕ. In conclusion, experimental data on the creep coefficients of concrete ϕ were compared with the normative values found according to SP 63.13330 and conclusions were drawn on the effect of concrete creep on its prismatic strength of concrete Rpr made from concrete.

Keywords: concrete, reinforced concrete, structures, materials, creep, deflections, deformations, prolonged loading

The article considers modern methods of seismic and seismic isolation. Traditional methods have long been used in construction practice, but special methods allow to significantly reduce costs and increase the reliability of erected structures. In modern design solutions, it is impossible to increase seismic resistance, only by increasing the cross sections, strength, and weight. New effective methods of seismic protection are required. Such solutions imply a change in mass and rigidity, damping the system depending on its movements and velocities. Thus, the use of seismic protection with proper design can significantly increase such characteristics as: building reliability, safety and reliability of equipment, economic indicators of the building.

Keywords: seismic isolation, seismic, seismic protection, damping, cost-effectiveness