Vulcanization is a technological process that transforms plastic rubber into rubber. As a result of vulcanization, the shape of the product is fixed, and the material becomes more durable, hard and elastic. The purpose of the article is to determine the effect of octyl phenol-formaldehyde resin on the vulcanization parameters and to identify its optimal amount for the development of vibration-absorbing materials based on butyl rubber. The effect of a vulcanizing agent (octyl phenol formaldehyde resin) on the properties of the rubber compound during vulcanization was established. As a result of the study, the kinetics of vulcanization and the effect of various components on the properties of the rubber compound, such as elongation at break, conditional tensile strength and specific damping ability, were studied. This study is conducted in order to find the optimal rubber for placement in a seismic damper used in buildings and structures.

Keywords: vulcanizing group, vibration absorbing material, butyl rubber, rubber compound, vulcanization, octyl phenol formaldehyde resin, seismic damper

Currently, a large amount of research is devoted to the use of polymer composite materials applied for increasing the strength and durability of reinforced concrete elements. In compressed reinforced concrete columns, the bearing capacity depends on the eccentricity of the external force application and the corresponding stress-strain state, as well as on the arrangement and quantity of composite materials bonded to the surface of the structure. The choice of the arrangement scheme of composite materials depending on the stress state of the structure is of current interest for researchers. At the same time, studies conducted on centrally compressed elements often have contradictory effects. The main purpose of this study is to perform numerical experiment of a digital model for the centrally compressed concrete column reinforced with composite materials. The calculation results for 3 short columns with different reinforcement schemes are presented. It is shown that the use of composite materials to reinforce structures increases the bearing capacity up to 10%. Based on the study results, recommendations on the optimal schemes of reinforcement with composite clamps of inflexible columns reinforced in the transverse direction are proposed.

Keywords: reinforced concrete columns, normal sections, finite element modeling, reinforcement with composite materials

The question of economy of metal at production of building designs is considered. Measures for the organization of effective production in the current projects of high-rise and long-span buildings are proposed. Measures of increase of efficiency of construction are considered

Keywords: organization of construction; economy of construction, production of building materials

Have been given the substantiation of the need for preliminary testing of concrete beams on the transverse force. Their goal is to determine the effect of inclined cracks formed at the operating load levels, on the efficiency of the composite reinforcement in the near support sections.   The results of these tests, obtained with the shear span 1,5h0; 2h0 and 2,5 h0, that significantly affects the nature of inclined cracks. According to the results of an experiment formulated recommendations for the design of composite reinforcement.

Keywords: concrete, reinfrcement, reinforced concrete composite, CFRP, strengthening, crack, stress level, clamp, shear span, strength