The article examines the influence of various superplasticizers on the performance characteristics of concrete. A series of tests of samples-beams of fine-grained concrete modified with plasticizers of various types was carried out. The optimal amount of the introduced additive was experimentally determined to compare the plasticizing effect of the cement-sand mixture. Experimental data are given indicating the main operational characteristics of the material depending on the additive used. The most effective additive "Polyplast SP-3" has been determined.

Keywords: concrete, fine-grained concrete, mixture, lignosulfonates, polycarboxylates, naphthalene sulfonates, plasticizer, superplasticizer, water demand, plasticity

This article presents the developed compositions of dry mortar mixtures for the preparation of fine-grained concrete. For the preparation of these mixtures, the technology of electromagnetic action on the dry components of solutions was applied. As a result of the use of a magnetic field to activate and increase the reactivity of the mixture, the physical and mechanical characteristics of fine-grained concrete have significantly improved. The increase in the compressive strength of the samples reached more than 70% compared to the strength of samples prepared using conventional technology without the use of magnetic treatment of dry components of the mixture.

Keywords: dry mix, magnetic treatment, linear induction rotator, fine-grained concrete, strength

Currently, loaders for piece loads used in the technological process of loading-transporting and laying barrels of oil are widely used in industry. In particular cases, during loading and transport operations, the functionality of the loader is sufficient, but when laying cargo or obstacles occur, it is necessary to maneuver using the loader chassis, which significantly increases the execution time of the technological process. The results of the conducted studies have shown that when performing the technological operation of capturing, transporting and stacking barrels, the time to move the chassis is up to 12%, while the loader performance coefficient is 0.65. Numerical modeling of the positioning process of the load-handling body of the output link of the loading and transport unit is carried out, on this basis, a loader design based on a stacker is proposed and developed. The degree of mobility of the manipulation mechanism is calculated.

Keywords: numerical modeling, loader, manipulator, hinges, chassis, structural analysis, degree of mobility, kinematic analysis, service area, lifting body, mechanism

The article presents the results of experimental studies. The optimal time of dispersion of the mixing water together with the nano-additive has been determined. The results of experiments to determine the effect of carbon nanotubes and plasticizer on fine-grained concrete are also presented. Strength characteristics were determined for the studied compositions. Based on the data obtained, the effect of the dispersion time was determined, as well as the effect of the combined use of the SikaVC 5-500 plasticizer and carbon nanotubes "Taunit-M".

Keywords: fine-grained concrete, carbon nanotubes, ultrasonic dispersion, plasticizer

The article considers the relevance of the use of nanomodified concrete in construction. The compositions of the studied mixtures are given, as well as the methods of their preparation using ultrasonic dispersion, the results of the experiment on the destructive effect of standard samples of beams are obtained. The conclusions of the obtained experimental data are presented.

Keywords: concrete, foam concrete, carbon nanotubes, superplasticizer, dispersion

The article discusses the prospects for the development of the combined technology of expanded fiber gypsum material. Based on the literature data, the optimal boundaries of the components were determined. To obtain the optimal composition, complete two-factor experiments were performed with changes in each factor at three levels. The results of the tests were obtained, on the basis of which regression equations were constructed, allowing to predict the characteristics of the resulting material, for the selection of the optimal composition.

Keywords: expanded gypsum, fibrogyps, fiber, strength, density