33407 2304-6295 4 79 2019 1-76

RAR RUS 7-19 National Research Moscow State Civil Engineering University, Moscow, Russia Lam Tang National Research Moscow State Civil Engineering University Xuan Hung National Research Moscow State Civil Engineering University Kim Dien National Research Moscow State Civil Engineering University Bulgakov Boris Effect of complex organo-mineral additive on the deformation of hydrotechnical concrete This paper presents the experimental results of an investigation on the effect of the water-binding ratio (W/B) and the complex organo-mineral modifying additive, consisting of fly ash (FA) TPP «Vung Ang», silica fume SF-90 (SF90) and polycarboxylate superplasticizer SR 5000F (SR5000) on the deformations of concrete specimens fully immersed in 5 % sodium sulfate solution according to Russian standard GOST P 56687-2015. In addition, using the mathematical planning method for four factors and the Matlab program was obtained the first-order regression equation of the mathematical model, which was adequately described the influence of the W/B, FA, SF90 and SR5000 contents on the deformation of concrete. The experimental results of the present study monstrated that the effect of FA content is more pronounced than the water-binding ratio and content SF90. In addition, the effect of SR5000 content on the deformation of concrete is negligible, so it was discarded. The increase in the deformation of concrete samples with an increase in the fly ash content can be explained by a significant fly ash content (from 20 to 40 % by mass of cement) containing 24.17 % Al2O3 and 6.15 % Fe2O3, which are under the influence of a liquid sulphate medium and Ca(OH)2 promotes the formation of high-water of calcium hydro sulfoaluminate and calcium hydrosulfoferrites with a large-volume in capillaries of concrete. 10.18720/CUBS.79.1 69 hydrotechnical concrete; sulfate-resistant Portland cement; fly ash; microsilica; deformation; complex organo-mineral additive; experimental model; objective function; https://unistroy.spbstu.ru/article/2019.79.1/ 79_1.pdf

RAR RUS 20-36 Peter the Great St. Petersburg Polytechnic University Martynov Gleb martynovgleb@rambler.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Peter the Great St. Petersburg Polytechnic University Monastyreva Daria 12dm02@rambler.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Pereladova Ekaterina Peter the Great Saint Petersburg Polytechnic University Pertseva Olga

Polytechnicheskay, 29

0000-0001-7173-5897 Peter the Great St. Petersburg Polytechnic University Daurov Zaur Soslanovich

St. Petersburg, Russian Federation

Peter the Great Saint Petersburg Polytechnic University Tikhonov Roman

Polytechnicheskay, 29

Modeling a beam column using a micropolar model This article discusses the micropolar model, which allows to describe the nonlinear process of concrete loosening in the post-peak zone by separating the relative deformations into the plastic and linear parts, as well as from the calculation on each plane of the microplans. Such a model was used to perform various three-dimensional samples in order to demonstrate its regularization properties. Several numerical samples were investigated and compared with the results of experiments that were conducted recently. In addition, the results were compared with an extended Drucker-Prager material model. All numerical examples were modeled in the ANSYS APDL environment. After performing the calculations, results were obtained for descending and ascending loads. Variable deformations were obtained for the load down and for the load up. We also compared the load-displacement curves of the current model and previous studies (experiment and simulation with SOLID65) for the downward and upward loads, respectively. Finally, characteristic load values and maximum deflections for various modeling sources were given for the load down and for the load up. 10.18720/CUBS.79.2 69 micropolar theory; finite element method; micro-plans; the deformation of the concrete; sustainability; modeling; micro-fractures; https://unistroy.spbstu.ru/article/2019.79.2/ 79_2.pdf

RAR RUS 37-46 Svirskiy Bochkareva btm-tsp.ru@mail.ru Type of operation of the reinforced brick columns Research objective – studying of character work of a stone laying on the example of brick columns with various options of reinforcing and also definition of extent of coupling of woven composite materials with masonry solution. The relevance of use of woven composite materials as the reinforcing material is described. The main advantages of woven composite materials are specified. Pilot studies with application of samples of brick columns are conducted. The experiment by definition of coupling of the reinforcing layer with masonry solution is executed. The additional actions providing increase in coupling of fiber glass fabric and solution are described. The analysis of the results received on the basis of calculations and experiments for determination of durability on compression of brick columns is made. Conclusions about applicability of the offered system of reinforcing are formulated. 10.18720/CUBS.79.3 69 stone laying the reinforced laying combined reinforcement reinforcing by fiber glass fabric a women composite stone laying https://unistroy.spbstu.ru/article/2019.79.3/ 79_3.pdf