75504 2712-8172 7 75 2017 1-179

RAR RUS 3-14 Voronezh State Technical University Nikolenko Sergey nikolenkoppb1@yandex.ru Voronezh State Technical University Sushko Elena u00075@vgasu.vrn.ru Voronezh State Technical Universit Sazonova Svetlana Sazonovappb@vgasu.vrn.ru Voronezh State Technical University Odnolko Andrey aaodnolko@vgasu.vrn.ru Voronezh State Technical Universit Manokhin Vyacheslav manohinprof@mail.ru Behaviour of concrete with a disperse reinforcement under dynamic loads Disperse reinforcement of concrete greatly contributes to the properties of the latter. Most research has dealt with the properties of disperse reinforced concrete and influence of disperse reinforcement on structures under a static load of one sign or for a regular dynamic load that is not highly intensive. In practice there might well be alternating dynamic impacts that are highly intensive and over the calculated ones, e.g., seismic ones. The paper presents the results of an experiment study of beam structures with a disperse and combined reinforcement under an alternating highly intense dynamic impact. A method of performing an experimental study of beam elements with a disperse and combined reinforcement under an alternating dynamic highly intensive impact that is based on the use of a universal dynamic stand with extra equipment. The results of the experimental studies of cubes and prisms for static and dynamic compression are discussed. The outcomes of the study of the operation of beam elements with a disperse and combined reinforcement under an alternating dynamic highly intensive impact are presented. The operation of fiber concrete structures and ferroconcrete beam elements under similar impacts are compared. The presented results of the experimental studies allow us to conclude that a disperse reinforcement has a great influence on the operation of structures with an alternating dynamic highly intensive impact and the positive effect of a combined reinforcement of structures operating under such impacts. The use of a disperse reinforcement in structures operating under alternating dynamic highly intensive impacts would enable the resistance of structures to resist these impacts. 10.18720/MCE.75.1 disperse reinforcement; fiber concrete; combined reinforcement; experimental study; alternating dynamic highly intensive impact https://engstroy.spbstu.ru/article/2017.75.1/ 01.pdf

RAR RUS 15-22 National Research Tomsk Polytechnic University Fryanova Kristina frosia5766@mail.ru National Research Tomsk Polytechnic University Perminov Valeriy perminov@tpu.ru Impact of forest fires on buildings and structures The mathematical modeling of forest fires actions on buildings and structures has been carried out to study the effects of fire intensity and wind speed on possibility of ignition of buildings. The crown forest fire is introduced as a heat and mass source defined by the empirical values of average crown fire temperature and vertical gas velocity at the top crown surface dependent on fire intensity. The hydrodynamic and thermal interactions between plume, wind flow and building are analyzed. The modeling approach is based on the use of standard non-stationary three-dimensional conservation equations that are solved numerically under the input conditions specific for large crown forest fires. 10.18720/MCE.75.2 mathematical model; buildings; constructions; forest fire; equation; finite volume; numerical method https://engstroy.spbstu.ru/article/2017.75.2/ 02.pdf

RAR RUS 23-36 National Research Moscow State Civil Engineering University Sevryugina Nadezhda nssevr@yandex.ru National Research Moscow State Civil Engineering University Stepanov Mikhail masmias@mail.ru Vertical transport: resource by the criterion of safety The issue of engineering systems safety in particular of vertical transportation is revealed. Inconsistency in the implementation of theoretical developments in practice is defined because of the probabilistic calculation of the parameters modeled by monotone-logical functions, when real systems are non-monotone functions. The duality of the results of the processes theoretical description is revealed. A typical algorithm of safety analysis is based on the deductive abilities of a researcher when drawing up a scenario of possible hazardous situations, their development and possible consequences. Critical analysis of the regulated risk assessment procedures FMEA / FMECA was carried out when compiling the criticality level matrix of the event or process. Conceptually, the risk analysis is represented by a sequence of logical steps that provide a systematic approach to the identification of hazards associated with the operation of vertical transportation. It is suggested to supplement the methodology for data records of the loss time during the nonproduction downtime with the safety parameter assessment. The condition of the vertical transportation systems and the parameter deviation vector in the dual risksafety system are established by introducing a variable value of the parameter in the probabilistic polynomial of the simulation event model. The obtained result is universally applicable, which allows us to approach to the value of the simulated criticality of the parameter through the variability of the calculations. The developed method imposes constrains on the compilation of a logical chain of assumptions in the program of the experimental research. It also allows creating adequate conditions for the operating of the physical model of the system. The modified methodology suggests table compiling of the parameter variation limits ranging the hazard rate and calculating the corresponding values of hazard factors. It is suggested to apply the developed methodology as the supplement to the existing general methodology for risk assessment at all stages of the service time of vertical transportation. The example of the implementation of the modified procedure. The developed service life parameter adjusting method reduces operation costs, ensures safety and stability of the public mobile movement abilities when using vertical transportation. 10.18720/MCE.75.3 vertical transportation; elevators; operation; failure; risk; safety https://engstroy.spbstu.ru/article/2017.75.3/ 03.pdf

RAR RUS 37-51 Don State Technical University Dedukh Dmitriy hasturd@gmail.com Don State Technical University Schsuzkiy Viktor vikluk00@mail.ru Don State Technical University Kuzmenko Anna akuzmenk2009@yandex.ru Spun concrete properties of power transmission line supports The article presents results of investigation study of physical and mechanical properties of spun and vibrated samples. Heterogeneity of freshly placed concrete was assessed for change in water to cement proportion, residual water content, density throughout the spun sample height, as well as changes in mechanical properties of hardened concrete. Analysis of experimental data showed a significant change (up to 4%) in the average density of concrete throughout the spun sample, while the overall voids content in the sludge layer increased by almost 10%, and strength of concrete changes by 18-25% along the lift height. By using the method of least squares, a consistent change in the strength of concrete along the lift height of samples was observed. An experiment, assessing the bearing capacity of spun pylons, accounting for the resulting changes in strength of concrete along the wall height, was carried out. 10.18720/MCE.75.4 spun concrete; physical and mechanical properties of the fresh concrete mechanical properties hardened concrete power transmission tower https://engstroy.spbstu.ru/article/2017.75.4/ 04.pdf

RAR RUS 52-65 JSC “B.E. Vedeneev VNIIG” Klimovich Vitaly klimvita@yandex.ru OJSC “Gazprom neft shelf” Pariev Konstantin Parev.KV@gazprom-neft.ru Reliability of scour protection design near the platform "Prirazlomnaja" Results of experimental researches of scour protection for marine ice-resistant platform (MIRP) "Prirazlomnaja" at impact of irregular waves together with a current are presented and analyzed in the article. Experimental researches were executed taking into account maintenance of the basic similarity criterions. In particular, difference of density of sea water in natural conditions and density of fresh water in modelling conditions was taking into account at physical modelling. The various directions of irregular waves relatively MIRP and various combinations of simultaneous impact of waves and currents were considered at carrying out of experimental researches. On the basis of the natural data and the results of experimental researches safety criteria for scour protection of MIRP "Prirazlomnaja" containing 4 diagnostic parameters and their critical levels (warning and ultimate) were proposed. 10.18720/MCE.75.5 design storm; waves; wave spectrum; significant height of wave; peak period of spectrum; erosion; scour protection; rock fill grading; safety criteria https://engstroy.spbstu.ru/article/2017.75.5/ 05.pdf

RAR RUS 66-75 Belgorod State Technological University named after V.G. Shukhov Klyuev Sergey Klyuyev@yandex.ru Belgorod State Technological University named after V.G. Shukhov Klyuev Alexander Klyuyev@yandex.ru

Belgorod, Russia

Daghestan State Technical University Abakarov Abakar zhurnalnauka2015@yandex.ru Belgorod State Technological University named after V.G. Shukhov Shorstova Elena Kuzik_alena@mail.ru Belgorod State Technological University named after V.G. Shukhov Gafarova Nina gafarovanina91@gmail.com The effect of particulate reinforcement on strength and deformation characteristics of fine-grained concrete One of the options to improve the reliability and increase the service life of concrete structures can be a reinforcement of the total volume of fine-grained concrete with different fiber types. The article presents the results of complex researches on studying of influence of parameters of the dispersed reinforcement (fiber, length and type of fiber, dosage by volume) and the material of the fibers of strength of disperse-reinforced fine-grained concrete on a stretching at a bend, the estimation of efficiency and accountability in the calculation of building structures. The article considers the possibility of using industrial materials. It is proven that rougher texture leads to a larger force of adhesion between the particles of filler and the cement matrix. In addition, the large surface area of angular aggregate facilitates the development of greater traction. The article considers the issues of application of steel fibers to disperse reinforcement of fine-grained concrete. As a binder we used fine ground cement and the binder with low water demand. Their physic-mechanical characteristics of binders were studied. From the results of experiments it was found that grinding cement with plasticizing additive "Polyplast SP-1" in the amount of 0.6 % by weight of cement is more intense. This shows that in addition to the plasticizing action, it has an intensifying effect at grinding; this is due to the wedging action of most additives. It is also seen that the kinetics of grinding TMC and VNV on attrition crushing granite similar and previously studied industrial raw materials. As reinforcing material steel wave fiber were used. For increasing the strength and deformation characteristics were developed by the compositions of fine-grained fiberreinforced concrete on technogenic raw materials (screening instruments) and composite binders with the use of nanodispersed powders (NDP). The use of composite binder and high-density packing of grains of filler significantly increases the strength characteristics. Optimal selection of filler allowed to receive on technogenic Sands of Kursk magnetic anomaly of the fiber-reinforced concrete with strength limit under compression – 160.2 MPa, at a bend of 31.2 MPa. 10.18720/MCE.75.6 fiber concrete disperse reinforcement fiber strength and deformation properties of concrete disperse-reinforced fine-grained concrete density at normal humidity conditions limit of tensile strength in bending tensile strength under compress https://engstroy.spbstu.ru/article/2017.75.6/ 06.pdf

RAR RUS 76-83 6506150284 0000-0003-1139-3164 Moscow State University of Civil Engineering (National Research University) Sainov Mikhail mp_sainov@mail.ru

Moscow, Russia

National Research Moscow State Civil Engineering University Zverev Andrey zverev_0591@mail.ru Workability of high rockfill dam with a polymer face The results of numerical study of stress-strain-state (SSS) of a rockfill dam with a face whose main watertight element is a polymer geomembrane. Analyses were conducted with consideration of non-linearity of contact interaction of structure elements and non-linearity of soil behavior. Bar finite elements were used for modelling of the thin geomembrane. The study was conducted on the example of Bovilla dam structural design which was built in 1996 in Albania. Initially Bovilla dam was planned to have a reinforced-concrete face, but later there was realized the design with multy-layered face consisting of PVC geomembrane, the underlying layer of soil-cement and a protection layer of reinforced concrete slabs. The face is conjugated with the concrete structure being an integral part of the dam. The results of numerical analyses showed that the weakest part of the dam design is the place of conjugation of the face with the concrete structure. The joint between the face and the concrete structure opens and the face shifts with relative to concrete surface. The polymer geomembrane may withstand these displacements without damages because the face structural design is provided with a compensating device in the form of a geomembrane loop. However, as calculations showed, the face design provokes formation of tensile stresses in protection reinforced concrete slabs and in the soil-cement underlying layer. In case the dam face was made of reinforced concrete, cracking in the face could be less probable. In our opinion, more feasible solution of the conjugation zone could be the alternative when the polymer geomembrane is placed over the face and is covered by soil protection layer. Taking into account high strength and safety of polymer geomembranes they may be recommended to be used as a backup seepage-control element of high concrete faced rockfill dams. 10.18720/MCE.75.7 geomembrane; rockfill dam; combined dam; stress-strain-state; numerical modeling; strength; soil-cement; Bovilla dam; perimeter joint https://engstroy.spbstu.ru/article/2017.75.7/ 07.pdf

RAR RUS 84-93 Tomsk State University of Architecture and Building Gusakova Natalya gusakovanata@mail.ru Tomsk State University of Architecture and Building Filyushina Kristina kri1617@yandex.ru Tomsk State University of Architecture and Building Gusakov Alexandr gam.78@mail.ru Minaev Nikolay nickolian@mail2000.ru Selection criteria of space planning and structural solutions of low-rise buildings The present study is devoted to development of methodology used for optimal selection of space-planning and structural solutions of low-rise buildings. Objective of the study is developing the system of criteria influencing the optimal selection of space-planning and structural solutions of low-rise buildings and structures aimed at enhancing the efficiency of capital investments, energy and resource saving, creating comfortable conditions for the population considering climatic zoning of the construction site. Developments of the project can be applied while implementing investment-construction projects of low-rise housing at different kinds of territories based on the local building materials. The system of criteria influencing the optimal selection of space-planning and structural solutions of low-rise buildings has been developed. Methodological basis has been also elaborated to assess optimal selection of space-planning and structural solutions of low-rise buildings satisfying the requirements of energy-efficiency, comfort and safety, and economical efficiency. Elaborated methodology enables to intensify the processes of low-rise construction development for different types of territories taking into account climatic zoning of the construction site. Development of low-rise construction processes should be based on the system of approaches which are scientifically justified; thus it allows enhancing energy efficiency, comfort, safety and economical effectiveness of low-rise buildings. 10.18720/MCE.75.8 optimal selection; energy-efficiency; comfort; safety; effectiveness of capital investments; space-planning and structural solutions; low-rise construction https://engstroy.spbstu.ru/article/2017.75.8/ 08.pdf

RAR RUS 94-105 Siberian Transport University Kosenko Sergey kosenko.s.a@mail.ru Siberian Transport University Akimov Sergey ak_s_s@mail.ru Performance characteristics of differentially quenched rails With the development of railway transport, the train speed, the traffic intensity, and the axle load all permanently increase in magnitude. This increase adversely affects the rail operation. The quantity of rail defects and, especially, the rate of rail-head surface wear both show an increase. Such service conditions require an enhanced mechanical strength of rails, their enhanced resistance to wear, and prolonged service life. In the present study, we analyze the operation performance of modern differentially quenched rails in comparison with domestic volume-quenched rails and Nippon Steel rails (Japan). For evaluating the wear resistance of rails, in the present study we carried out measurements of their side wear at curves of small radius. As a result of the study, it was found that the resistance to wear of differentially quenched DT350 rails 1.5–1.7 times exceeded the resistance of volume-quenched T1 rails. The general-purpose DT350 rails and the advanced DT370IK rails with enhanced wear resistance and enhanced contact endurance exhibited roughly identical wear rates and therefore offered equally long service periods. The Nippon Steel rails have displayed a greater resistance to wear. The side wear of those rails was found to be 1.6 times smaller than that of DT rails, and it met the normative value for surveyed curves of small radius. 10.18720/MCE.75.9 rails; differential quenching; wear; rate of wear; curves of small radius https://engstroy.spbstu.ru/article/2017.75.9/ 09.pdf

RAR RUS 106-113 National Research Moscow State Civil Engineering University Vakulenko Denis denivakulenko@mail.ru Semenov Institute of Chemical Physics Turusov Robert rob-turusov@yandex.ru Water resistance of polymer compounds Composite materials have high physical and mechanical properties, but their widespread use is hampered by a lack of tightness (impermeability to moisture and gases). Mainly this is due to the stress-strain state of the composite structure at the micro level as a result of a comprehensive extension of the polymer owing to the adhesion of the matrix to the fiber. The development of cracks and epoxy binder swelling causes its shrinkage and thus, may change the size of distribution and the internal stress patterns in glass fiber wool and lead to a partial disruption of adhesive bonds at the interface, formation of pores, cracks and other defects in the boundary polymer layer. Finally, it can be the reason of its partial detachment from the fibers’ surface. It should be noted that such changes depend mostly on the chemical structure and composition of the polymer binder. Watertight composite material development increases the possibilities of its using in many industries, including aerospace, shipbuilding, etc. In this paper the water resistance of polymer compounds was investigated by comparing the properties of the samples with modifying compounds based on epoxy resin. As a part of the study water saturation curves were determined for various compounds and curing agents, the optimal concentration of additives were measured. The results demonstrate the possibility of using of polysulfone as an additive in epoxy resin, improving the water resistance of fiber reinforced plastic. 10.18720/MCE.75.10 polymer composites; epoxy resin; water resistance; polysulfone; polyetherimide https://engstroy.spbstu.ru/article/2017.75.10/ 10.pdf

RAR RUS 114-122 Kuban State Technological University Galkin Yuriy tcmii@mail.ru Kuban State Technological University Udodov Sergey udodov-tec@mail.ru Kuban State University Vasil'eva Lada Kavkaz98@list.ru The phase composition and properties of aluminate cements after early loading It is widely recognized that the effect of loading at the early stages of hardening enables to increase strength characteristics of cement systems and composites based on them. Of particular interest is a study on the effect of compression of aluminate cements on physicomechanical characteristics, hydration process and phase transformations. The research focuses on maximum compressive and flexural strength, the peak intensity of the main phases and hydrate products, characteristics of DTA curves after early loading, studied by means of physical and chemical methods. The authors note an increased flexural strength of specimens exposed to loading at an early age. The comparison of diffractograms showed that the peaks of the main phases were reduced during the compression stage, as well as the changes in the amorphous structure of the stone. The differential thermal analysis showed no change in bound water content. 10.18720/MCE.75.11 aluminate cement; high-alumina cement; early loading; compressive strength; flexural strength; X-ray phase analysis; differential thermal analysis https://engstroy.spbstu.ru/article/2017.75.11/ 11.pdf

RAR RUS 123-128 Vladimir State University named after Alexander and Nikolay Stoletovs Zakrevskaya Lubov Lftlhbxtcrjt@yandex.ru Vladimir State University named after Alexander and Nikolay Stoletovs Lubin Petr petr.lubin@yandex.ru Vladimir State University named after Alexander and Nikolay Stoletovs Avdeev Sergey asf_vlgu@mail.ru Vladimir State University named after Alexander and Nikolay Stoletovs Gandelsman Igor sp_vlgu@mail.ru Vladimir State University named after Alexander and Nikolay Stoletovs Filippov Sergey vlsufilippov@gmail.com Dome houses made of soil-concrete based on local raw materials The work presents the results of research on the strengthening of soil basement in the center of the urban nucleus of Vladimir, which are loam, sandy loam in soft-plastic state, and also sandy loam with silt. The technology of applying the strengthening composition in the soil has been developed. The results of the investigation of physical and mechanical properties of soils and their water resistance have been presented. The microstructure of the concrete has been studied and compositions of masonry material suitable for the construction of residential premises have been developed. The advantages and prospects of development of domed buildings have been studied. The expediency of using domed buildings in terms of energy efficiency has been substantiated. The possibility of using the developed building materials for the construction of domed buildings has been considered. 10.18720/MCE.75.12 soil-concrete; magnesia binder; dome houses; strengthening of soil foundation; water resistance https://engstroy.spbstu.ru/article/2017.75.12/ 12.pdf

RAR RUS 129-138 “B.E. Vedeneev VNIIG”, JSC Ivanova Tatyana IvanovaTV@vniig.ru

21, Gzhatskaya St., Saint Petersburg, Russia, 195220

China University of Petroleum Guan Jhy 329953890@qq.com Petersburg State Transport University Nesterova Olga neona975@yandex.ru Petersburg State Transport University Prokopovich Sergey spr94@outlook.com JSC Research Center of Construction Smirnova Lybov lyubovsmirnova80@gmail.com Petersburg State Transport University Uzdin Alexander uzdin@mail.ru 0000-0002-2468-3382 “Vedeneev VNIIG”, JSC Ivashincov Dmitry vniig@vniig.ru

St. Petersburg, Russia

Modeling the design seismic input in conditions of limiting seismological information The object of the investigations is seismic input models used in structure designing under the conditions of limited seismological information. The aim of the given investigation is to propose a new variant of a seismic input model, which should be generated for the structure under consideration, taking into account main peculiarities of actual seismic excitations. The method of design seismic input generation by means of its presentation as a sum of velocity impulse and multi frequency excitation has been developed. The duration and peak value are parameters of velocity impulse. They can be presented as function of possible earthquake magnitude and hypocentral distance. Multi frequency excitation can be presented as a product of sinusoid and some envelope function. Parameters of the impulse and multi frequency excitation are determined to provide accordance of generated input characteristics with characteristics of past earthquakes. Characteristics of past earthquakes were estimated using the joined database including more than 100 records of strong earthquakes presented by Chinese and Russian experts. 10.18720/MCE.75.13 seismic input; input characteristics; peak ground acceleration; harmonious ratio; Arias intensity; cumulative absolute velocity; seismic energy density https://engstroy.spbstu.ru/article/2017.75.13/ 13.pdf

RAR RUS 139-149 Industrial University of Tyumen Kalugina Julia zvezdaneba@yandex.ru Beuth University of Applied Sciences Keck Dietmar keck@beuth-hochschule.de Industrial University of Tyumen Pronozin Yakov geofond.tgasu@gmail.com Determination of soil deformation moduli after National Building Codes of Russia and Germany The paper analyzes the differences in carrying out compression tests in accordance with the regulatory documents of Russia and Germany and subsequent processing of the obtained data. The paper gives the reasons for significant differences in the values of compression and design deformation moduli obtained from the compression test data in accordance with Russian and German National Building Codes. Approximate differences of the above-mentioned moduli have been revealed for various types of soil. The transition coefficients have been calculated for the compression and design moduli obtained from the compression test data in accordance with Russian and German National Building Codes. The paper describes the applicability of these transition coefficients. The paper presents the research results carried out within the framework of international cooperation of two universities: Industrial University of Tyumen (Russia) and Beuth University of Applied Sciences, Berlin (Germany). The results of the research prove the correctness of the calculated transition coefficients. 10.18720/MCE.75.14 compression tests; compression modulus; oedometer deformation modulus; design deformation modulus; transition coefficients; comparison of reference standards https://engstroy.spbstu.ru/article/2017.75.14/ 14.pdf

RAR RUS 150-160 Petersburg State Transport University Indeykin Andrey andrey.indeykin@mail.ru Petersburg State Transport University Chizhov Sergei sergchizh@yandex.ru Petersburg State Transport University Shestakova Ekaterina ekaterinamost6@gmail.com Petersburg State Transport University Antonyuk Anatoly aaa.12.03.1992@mail.ru Research and Design Institute "Lenmetrogiprotrans" Kulagin Nikolay lmgt@lenmetro.ru Petersburg State Transport University Smirnov Vladimir svn193921@rambler.ru Saint-Petersburg State University of Architecture and Civil Engineering Karpov Vladimir vvkarpov@lan.spbgasu.ru Petersburg State Transport University Golitsynsky Dmitriy pgupstm@yandex.ru Approximated methods of estimation of the reliability of framed railway structures of railway bridges The development of methods for rapid assessment of the reliability of span structures of beam railroad bridges is relevant in connection with the trend towards increasing loads from the reversing freight rolling stock and the speeds of movement on the main transport with a mixed cargo-andpassenger turnover. This problem is especially urgent for the creation and implementation of special technical conditions (STC) for the design of bridges on high-speed lines (BCM), as in Europe and in America, the process of improving the regulatory framework is actively being implemented and innovative developments in this field. Normative documents of the STС take into account only two opposite tendencies. The first is the reduction of equivalent loads from specialized high-speed rolling stock, the second is the increase in dynamic coefficients with an increase in speeds of up to 350 ... 400 km/h. At the same time, the documents being developed require the provision of a relatively heavy load from a special technological rolling stock when planning work on the maintenance of the railway track, as well as during the elimination of the consequences of accidents and other emergencies. The class of this load corresponds to C11, which is 78.5 % of the load of class C14, which is calculated for bridges on public railways. The authors suggests a method for estimating the reliability of a limited pass on beam span structures of a railway transport, the load from which is 10–20 % higher than the design load. A solution describing the probability of failure-free operation in the absence of a sudden failure at the level of 0.97- 0.98 is described. Such a solution is relevant for railways with normal traffic conditions with the possibility of providing high-speed rail traffic. This technical method for rapid assessment of the reliability of span structures of beam railroad bridges be used as a basis for harmonizing National Standard and for the further evolution of the codes for HSR. Bridge authorities are therefore interested in agreed methods to assess the safety, reliability, durability of existing bridges. 10.18720/MCE.75.15 failure; reliability; load intensity; trouble-free operation; high-speed movement; technological composition https://engstroy.spbstu.ru/article/2017.75.15/ 15.pdf

RAR RUS 161-170 National Research Moscow State Civil Engineering University Kharchenko Igor HarchenkoIYA@mgsu.ru National Research Moscow State Civil Engineering University Pustovgar Andrey nsm.mgsu@mail.ru National Research Moscow State Civil Engineering University Pashkevich Stanislav PashkevichSA@mgsu.ru National Research Moscow State Civil Engineering University Eremin Aleksey EreminAV@mgsu.ru National Research Moscow State Civil Engineering University Ivanova Irina IvanovaIS@mgsu.ru National Research Moscow State Civil Engineering University Bazhenov Yuri bazhenovum@mgsu.ru National Research Moscow State Civil Engineering University Kharchenko Aleksey pto-ggs@bk.ru Expanding cements hardening within the limited deformations conditions The features of expanding cement strength and structure formation at different constrained deformation conditions were studied (without constraint of deformations, uniaxial constraint of deformations, biaxial constraint of deformations, and triaxial constraint of deformations). The study was conducted for three doses of 5 %, 15 % and 25 % of expander on the calcium sulfoaluminate basis in Portland cement of CEM 42.5 mark. For experimental data interpretation in the analysis of structure and phase composition, the combination of methods of x-ray diffraction, differential scanning calorimetry and scanning electron microscopy were used. The constraint of expansion deformations has a significant impact on the volume and nature of the expanding cement pore structure, and leads to the formation in the volume of cement stones of black agglomerates, which represent the mixture of portlandite and ettringite crystals, uniformly distributed in the amorphous CSH-phase. It has been established that by increasing the expander amount and the degree of deformation constraint increases the number of black agglomerates and an increase in compressive strength. 10.18720/MCE.75.16 hydration product; amorphous phase; calcium sulfoaluminate; x-ray diffraction; Portlandite; ettringite https://engstroy.spbstu.ru/article/2017.75.16/ 16.pdf

RAR RUS 171-179 JSC "Alekseevskdorstroy" Bulanov Pavel pavel.bulanov1991@yandex.ru Kazan State University of Architecture and Engineering Mavliev Lenar lenarmavliev@yandex.ru Kazan State University of Architecture and Engineering Vdovin Yevgeniy vdovin007@mail.ru Kazan State University of Architecture and Engineering Yagund Eduard yagund1962@mail.ru The interaction between the kaolinite or bentonite clay and plasticizing surface-active agents The influence of a number of superplasticizers of various chemical bases on the physical and technical properties of clay soils has been studied. Model soils are considered as clay soils: kaolin clay with kaolinite mineral content up to 95 %, bentonite clay with montmorillonite content up to 70%. The greatest increase in the physical and technical properties of clay soils is achieved when they are modified by a polycarboxylate superplasticizer, which is due to adsorption of polymer molecules on clay minerals even with a negative charge of chips and basal planes. This is explained by the ability of side chains of the polycarboxylate ester, which has a similar composition with polyethylene glycols, to be adsorbed on the aluminosilicate layers of clay minerals by the formation of hydrogen bonds. The interaction of kaolinite and montmorillonite included in kaolin and bentonite clay with a polycarboxylate superplasticizer was studied by infrared spectroscopy. It was found that the additive under study belongs to a type of polycarboxylate superplasticizers modified with organo-silanes. Introduction to kaolin and bentonite clays leads to chemisorption with clay minerals and the formation of organomineral bonds, which leads to an increase in the strength characteristics of clays. 10.18720/MCE.75.17 Kazan State University of Architecture and Engineering https://engstroy.spbstu.ru/article/2017.75.17/ 17.pdf