75504
2712-8172
Magazine of Civil Engineering
8
124
2023
1-152
RAR
RUS
12401-12401
Peter the Great Saint Petersburg Polytechnic University
Sabri
Mohanad Muaya
mohanad.m.sabri@gmail.com
Polytechnicheskay, 29
Department of Civil Engineering, COMSATS University Islamabad
Ihson
Jehangir
ihson.j@gmail.com
Abbottabad, Pakistan
Department of Civil Engineering, COMSATS University Islamabad
Fahad
Amin
fahadamin77@gmail.com
Abbottabad, Pakistan
Department of Civil Engineering, COMSATS University Islamabad
Hasib
Rehman
haseeb.rehman914@gmail.com
Abbottabad, Pakistan
Stabilization of expansive soil with lime and brick dust
Expansive soils in construction pose significant challenges due to their low strength, high compressibility, and potential for swelling. The article is dedicated to assessing the effectiveness of using lime and brick dust as additives to enhance the properties of highly plastic soils. Various tests were performed on soil samples treated with different lime and brick dust concentrations, including moisture content, maximum dry density, unconfined compressive strength, yield strength, plasticity, and swelling index. The results indicate that the addition of 5 % lime improved the soil's strength properties, resulting in a significant increase in its compressive strength. With increased lime concentration, a decrease in plasticity was observed, indicating that the soil became less plastic. Scanning electron microscopy analysis revealed changes in the surfaces and pores of the treated soil samples, suggesting structural changes induced by the lime and brick dust treatment. Furthermore, adding lime significantly reduced the plasticity index of the soil, and brick dust reduced the soil's swell index, with the lowest index of 8 % observed in the sample treated with 5 % lime and 30 % brick dust. The study's findings suggest that lime and brick dust can improve the stability of expansive soils, rendering them more suitable for construction purposes.
10.34910/MCE.124.1
624
expansive soils
lime
brick dust
stabilization
compressive strength
plasticity
swell index
SEM analysis
construction
sustainable
https://engstroy.spbstu.ru/article/2023.124.1/
RAR
RUS
12402-12402
6506150284
0000-0003-1139-3164
Moscow State University of Civil Engineering (National Research University)
Sainov
Mikhail
mp_sainov@mail.ru
Moscow, Russia
Concrete face rockfill dam located on deformed foundation: stress-strain state
Concrete face rockfill dam (CFRD) located on soil foundation has a composite structure of the seepage control facility. It includes three elements: the dam concrete face, the seepage control cuttoff wall (CW) in the foundation and the concrete apron connecting them. There is an urgent task to study workability and stress-strain state (SSS) of the seepage control facility as a whole structure as well as each element separately. Method. The SSS analysis of an abstract dam with the aid of numerical modeling was conducted to solve this task. A 100 m high CFRD located on a 100 m thick foundation layer was considered. Analyses were conducted for several alternatives of foundation soils with deformation modulus from 40 to 5000 МPа. Results. The analyses showed that the SSS of the dam on the soil foundation drastically differs from the SSS of the dam on the rock foundation. The concrete face and the cuttoff wall are subject to considerable compressive longitudinal forces. Due to bending deformations in CW and the concrete apron, considerable tensile stresses may occur. Conclusions. A number of recommendations was formulated for providing strength of the elements of the composite seepage control facility of the dam on soil foundation. To provide strength of the concrete face it is necessary that the deformability of the dam soil be close to the foundation soil. To provide CW with strength, it is recommended use the material with rigidity of no more than by 2–3 times greater than the foundation soil rigidity. The most vulnerable element of the structure of the composite seepage control facility is the concrete apron. To avoid cracking in it, it should be cut by transversal joints to form separate slabs.
10.34910/MCE.124.2
69.01
dams
concrete face rockfill dam (CFRD)
cutoff wall
stress-strain state
finite element method
soil foundation; numerical modelling
https://engstroy.spbstu.ru/article/2023.124.2/
RAR
RUS
12403-12403
57196066346
0000-0002-8051-5914
National Research Moscow State Civil Engineering University
Denisov
Aleksandr
den-al-v@inbox.ru
Moscow, Russia
Radiation changes in hardened Portland cement paste under the influence of gamma radiation
The possibility of using materials in radiation protection shields when designing new and extending the service life of existing nuclear energy facilities requires knowledge or the ability to predict their radiation changes. The studies were carried out due to the lack of data sufficient to predict radiation changes in hardened Portland cement paste (HPCP) and concrete under the influence of gamma radiation when used as radiation shield materials for nuclear energy facilities. The research is based on published data on the effect of gamma radiation on concrete at irradiation temperatures of 20–30 °C and on HPCP at 70–375 °C. The author carried out computational and analytical studies to assess and establish the possibility of predicting radiation changes in HPCP under the influence of gamma radiation. The studies were conducted using the previously developed and tested method of analytical determination of radiation changes in concretes according to data on changes in their components. The formulas used in this method made it possible to determine (restore) the radiation changes of the HPCP from experimental data on radiation changes in concretes and aggregates. According to the available results of concrete irradiation, changes in linear dimensions and strength during compression of HPCP under the action of only gamma radiation were calculated (restored). The dependences of radiation changes in HPCP on the magnitude of the absorbed dose in the range from 3.8×104 to 4.7×108 Gy after irradiation at 20–30 °C were established. According to the available data on the irradiation of HPCP with gamma radiation at temperatures from 70 °C to 375 °C, the effect of the irradiation temperature on radiation changes in the HPCP was revealed. Mathematical expressions that approximate the established dependencies are selected. On the basis of the obtained mathematical expressions, radiation changes in the linear dimensions and strength of HPCP for compression, caused only by the action of gamma radiation, after irradiation to the values of absorbed doses from 3×104 Gy to 1×1010 Gy were calculated. The calculations of radiation-thermal changes in the linear dimensions and strength of HPCP under the action of gamma radiation and heating after irradiation to the values of absorbed doses from 3×104 Gy to 1×1010 Gy and the accompanying heating at temperatures from 20 °C to 500 °C were estimated.
10.34910/MCE.124.3
691.3:691.542:621.039.538:620.1
Portland cement
hardened cement paste
gamma radiation
influence of heating
radiation changes
radiation damage
thermal changes
linear dimensions
strength
forecasting
https://engstroy.spbstu.ru/article/2023.124.3/
RAR
RUS
12404-12404
57219197083
0000-0001-5922-5122
University of Baghdad
Kharnoob
Majid
dr.majidkharnoob@coeng.uobaghdad.edu.iq
Baghdad, Iraq
Planting steel reinforcement for concrete columns
This study presents a scenario where the embedding of dowel reinforcement for new columns was inadvertently omitted during the casting of concrete columns. This oversight necessitated the implantation of steel reinforcement into pre-existing cast areas. Owing to the high density of the primary slab reinforcement, implantation was feasible only up to half the slab's thickness. By modifying the superplasticizer (SP) dosage during mixing, we achieved a consistent slump of approximately 150 mm across various concrete mixes, ensuring that both slump and slump flow remained within expected limits. The properties of these mixes, both in their fresh and hardened states, are detailed in Table 2. The sieve segregation index consistently remained below 1.3 %, indicating exceptional cohesion in all concrete mixes. In fact, no segregation was observed, with all measured segregation widths being zero. In terms of strength, the cylinder strength increased significantly with the increase in fiber volume from 0 % to 2 %. This study also examines the impact of steel reinforcement, utilizing 8 mm diameter steel bars over a 30 cm length, planted at two different angles (90 and 45 degrees). The concrete column samples were subjected to uniaxial compressive load post-implantation. Results indicate that the implantation process generally led to an increase in the initial compressive strength of the concrete samples. Specifically, specimens with 30 cm reinforcement planted at distances of 55 mm and 35 mm exhibited an average strength increase of 23 % and 17 %, respectively.
10.34910/MCE.124.4
693.5
column
implantation
pull-out
steel fiber
bond
slip
https://engstroy.spbstu.ru/article/2023.124.4/
RAR
RUS
12405-12405
56434340300
0000-0002-5694-1737
Peter the Great St. Petersburg Polytechnic University
Usanova
Kseniia
plml@mail.ru
St. Petersburg, Russia
7801686579
0000-0001-7011-8213
Peter the Great Saint Petersburg Polytechnic University
Barabanschikov
Yuri
ugb@mail.ru
Polytechnicheskay, 29
Khalifa University of Science and Technology
Dixit
Saurav
sdixit@ricssbe.edu.in
Abu Dhabi, United Arab Emirates
Cementless binder based on high-calcium fly ash with calcium nitrate additive
Fly ash from Berezovskaya Thermal Power Plant, containing a lot of CaO, in combination with silica fume does not expand and exhibits the properties of a binder. However, the strength of this binder is low. The addition of Ca(NO3)2 significantly increases the strength of the binder. The work aims to study the effect of Ca(NO3)2 additive on the strength, heat of hydration, and phase composition of hydration products of the binder based on high-calcium fly ash and silica fume. The results of X-ray diffraction and Differential Thermal Analysis show that the main phases formed during the hydration of binder with the calcium nitrate additive in various dosages are lime, calcium hydroxide, ettringite, CSH(II) type silicates and calcium aluminosilicates, corresponding to such minerals as gismondine, yugavaralite, goosecreekite. When hardening in water, the residual amount of lime after 7 days is sharply reduced. An increase in the dosage of Ca(NO3)2 from 1.5 to 11.8 % leads to a decrease in the CaO content by almost 2 times. With an increase in the dosage of calcium nitrate, the content of portlandite noticeably decreases, and a significant increase in the amount of calcium hydroaluminosilicates, especially the composition of CAS2H4, is observed. A study of the heat release process showed that calcium nitrate greatly accelerates the process in the first 60 minutes of hydration. However, then the composition with the addition of Ca(NO3)2 is inferior in the rate of heat release to binder without the additive. When testing a mortar with polyfractional sand, the addition of Ca(NO3)2 more than doubled the compressive strength of the mortar.
10.34910/MCE.124.5
691.3
fly ash
microsilica
silica fume
early strength agent
calcium nitrate
X-ray diffraction analysis
strength
heat release
differential thermal analysis
heat of hydration
phase composition
https://engstroy.spbstu.ru/article/2023.124.5/
RAR
RUS
12406-12406
0000-0002-16579-0942
Bilad Alrafidain University College
Jawad
Saba
saba@bauc14.edu.iq
Diyala, Iraq
0000-0003-1304-0303
University of Baghdad
Karkush
Mahdi
mahdi_karkush@coeng.uobaghdad.edu.iq
Baghdad, Iraq
Shear strength and chemical properties of soft clayey soil treated with magnetized water
Design criteria of any type of foundation are mainly depending on the shear strength of the soil founded on/in it. In this research, investigation of the effect of magnetized water (MW) on shear strength and chemical properties of soft clayey soil was investigated. The shear strength of soft soil before and after treatment by MW was measured by an unconfined compressive strength test (UCST) and vane shear test (VST). Tap water used to treat the soft soil was modified by different magnetic field intensities (2000, 4000, 6000, and 8000 Gauss). Two-time intervals were used to conduct the shear strength tests for all intensities: first, after 7 days of treatment of the soil by MW, and second after 14 days. The circulating of MW through soft clayey soil samples for 7 days shows increasing the unconfined shear strength by 17, 39, 42, and 45% for soil treated with MW of intensity 2000, 4000, 6000, and 8000 G, respectively compared to the reference soil sample treated under the same conditions with tap water (TW). Increasing the duration of treatment up to 14 days showed increasing in the UCS of soft soil by 35, 49, 92, and 120% for soil treated with MW of intensity 2000, 4000, 6000, and 8000 G, respectively. On the other hand, the shear strength (Suv) measured by the vane shear device increased with increasing the intensity of the magnetic field for the same duration of treatment. The magnetized water technique can be considered as a promising and sustainable technology to be employed in geotechnical engineering to improving the geotechnical properties of soil.
10.34910/MCE.124.6
624.1
magnetized water
magnetic field
shear strength
soft soil
vane shear
unconfined compressive strength
https://engstroy.spbstu.ru/article/2023.124.6/
RAR
RUS
12407-12407
57196043891
0000-0002-8615-4208
Technical University of Varna
Zlateva
Penka
pzlateva@tu-varna.bg
Varna, Bulgaria
57205355298
0000-0003-2449-7173
Varna Free University "Chernorizets Hrabar"
Petkova-Slipets
Rositsa
rositsa.petkova@vfu.bg
Varna, Bulgaria
57196041130
0000-0002-6714-6480
Technical University of Varna
Yordanov
Krastin
krastin_yordanov@tu-varna.bg
Varna, Bulgaria
Properties of grey marl bricks with additions of rice husks
This article presents the results of experimental research on the impact of environmentally efficient materials developed on the basis of grey marl and sand with the addition of 3 % to 6 % of rice husk on the thermophysical characteristics: coefficient of thermal conductivity, specific heat capacity and thermal diffusivity. The thermal indicators are measured with a device based on the non-stationary method. The purpose of the research is to investigate the impact of a new type of a light natural organic additive material, the husk of rice grains, on the properties of the resulting composite. The task is to develop a new material which is both thermally efficient and eco-friendly. The results of the research show that the addition of rice husks reduces the coefficient of thermal conductivity by 42 %, of the thermal diffusivity by 38 %, and increases the specific heat capacity by 10 % compared to the reference sample.
10.34910/MCE.124.7
691
rice husks
grey marl
bricks
thermal properties
heat capacity
thermal conductivity
https://engstroy.spbstu.ru/article/2023.124.7/
RAR
RUS
12408-12408
Donbas National Academy of Civil Engineering and Architecture
Mushchanov
Volodymyr
volodymyr.mushchanov@mail.ru
Donbas National Academy of Civil Engineering and Architecture
Mushchanov
Alexander
a.v.mushchanov@donnasa.ru
Donbas National Academy of Civil Engineering and Architecture
Orzhekhovskii
Anatoly
aorzhehovskiy@bk.ru
Donbas National Academy of Civil Engineering and Architecture
Tsepliaev
Maxim
m.s.sepliaev@donnasa.ru
Optimum space frames with rectangular plans
In this article, the object of research is spatial framed systems, one of the most commonly used types of spatial structures. The main feature of the research is the expansion of proven design solutions to the area of large-span frames with rectangular plan with an aspect ratio of less than 1:2, which is an urgent research and practical task. In this regard, the main purpose of the research study is to establish a connection between the main parameters of the projected object (geometric characteristics, structural loads) and their metal intensity. The study was based on a number of research methods. We used the finite element method in the numerical study of the coating stability of rods loaded in the axial direction. The method of physical modeling helped in experimental studies of models and coatings of their elements. Finally, the method of optimal design, specifically the Nelder–Mead method, was used to find the basic shape of a structure with a long-span rectangular plan. Main results. First, the data from theoretical and experimental studies confirmed a decrease in the estimated length of the compressed elements by 5...25 % due to their partial pinching in the ball nodes-connectors. Secondly, we developed an optimal design algorithm of spatial frames with long-span rectangular plans with an aspect ratio of less than 1:2. It differs from the previously developed ones due to a clarification of the load-carrying ability of axially loaded rods from the stability condition and the project designer's advanced capabilities in terms of their shaping. It provides an opportunity to use clear correspondences at the trial design stage and to clarify the specific metal consumption to set the optimal geometric parameters of the projected structure. We found patterns that make it possible to design optimal material consumption flat and spatial structural forms of spatial frames on rectangular large-span plans with an aspect ratio of less than 1:2, while taking into account the refined bearing capacity of rods loaded in the axial direction. The results obtained make it possible to use a proven limited range of structural elements in the form of round-section rods and connecting elements (ball-and-socket plug-connectors).
10.34910/MCE.124.8
624.074.5
truss
truss structure
shape optimization
optimum design
structural optimization
https://engstroy.spbstu.ru/article/2023.124.8/
RAR
RUS
12409-12409
Peter the Great Saint Petersburg Polytechnic University
Ivanov
Ernest
ivanov-efimov.e@yandex.ru
Polytechnicheskay, 29
Peter the Great St. Petersburg Polytechnic University
Semenov
Kirill
kvsemenov@bk.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
7801686579
0000-0001-7011-8213
Peter the Great Saint Petersburg Polytechnic University
Barabanschikov
Yuri
ugb@mail.ru
Polytechnicheskay, 29
0000-0002-2908-4565
Peter the Great St. Petersburg Polytechnic University
Akimov
Stanislav
akimov_sv@spbstu.ru
St. Petersburg, Russia
Peter the Great St. Petersburg Polytechnic University
Kuleshin
Alexey
alex_kulesh4@mail.ru
St. Petersburg, Russian Federation
0000-0001-6384-4989
Peter the Great St. Petersburg Polytechnic University
Titov
Nikita
tns93@mail.ru
St. Petersburg, Russian Federation
Concrete heat liberation in thermal stressed state analysis
This paper presents the results of numerical studies of the temperature regime and the thermal stressed state of the reinforced concrete wall of the nuclear power plant foundation block during the construction period with continuous concreting at full height. Calculations were done both using the dependence of the change in heat liberation over time on the hardening temperature, according to the theory of I.D. Zaporozhets, as well as the experimental data. It is established that if Zaporozhets equation is used in calculations, the correction of heat release values should be performed in the first 45 hours of concrete hardening. In order to correct the theoretical values of the specific heat, the last one should be multiplied by the correction factor. The dependence of the factor on the time within the range of 4 to 45 hours is approximated with sufficient accuracy by the obtained fifth degree polynomial. The crack resistance of the structure was determined using a deformation criterion, taking into account the change in the ultimate elongation of concrete over time. In this particular case of concreting a structure it is shown that when the correction function is introduced into the calculation program there is no need to use thermal insulation. The direct economic effect, as well as the indirect one associated with the decrease in the construction period, allow avoiding the rise of the construction costs. It is proposed to use the developed methodology in practical calculations of thermal crack resistance of massive concrete and reinforced concrete structures during the construction period.
10.34910/MCE.124.9
691.32 + 691.328.1 + 691.335 + 624.042.5
concrete construction
reinforced concrete structures
construction period
thermo-stressed state
concrete heat liberation
https://engstroy.spbstu.ru/article/2023.124.9/
RAR
RUS
12410-12410
0009-0001-3191-5663
Peter the Great St. Petersburg Polytechnic University
Kokaya
David
kokaya.dv@edu.spbstu.ru
St. Petersburg, Russian Federation
Peter the Great St. Petersburg Polytechnic University
Zaborova
Daria
St. Petersburg, Russia
57189345350
0000-0002-8380-0067
Peter the Great St. Petersburg Polytechnic University
Koriakovtseva (Musorina)
Tatiana
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
Environmental analysis of residential exterior wall construction in temperate climate
With the growth of the construction industry market there is an urgent need to evaluate the use of building materials from the sustainable point of view. Product stage of construction materials has a significant negative impact on the environment. This work represents environmental assessment of the construction materials of a low-rise residential building located in the temperate climate zone. To conduct such an analysis, we used a comprehensive methodology, product life cycle assessment (LCA), complying with international standards ISO 14044 and ISO 14025. The global warming potentials were calculated for the building life cycle product stages (A1-A3) in the equivalent of the carbon dioxide emissions (CO2e). It was found that external walls have the greatest negative impact on the environment compared to other building elements. Production of construction materials for external wall structures is responsible for 45 % of the total CO2e emissions. Based on the performed calculations, alternative options for exterior wall construction are proposed. Heat losses were calculated for each type of enclosing structures, as well as greenhouse gas emissions from burning fuel for heating the building. It was found that an aerated concrete wall with ventilated facade has the least negative impact on the environment, even though heating a building with such an enclosing structure requires more energy than other wall options. Environmentally reasonable approach of the enclosing structure selection allowed a reduction of greenhouse gas emission by 16.7 %, from 402.85 tons to 335.65 tons CO2e.
10.34910/MCE.124.10
691
enclosing structures
global warming potential
production of building materials
greenhouse gas emissions
life cycle assessment
heat-losses
insulating materials
thermal transmittance
https://engstroy.spbstu.ru/article/2023.124.10/
RAR
RUS
12411-12411
57201190213
Peter the Great St. Petersburg Polytechnic University
Zotov
Dmitry
zotovdk@gmail.com
St. Petersburg, Russia
B-6662-2019
57204916380
0000-0002-6877-8420
Peter the Great Saint Petersburg Polytechnic University
Kozinetc
Galina
galina4410@yandex.ru
St. Petersburg, Russia
Peter the Great St. Petersburg Polytechnic University
Kozinetc
Pavel
pavelkozinetc@yandex.ru
St. Petersburg, Russia
0000-0003-0267-1505
Peter the Great St. Petersburg Polytechnic University
Chernov
Petr
PchelkaDragpet@mail.ru
St. Petersburg, Russian Federation
Peter the Great St. Petersburg Polytechnic University
Badenko
Vladimir
vbadenko@gmail.com
St. Petersburg, Russia
Digital models for retrospective analysis of the structure of currents in the Neva Bay
The Neva Bay is a body of water located between the delta of the Neva River and Kotlin Island. The goal of the study was to develop a method for numerical modeling of the shallow water equation in the Neva Bay, based on the finite element method. To achieve this goal, we solved a number of tasks. First, we selected characteristic periods in the history of the Neva Bay and formed numerical modeling options while determining boundary conditions. Secondly, we determined the geometric characteristics of the computational domain for modeling options and formed a finite element mesh for each of the options. Then, we found a numerical solution of hydrodynamic problems in terms of determining values of current velocity vectors. Finally, we conducted a comparative analysis of the results of solving the hydrodynamic problem of the structure of currents in the Neva Bay in different periods of history. The changes in the velocity field occurred because of the construction of the fairway and the dams for the Complex of flood protection structures (CFPS) in St. Petersburg. Today there is practically no water flow south of the Sea Canal. Water exchange between the Neva Bay and the Gulf of Finland is carried out due to culvert structures in the northern part of the CFPS and navigation facilities. The average flow of the Neva River during the calculation period did not change and was about 2500 m3/s (depends on the water level in Lake Ladoga); an increase in speeds occurs north of the Sea Canal.
10.34910/MCE.124.11
532.517
Neva Bay
Neva River
fairway
water area
hydrodynamic problem
finite element method
boundary conditions
anthropogenic impact
digital models
shallow water equation
velocity field
water exchange
hydrological regime
https://engstroy.spbstu.ru/article/2023.124.11/
RAR
RUS
12412-12412
AAU-2845-2020
57204362749
0000-0002-6289-325X
Peter the Great St. Petersburg Polytechnic University
Sergeev
Vitaliy
vicerector.sc@spbstu.ru
St. Petersburg, Russia
Peter the Great St. Petersburg Polytechnic University
Kotov
Evgeny
ekotov.cfd@gmail.com
St. Petersburg, Russia
Peter the Great St. Petersburg Polytechnic University
Horobrov
Svyatoslav
horobrov_sv@spbstu.ru
St. Petersburg, Russian Federation
Peter the Great Saint Petersburg Polytechnic University
Sabri
Mohanad Muaya
mohanad.m.sabri@gmail.com
Polytechnicheskay, 29
56227381900
0000-0003-2673-4566
Peter the Great Saint Petersburg Polytechnic University
Nemova
Darya
darya.nemova@gmail.com
Polytechnicheskay, 29
Hydrodynamic analysis of an unsteady pressureless filtration flow in earth cofferdams
Non-pressure filtration flows with a free surface, on which the fluid pressure is a constant and equal to the external atmospheric pressure, are essential characteristic of groundwater filtration through such hydraulic structures as, dams, water drawdowns, drains, foundations, and pits during their drain. The problems of fluid filtration in porous media are distinguished by a variety of boundary conditions for the desired complex filtration potential, geometric and physical characteristics of the filtration flow. Solving such problems by analytical methods becomes significantly more complicated due to the nonlinearity of the equation describing the filtration movement, the presence of a free surface and the geometry of the slopes of the structure. An alternative to their solution is the use of numerical methods for estimating unsteady free-flow filtration flows. This research is dedicated to developing a hydrodynamic analysis approach of the process of unsteady filtration by the methods of computational fluid dynamics on the example of a rectangular cofferdam of various configurations to apply the results in the design of hydraulic structures. Numerical modeling of an unsteady free-flow filtration in a rectangular cofferdam using the finite volume URANS method (ANSYS FLUENT) and finite-element method (PLAXIS 2D) was carried out. The depression curve evolution through time was obtained. Also, numerical results have been compared both with the experimental results and classical theoretical assumptions. Was found that the constructed models both for finite-volume and finite-element methods are consistent enough with the experimental data, and on the other hand, theoretical assumptions don’t agree with experimental and numerical data. Further, the filtration patterns in rectangular cofferdams with different drain positions were obtained using the developed calculation model, which allows to choose the most effective drain position for different purposes.
10.34910/MCE.124.12
66.067.1
soil cofferdam
unsteady fluid motion
numerical analysis
drawdown curve
ANSYS FLUENT
PLAXIS 2D
FEM
https://engstroy.spbstu.ru/article/2023.124.12/
RAR
RUS
12413-12413
JSC "Alekseevskdorstroy"
Bulanov
Pavel
pavel.bulanov1991@yandex.ru
Kazan State University of Architecture and Engineering
Vdovin
Yevgeniy
vdovin007@mail.ru
https://orcid.org/0000-0001-9680-6698
Kazan State University of Architecture and Engineering
Stroganov
Victor
svf08@mail.ru
Kazan, Russia
Increasing the level of aging stability of bitumes modified by kaolinite
During the literature review analysis, the main causes of bitumen binders aging were identified and the kaolinite modifier was proposed that have increased the bitumen aging resistance. The physical and mechanical properties of bitumen modified by kaolinite for the following indicators were studied: penetration at 25 °C, softening point, ductility at 0 °С, Fraas brittle point, dynamic viscosity at 105 °C, 135 °C and 165 °C. The bituminous binder aging was simulated in an RTFOT oven. The aging quality was determined by the softening point change, after aging in the RTFOT oven. The possibility of short-term aging reducing of modified bitumen at a kaolinite content of 2 % to 8 % by 12.5–28.6 % has been established. The characteristic peaks of bituminous binder aging: 1738, 1640, 1654, 1217, 1033 cm-1 were revealed by the IR spectroscopy method. It was established that the kaolinite introduction into bitumen has caused a significant decrease of aging processes, which has confirmed by the IR spectroscopy data: the peaks at 1640, 1564 and 1217 cm-1 almost completely have disappeared in the difference spectrum, and the intensity of carbonyl absorption band at 1738 cm-1 has decreased. The obtained experimental data confirmed the similarity of the processes described in previously published studies of other authors and the continuing research prospects in the direction of increasing the bitumen binders aging resistance at searching for new modifiers types and determining them optimal quantities.
10.34910/MCE.124.13
665.775.4
bitumen
kaolinite
aging
modification
clay mineral
https://engstroy.spbstu.ru/article/2023.124.13/