scholarly journals USE OF ASSEMBLY ASH IN THE COMPOSITION OF SOIL CEMENT

2021 ◽  
Vol 29 (2) ◽  
pp. 51-65
Author(s):  
N. Blaschuk ◽  
◽  
I. Maevska ◽  
M. Goncharuk ◽  
◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Soil Mass ◽  
Ash Content ◽  
Reinforced Soil ◽  
Optimal Composition ◽  
Soil Cement ◽  
Ash Removal ◽  
Practical Recommendations ◽  
Physical And Mechanical Characteristics

Іn this work, we searched for the optimal composition of soil cement containing different percentage of ash removal: from minor additives to the replacement of half the soil mass for ash. The search for the optimal composition was performed on the basis of experimental studies to determine the physical and mechanical characteristics.The use of soil cement with the addition of fly ash is proposed for the reinforcement of the bases by vertical reinforcing elements. In order to develop practical recommendations on the optimal composition of soil cement, a mathematical simulation of the work of reinforced soil cement fields was performed with the variation of the physical and mechanical characteristics of piles, depending on the ash content of the ash. . Plaxis software was used for numerical simulation. With a steady step of reinforcing elements, the properties of the soil-cement mass were studied, depending on the deformability of the piles.

Investigation of the Various Binders’ Effect on the Lime Binder Carbonate Hardening Process for its Use in Additive Technologies

2020 ◽  
Vol 1011 ◽  
pp. 123-129
Author(s):  
Alexander Bakhtin ◽  
Nikolay Lyubomirskiy ◽  
Tamara Bakhtina ◽  
Vitaliy Nikolaenko
Keyword(s):  
Inkjet Printing ◽  
Mass Fraction ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Hydrated Lime ◽  
Additive Technologies ◽  
High Concentration ◽  
Hardening Process ◽  
Materials Used ◽  
Physical And Mechanical Characteristics

The obtaining carbonized material experimental studies’ results based on lime carbonate systems by 3D inkjet printing are presented. Some types of materials used as binders for inorganic binders have been studied. An effective method of hardening the model obtained in the 3D printing process is determined. The physical and mechanical characteristics of the prototypes hardened in the carbon dioxide medium or high concentration are determined. It was found that artificial carbonization of the samples obtained on various types of binders for 90 min contributes to the formation of a fairly strong structure of insoluble calcium carbonate, the hydrated lime carbonation product, and the carbonization degree depends on the type of binder and its mass fraction in the solution. The most effective types of binders were selected and the optimal content of the studied binders in the solution was determined.

Potential for pellet manufacturing with wood waste from construction in Costa Rica

2019 ◽  
Vol 38 (8) ◽  
pp. 886-895 ◽  
Author(s):  
Monzerrath Rivera-Tenorio ◽  
Roger Moya
Keyword(s):  
Costa Rica ◽  
Moisture Content ◽  
Mechanical Characteristics ◽  
Calorific Value ◽  
Ash Content ◽  
Wood Waste ◽  
Construction Sector ◽  
Pellet Quality ◽  
Energy Potential ◽  
Physical And Mechanical Characteristics

The construction sector in Costa Rica produces approximately 100 kg per square meter of residues, of which wood waste comprises 30%. Utilization of these wastes is still limited, but options are being sought and biomass is one of them. The aim of this work was to evaluate the characteristics of biomass produced from wood waste from construction, its energy potential, and its appropriateness for pellet manufacturing by determining its energy, physical, and mechanical characteristics. It was found that wood waste from construction is composed of different species with densities below 0.5 g/cm3, 26% moisture content, and 10% ash content; contamination with cement and nails can reach 6%. The process of pellet manufacturing can adapt adequately to using wood waste from construction, with an efficiency or yielding of 33%. Pellets presented a calorific value of 19573 kJ/kg, a bulk density of 1.25 g/cm3, an apparent density of 700 kg/m3, a failure force in compression of 467 N, and durability of 94.28%. According to different standards, the results obtained for biomass from wood waste are within the range established for pellet quality; therefore, wood waste from construction can be used to produce pellets, despite the disadvantage of it presenting high ash content.

Composite Polymer Mesh For Masonry

2019 ◽  
pp. 15-19
Keyword(s):  
Strain State ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Structural Elements ◽  
Composite Polymer ◽  
Performance Technology ◽  
Different Types ◽  
Composite Grids ◽  
And Performance ◽  
Physical And Mechanical Characteristics

With the development and introduction of technologies for the production of composite materials for construction purposes in Russia appeared composite flexible ties, anchors, fittings, etc. These materials and products are not fundamentally new and have previously been studied for use for reinforcing concrete or structural elements. However, for increasing the bearing capacity of stone structures as masonry meshes they were practically not used, while masonry mesh is one of the most demanded materials in construction. The article presents experimental studies of composite meshes of different types and performance technology used in masonry. Experimentally substantiated and normalized values of physical and mechanical characteristics of rods for composite polymer grids are obtained. The evaluation of efficiency of composite meshes in masonry is made, the values of crack forming and rupture loads are determined, the peculiarities of the stress-strain state of composite grids as flexible ties are revealed, the fields of application are formulated.

scholarly journals Waterproofing material for protection of underground structures

2019 ◽  
Vol 97 ◽  
pp. 02008
Author(s):  
Olga Lyapidevskaya
Keyword(s):  
Crack Resistance ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Ethylene Vinyl Acetate ◽  
Hard Coatings ◽  
Optimal Composition ◽  
Underground Structures ◽  
High Elasticity ◽  
Main Disadvantage ◽  
Physical And Mechanical Characteristics

The article deals with the problem of increasing the durability of underground and buried buildings. One of the methods of solving this problem is ensuring the reliable protection of underground structures from the effects of water of different origin. Among the existing waterproofing coatings, mineral-based compositions are the most effective. However, the main disadvantage of such systems is the low crack resistance of hard coatings, which limits their applicability. We have made an attempt to develop a cement-based waterproofing material that would have high elasticity, strength, crack resistance and adhesion to a concrete base. We have conducted studies to justify the possibility of obtaining an effective waterproofing material by including microsilica and ethylene vinyl acetate in the mix. The optimal composition of the material was worked out. On the basis of the experimental data, the main physical and mechanical properties of the material were established. Based on the obtained results, it was found that the resulting material had high physical and mechanical characteristics and could be recommended for the protection of concrete structures used in underground construction.

Water Absorption Effect on the Propagation Velocity of Normal Waves in Composite Rebars

2019 ◽  
Vol 970 ◽  
pp. 202-209
Author(s):  
Olga V. Muravieva ◽  
Robert R. Khasanov ◽  
Viktor A. Strizhak ◽  
Sergey S. Mkrtchyan
Keyword(s):  
Water Absorption ◽  
Propagation Velocity ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Absorption Effect ◽  
Acoustic Waveguide ◽  
Torsional Waves ◽  
Water Absorption Effect ◽  
Waveguide Method ◽  
Physical And Mechanical Characteristics

The article proposes the use of the acoustic waveguide method with normal Pochhammer waves to estimate the water absorption of composite fiberglass rebars. The results of experimental studies on the water absorption and temperature influence on the propagation velocity of rod and torsional waves in composite rebars samples with different physical and mechanical characteristics are presented. The sensitivity of the wave velocity parameter to water absorption and temperature fluctuations is estimated. The proposed acoustic waveguide method is characterized by high accuracy, reliability and efficiency.

scholarly journals Управление физико-механическими характеристиками бетона за счет варьирования высоты и шага технологических выступов хомутов виброцентрифугирующих устройств

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Cross Section ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Technological Parameters ◽  
Axial Tensile ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

Для регулирования вариатропной структуры центрифугированных изделий авторы данной статьи совместили процесс центрифугирования с вибрированием. Во время эксперимента вибрации формы обеспечивались за счет надетых на валы установки хомутов. Представлена авторская экспериментальная установка для создания виброцентрифугированных образцов кольцевого сечения с вариатропной структурой, а также способ их изготовления. Выделены технологические параметры вибрирования, которые оказывали наиболее значимое влияние на характеристики виброцентрифугированного бетона, конструкций и изделий из него. В опытах варьировались высота технологических выступов хомутов и шаг между ними. Исследовалось влияние этих факторов на физико-механические характеристики бетона: плотность; кубиковая прочность на сжатие; призменная прочность на сжатие; прочность на растяжение при изгибе; прочность на осевое растяжение. Приведен анализ результатов экспериментальных исследований и получены следующие физико-механические характеристики виброцентрифугированных бетонов, изготовленных с использованием хомутов: лучшие – с высотой технологических выступов 5 мм и шагом между ними 30 мм, самый низкий показатель – соответственно 2,5 мм при любом шаге. Ключевые слова: виброцентрифугированный бетон, физико-механические характеристики, прочность при сжатии, плотность, бетонная смесь, центрифугирование, прочность при изгибе To regulate the variatropic structure of centrifuged products, the authors of this article combined the process of centrifugation with vibration. During the experiment, vibrations of the mold were provided with clamps set on the shafts of the installation. The author's experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure, as well as a method for their manufacture is presented. The technological parameters of vibration, which had the most significant effect on the characteristics of vibrocentrifuged concrete, structures and products made of it, were identified. In the experiments, the height of the technological protrusions of the clamps and the pitch between them were varied. The influence of these factors on the physical and mechanical characteristics of concrete was investigated: density; cube compressive strength; prismatic compressive strength; bending tensile strength; axial tensile strength. Analysis of the results of experimental studies is given and the following physical and mechanical characteristics of vibrocentrifuged concretes made using clamps have been obtained: the best ones with a height of technological protrusions of 5 mm and a step between them of 30 mm, the lowest indicator is, respectively, 2.5 mm at any step. Keywords: vibrocentrifuged concrete, physical and mechanical characteristics, compressive strength, density, concrete mix, centrifugation, flexural strength

scholarly journals Determining the mechanical characteristics of composite materials reinforced with woven preforms

2021 ◽  
Vol 1 (7 (109)) ◽  
pp. 41-50
Author(s):  
Maryna Shevtsova ◽  
Andrii Kondratiev ◽  
Oleksii Andrieiev
Keyword(s):  
Composite Materials ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Compression Tests ◽  
Study Program ◽  
Good Convergence ◽  
Variable Nature ◽  
Rod System ◽  
Rod Model ◽  
Physical And Mechanical Characteristics

Reduction of the complexity of production of articles from composite materials is largely ensured by the use of reinforcing semi-finished products in which fibers pre-form a framework. Among all the variety of reinforcing systems, woven sleeves (preforms) occupy a special place. The high degree of deformability in a nonimpregnated condition makes it possible to lay this reinforcement on any surface without folds and cuts that provide preservation of strand continuity. This advantage of woven sleeves is accompanied by a change in local reinforcement angles and, consequently, the variable nature of physical and mechanical characteristics of the curved part surface. A method for calculating physical and mechanical characteristics of the composite based on preforms at any point of the part depending on the pattern of laying strands on a curved surface has been developed. The possibility of application of the rod model of the composite to describe physical and mechanical characteristics of the composite material with a woven reinforcement was analyzed. The model essence consists in that the composite is modeled by a diamond-shaped rod system. The rhombus sides serve as fibers and the diagonals as the binder. To verify the theoretical results and substantiate practical recommendations, a series of experimental studies were performed based on the formation of material specimens from two types of woven sleeves with different reinforcement angles. The experimental study program included tensile, bending, and compression tests. A fairly good convergence of theoretical and experimental data was obtained. For example, a square of the correlation coefficient was not less than 0.95 for the modulus of elasticity, not less than 0.8 for the Poisson's ratio, and not less than 0.9 for tensile and compressive strengths. This is the rationale for using the rod model to describe the considered class of composites. The use of the developed procedure will make it possible to increase the perfection of the considered class of designs and obtain rational parameters of the process of their manufacture.

scholarly journals DURABILITY ASSESSMENT OF BENDING STRUCTURES MADE OF NONLINEAR ELASTIC MATERIAL

2020 ◽  
Vol 16 (4) ◽  
pp. 80-85
Author(s):  
Vladilen Petrov ◽  
Roman Mishchenko ◽  
Dmitry Pimenov
Keyword(s):  
Mathematical Model ◽  
Mechanical Characteristics ◽  
Negative Impact ◽  
Experimental Studies ◽  
Field Tests ◽  
Corrosive Media ◽  
Nonlinear Elastic Material ◽  
Durability Assessment ◽  
Nonlinear Elastic ◽  
Physical And Mechanical Characteristics

Experimental studies and field tests indicate that the effect of corrosive media leads to significant changes in the physical and mechanical characteristics of structural materials. The article proposes a mathematical model that allows predicting the negative impact of aggressive media and assessing the durability of bent structures.

scholarly journals Influence of Parameters the Wall on Reinforced Soil Segmental Walls

2017 ◽  
Vol 3 (6) ◽  
pp. 395-411
Author(s):  
Baaziz Salah Eddine ◽  
Mellas Mekki
Keyword(s):  
Mechanical Characteristics ◽  
Numerical Study ◽  
Experimental Studies ◽  
Retaining Walls ◽  
Reinforced Soil ◽  
Remarkable Effect ◽  
Geosynthetic Reinforced Soil ◽  
Properties Of Materials ◽  
Lateral Displacements ◽  
Wall Geometry

The behaviour of retaining walls in geosynthetic reinforced soil is complex and requires studies and research to understand the mechanisms of rupture, the behaviour of the reinforcements in the soil and the behaviour of the main elements of the system: reinforcement-wall-soil. Several researches have been done on the use of geosynthetics as backfill massive reinforcement material (experimental studies, numerical analysis, reduced models ...). This parametric study was conducted to investigate the influence of numerical parameters of the wall which confront us in the projects, on the behaviour of walls on reinforced soil segmental walls.  A 3.6m high wall is composed of modular blocks of earth sand reinforced with four geogrids layers was modelled. The properties of materials, the wall geometry, and the boundary conditions will be explained later. The finite difference computer program FLAC3D was used in this study. The results of this numerical study allowed to deduce the importance of each parameter of the wall selected for the behaviour of retaining walls in soil reinforced by geogrid. The inclination of wall "W" is of great importance for the calculation of retaining walls in modular blocks and can provide an important contribution to the horizontal balance of this type walls. The value of lateral displacements of the facing tends to continuously decrease with the increase of "W". More the wall is inclined plus the horizontal stresses behind the wall and values of the tensile stress in the layers of geogrid "T" decrease in an expressive manner. The dimensions of modular blocks (types) and the mechanical characteristics of modular blocks (category) have a remarkable effect on the calculation of retaining walls in modular blocks reinforced with layers of geogrid.

Sign in / Sign up

Export Citation Format

Share Document