scholarly journals The deformability of compressed concrete elements strengthened with FRCM composite materials

2013 ◽  
Vol 12 (1) ◽  
pp. 163-170
Author(s):  
Tomasz Trapko
Keyword(s):  
Composite Materials ◽  
Experimental Studies ◽  
Influence Of Temperature ◽  
Cementitious Matrix ◽  
Concrete Elements

In the paper the results of experimental studies performed on compressed concrete elements strengthened with composite fabric of FRCM (Fibre Reinforced Cementitious Matrix) technology are presented. In the studies the influence of temperature, the number of composite fabric layers and the length of ending overlap on the value and distribution of circumferential limit strains was analyzed.

Calculation Of Carbon Fiber Anchors For Pull-Out And Shear When Installing External Reinforcement Systems

2020 ◽  
pp. 4-8
Keyword(s):  
Composite Materials ◽  
Carbon Fibers ◽  
Experimental Studies ◽  
The Body ◽  
Carbon Fibres ◽  
Calculation Methods ◽  
Regulatory Documents ◽  
Pull Out ◽  
External Reinforcement ◽  
Concrete Elements

The operation of external reinforcement systems based on carbon fibers when strengthening normal and inclined sections of bending reinforced concrete elements depends largely on the anchoring to the body of the reinforced structure. In addition to adhesion, one of the options for ensuring the required level of anchoring of external reinforcement is the installation of anchoring elements, including those based on carbon fibers. This article discusses the calculation of anchors based on carbon fibres used in the arrangement of the external reinforcement system. Two principles of anchor arrangement operation are highlighted: for shear and for pull-out. Separate design provisions have been developed for each, taking into account the parameters of anchoring elements and the nature of the destruction obtained during experimental studies. The proposed calculation methods are based on experimental studies of both bending elements reinforced by external reinforcement systems and directly anchoring elements. In addition, the development of these methods takes into account the provisions available in the regulatory documents on the calculation of anchors and composite materials.

Effect of Wood Filler Concentration on Physical and Mechanical Properties of PLA-Based Composites

2021 ◽  
Vol 887 ◽  
pp. 110-115
Author(s):  
G.A. Sabirova ◽  
R.R. Safin ◽  
N.R. Galyavetdinov
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Composite Materials ◽  
Impact Strength ◽  
Wood Flour ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Filler Concentration ◽  
High Concentration

This paper presents the findings of experimental studies of the physical and mechanical properties of wood-filled composites based on polylactide (PLA) and vegetable filler in the form of wood flour (WF) thermally modified at 200-240 °C. It also reveals the dependence of the tensile strength, impact strength, bending elastic modulus, and density of composites on the amount of wood filler and the temperature of its thermal pre-modification. We established that an increase in the concentration of the introduced filler and the degree of its heat treatment results in a decrease of the tensile strength, impact strength and density of composite materials, while with a lower binder content, thermal modification at 200 °C has a positive effect on bending elastic modulus. We also found that 40 % content of a wood filler heated to 200 °C is sufficient to maintain relatively high physical and mechanical properties of composite materials. With a higher content of a wood filler, the cost can be reduced but the quality of products made of this material may significantly deteriorate. However, depending on the application and the life cycle of this product, it is possible to develop a formulation that includes a high concentration of filler.

scholarly journals FEA and Experimental Studies of Adaptive Composite Materials with SMA Wires

2008 ◽  
Author(s):  
K. Kanas ◽  
C. Lekakou ◽  
N. Vrellos ◽  
Alexander M. Korsunsky
Keyword(s):  
Composite Materials ◽  
Experimental Studies ◽  
Adaptive Composite

scholarly journals Effects of Concrete Core Technological Defects on the Strength of Tube Confined Concrete Elements

2018 ◽  
Vol 7 (3.2) ◽  
pp. 376
Author(s):  
Oleksandr Semko ◽  
Olga Gukasian ◽  
Serhii Skliarenko
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Fracture Pattern ◽  
Confined Concrete ◽  
Concrete Core ◽  
Different Types ◽  
Technological Defects ◽  
Concrete Elements ◽  
Core Production ◽  
Physical And Mechanical Characteristics

The paper sums up a series of experimental studies describing the influence of most types of concreting common defects, such as core weakening: weak compression inclusions, voids, height heterogeneity of concrete. The basis of the experimental study is the research on the concrete core production conditions influence on tube confined concrete elements and the change in physical and mechanical characteristics of the elements. The concrete strength is estimated based on the results of the study of specially shaped samples with given dimensions. According to the results of concreting samples with different types of modeled defects (abnormalities) inspection, the most dangerous damages of the concrete core were identified and different variants of the height strength retrogression of the elements under study were analyzed. As a result, the degree and type of damage to the tube confined concrete elements core of the samples, which affect the fracture pattern, was established. 

scholarly journals Physico-technical approach to design of composites from mineral and polymer technogenic resources

2015 ◽  
Vol 1 ◽  
pp. 162 ◽  
Author(s):  
Gotfrīds Noviks
Keyword(s):  
Composite Materials ◽  
Experimental Studies ◽  
Process Efficiency ◽  
Operating Characteristics ◽  
Forming Process ◽  
Polymer Waste ◽  
Composite Forming ◽  
Different Types ◽  
Low Levels

<p class="R-AbstractKeywords"><span lang="EN-US">Artificial composite materials are currently being produced in large quantities, they are diverse and they are widely used in the economy. There have been extensive theoretical and experimental studies of different types of components, developed the calculation methods of composites production with predefined properties.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">At the same time industry produces a lot of mineral and polymer waste, which are practically technogenic resources, but their use is currently at quite low levels. The paper examines the possibilities to use technogenic resources- mineral (such as ash and clay) and organic (polymers -PET containers) for producing qualitative composite materials. For this purpose theoretical analysis and calculations of the physical properties of components and process parameters that determine the operating characteristics of the composite material were carried out.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">Composite-forming process efficiency determinative parameters were analysed: adhesion, the specific surface energy, specific free surface, adsorption capacity and the degree of dispersion of the particles.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">The role of external factors in processing of composite were examined – temperature, concentration of components.</span></p><p class="R-AbstractKeywords"><span lang="EN-US">The characteristics of prepared samples of composites showed the possibility to use these waste for the development of qualitative products for different purposes.</span></p>

scholarly journals Optimizing of system "column-cfrp lamellas" with the strengthening of civil structures

2021 ◽  
Vol 9 (1) ◽  
pp. 1-5
Author(s):  
Irina Mayackaya ◽  
Batyr Yazyev ◽  
Anastasia Fedchenko ◽  
Denis Demchenko
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Concrete Structures ◽  
Polymeric Composite ◽  
Concrete Columns ◽  
Reinforced Concrete Structures ◽  
Structural Elements ◽  
Civil Structures ◽  
Concrete Elements

Reinforced concrete elements of structures in the form of columns, beams, ceilings are widely used in the construction of buildings and structures of industrial and civil construction. In most cases, the columns serve as supports for other building elements, for example, crossbars, slabs, girders, beams. One of the cycles of the work of reinforced concrete structures is the state of their repair and reconstruction, including the stages of strengthening the elements. There is a problem of strengthening of reinforced concrete columns. The article deals with the issue of reinforcing columns and other structural elements having a cylindrical surface, with polymeric composite materials in the form of carbon fiber lamellae. The use of composite materials allows to increase the service life and strength of reinforced concrete structures used in construction.

Influence of Temperature and Relative Humidity on Perm-Selectivity of PET Packaging Film

2011 ◽  
Vol 295-297 ◽  
pp. 1206-1210
Author(s):  
Yan Feng Guo ◽  
Xian Ping Ma ◽  
Yu Yan ◽  
Yun Gang Fu
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Experimental Studies ◽  
Thermodynamic Temperature ◽  
Packaging Film ◽  
Influence Of Temperature ◽  
Carbon Dioxide Gas ◽  
Pet Film ◽  
Pet Films ◽  
Temperature Water

The main feature of this article is the investigation on the influence of temperature, relative humidity, film thickness on permeability of PET packaging film, the analysis of perm-selectivity of the packaging films for oxygen gas and carbon dioxide gas, and the evaluation on experimental formulas of water vapor, O2 and CO2 gas permeating rates on the basis of gas molecular osmotic reaction kinetics and regression analysis. The comparison between experimental studies and calculation indicates that: (1) with increment of ambient temperature water vapor, O2 and CO2 permeating rate of PET films and PET/Al film also rise, and the logarithm of water vapor, O2 and CO2 gas permeating rates has linear relation with the reciprocal of thermodynamic temperature, and (2) the influence of relative humidity on water vapor permeating rate of PET film with thickness 12µm is the least, and that of PET film with thickness 20µm and PET/Al film with thickness 18µm is a little obvious. (3) The PET films hold remarkable perm-selectivity for O2 and CO2 gas, and CO2 gas permeating rate is about two times of O2 gas, yet O2 and CO2 gas permeating rates of PET/Al film are both very low and have small difference, so the PET/Al film has better barrier performance than the PET film.

CORRELATION DEPENDENCES OF THE BENDING STRENGTH OF POLYMER COMPOSITE MATERIALS MODIFIED IN A MICROWAVE ELECTROMAGNETIC FIELD ON THE MOISTURE CONTENT DURING EXPOSURE IN FULL-SCALE CONDITIONS

2021 ◽  
pp. 3-9
Author(s):  
I. V. Zlobina ◽  
I. S. Katsuba
Keyword(s):  
Electromagnetic Field ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Moisture Content ◽  
Bending Strength ◽  
Climatic Factors ◽  
Experimental Studies ◽  
Three Point Bending ◽  
Treated Carbon ◽  
Control Samples

Experimental studies of the influence of external climatic factors, taking into account exposure, on the change in the bending strength of control and microwave – treated carbon and fiberglass samples in the cured state were performed. An increase in the limit stresses of three – point bending of experimental carbon fiber samples compared to the control ones was found by 7…12 %, and fiberglassby 4…7 %. It is shown that with an increase in exposure to 14 months, the strength of control samples of carbon and fiberglass decreases by an average of 10 %. At the same time, the strength of the prototypes is reduced only by 4.4 %. With an increase in the moisture content of both control and experimental samples, a decrease in their strength is observed. In this case, the linear correlation is average (from– 0.44 to – 0.615). It is established that for experimental samples, the influence of the amount of absorbed moisture on the strength is manifested to a much lesser extent. For carbon fiber, the reduction is 16.6 %, for fiberglass – 12 %.

Non-Wood Lignocellulosic Composites

2014 ◽  
pp. 281-319 ◽  
Author(s):  
Marius C. Barbu ◽  
Roman Reh ◽  
Ayfer Dönmez Çavdar
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Experimental Studies ◽  
Raw Material ◽  
Synthetic Fiber ◽  
Plant Fibers ◽  
Labor Conditions ◽  
Appropriate Treatment ◽  
Manufacturing Technologies ◽  
Cellulose Materials

It would seem that with appropriate treatment almost any agricultural residue may be used as a suitable raw material for the wood-based panels like particle- and fiberboard production. The literature on wood-ligno-cellulose plant composite boards highlights steady interest for the design of new structures and technologies towards products for special applications with higher physical-mechanical properties at relatively low prices. Experimental studies have revealed particular aspects related to the structural composition of ligno-cellulose materials, such as the ratio between the different composing elements, their compatibility, and the types and characteristics of the used resins. Various technologies have been developed for designing and processing composite materials by pressing, extrusion, airflow forming, dry, half-dry, and wet processes, including thermal, chemical, thermo-chemical, thermo-chemo-mechanical treatments, etc. Researchers have undertaken to determine the manufacturing parameters and the physical-mechanical properties of the composite boards and to compare them with the standard PB, MDF, HB, SB made from single-raw material (wood). A great emphasis is placed on the processability of the ligno-cellulose composite boards by classical methods, by modified manufacturing processes, on the types of tools and processing equipment, the automation of the manufacturing technologies, the specific labor conditions, etc. The combinations of wood and plant fibers are successful, since there is obvious compatibility between the macro- and microscopic structures, their chemical composition, and the relatively low manufacturing costs and high performances, as compared to synthetic fiber-based composite materials.

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