Composite Material for the Manufacture of Plastic Sleepers

2021 ◽  
Vol 899 ◽  
pp. 150-157
Author(s):  
Valerii I. Kondrashchenko ◽  
C. Wang ◽  
Tatyana A. Matseevich ◽  
Andrey A. Askadskii
Keyword(s):  
Composite Material ◽  
Thermal Expansion ◽  
Reinforced Concrete ◽  
Composite Materials ◽  
Polyvinyl Chloride ◽  
Linear Thermal Expansion ◽  
Polymer Binder ◽  
Internal Stresses ◽  
Mineral Filler ◽  
Railway Transport

The composite materials intended for the manufacture of plastic sleepers were produced, which significantly differ from the materials widely used in railway transport of wooden and reinforced concrete sleepers. The coefficients of linear thermal expansion of the obtained materials are significantly lower. Polyvinyl chloride is used as a polymer binder, and the filler is a mixture of softwood flour with the mineral filler in the form of finely ground chalk. It was shown that by varying the content of the components of the composite, a change in its density is achieved by 19%, and the change in the value of the coefficient of linear thermal expansion depends on the temperature and relaxation of internal stresses in the samples, varying by 18.7 times – from 288.4·10-6 to 15.4·10-6 °C -1.

scholarly journals EXTERNAL REINFORCEMENT OF CONCRETE STRUCTURES USING COMPOSITE MATERIALS

2018 ◽  
pp. 92-100
Author(s):  
V. I. Rimshin ◽  
S. I. Merkulov
Keyword(s):  
Composite Material ◽  
Reinforced Concrete ◽  
Composite Materials ◽  
Concrete Structure ◽  
Structural Reliability ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Reinforced Beams ◽  
External Reinforcement

The paper describes the main directions of non-metallic composite application in concrete reinforcement. The development routes of the structural analysis with composite reinforcement are formulated. The reinforced concrete structure combines the elastic reinforcement element with an adhesive composition having inelastic properties. It is shown that the structural reliability is ensured by adhesion of composite core reinforcement to the concrete. When performing external reinforcement of composite materials, it is necessary to ensure the joint operation of reinforcing elements and the main structure. Today, design methods of concrete structure reinforcement with composite materials do not take into account shear strains in the contact seam. Adhesion of composite material to concrete is indirectly assessed by introducing the service factor of composite material when its design resistance is assigned. Experimental studies concern concrete structures  reinforced by bent elements with external reinforcement made of various composite materials. Reinforced concrete beams with A500 and A600 class reinforcement are considered. Test beams are reinforced with fiberglass, coal and carbonates canvases. Some of test beams have U-shaped anchors at the ends and are made of composite materials. Reinforced beams fracture by different schemes: composite peeling due to the adhesive destruction in the area of formation of normal and inclined cracks, compositepeeling with the destruction of protective layer, composite rupture. A part of reinforced concrete beams before the reinforcement are cracked in the stretched zone. Cracks do not affect the load-bearing capacity of reinforced beams. 

Environmental Compatibility of Carbon Reinforced Concrete: Irrigated Construction Elements

2019 ◽  
Vol 809 ◽  
pp. 314-319 ◽  
Author(s):  
Lia Weiler ◽  
Anya Vollpracht
Keyword(s):  
Heavy Metal ◽  
Composite Material ◽  
Reinforced Concrete ◽  
Composite Materials ◽  
Building Materials ◽  
Outdoor Exposure ◽  
Leaching Behavior ◽  
Environmental Compatibility ◽  
Materials Research ◽  
Harmful Substances

To foster a sustainable deployment of the innovative composite material ‘carbon concrete composite’ in the building sector, it is necessary to ensure its resource efficiency and environmental compatibility. The Institute for Building Materials Research of the RWTH Aachen University is therefore investigating the leaching behavior of this material, especially for the case of irrigated façade elements. Laboratory and outdoor exposure tests are run to determine and assess the heavy metal and trace element emissions by leaching. Feasible interconnections between laboratory and outdoor examinations can be used to develop a faster testing of future composite materials. Current results show no critical release of environmental harmful substances from carbon concrete composite.

scholarly journals MONITORING BY FIBER OPTICAL SENSORS OF RELIABILITY OF OPERATION OF BUILDING STRUCTURES WITH EXTERNAL COMPOSITE REINFORCEMENT

2020 ◽  
pp. 54-64
Author(s):  
M. Yu. Fedotov ◽  
O. N. Budadin ◽  
S. O. Kozelskaya ◽  
I. G. Ovchinnikov ◽  
I. S. Shelemba
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Optical Sensors ◽  
Linear Thermal Expansion ◽  
Actual Condition ◽  
Actual State ◽  
Building Structures ◽  
Destructive Testing ◽  
External Reinforcement ◽  
Significant Difference

This article describes of the actual state of building structures by the example of structures of reinforced concrete and metal bridges. It is shown that a high degree of wear of artificial structures leads to the need for a reliable assessment of their actual condition using modern methods and means of non-destructive testing and diagnostics, as well as strengthening exploited structures with polymer composite materials. The results of researches on fiber-optic monitoring and strengthening of bridge spans with composite materials based on domestic and foreign carbon reinforcing fillers and epoxy polymer matrices are presented. It has been experimentally shown that for reinforced concrete structures it is advisable to use composite strengthening systems using external reinforcement installed directly on the damaged object by contact molding. For metal structures, this approach is not applicable due to a significant difference in the coefficients of linear thermal expansion of composites and metals. In this case, an amplification system based on prefabricated composite truss systems made by autoclave and unautoclave molding can be applied. The obtained research results also indicate the advisability of joint use of monitoring systems and strengthening of damaged bridge structures by composites.

scholarly journals Aging of Polymer Composites in Extremely Cold Climates

2020 ◽  
pp. 41-51 ◽  
Author(s):  
O.V. Startsev ◽  
M. P. Lebedev ◽  
A.K. Kychkin
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Composite Materials ◽  
Solar Radiation ◽  
Solid Phase ◽  
Climatic Conditions ◽  
Internal Stresses ◽  
Cold Climates ◽  
Reinforcing Fibers ◽  
Effects Of Temperature

A review of studies of effects of temperature, moisture, solar radiation, and other aggressive environmental factors on the properties of polymer composite materials are presented to substantiate the mechanism of their aging in extremely cold climates. It has been shown that composites develop internal stresses caused by unequal thermal expansion of reinforcing fibers and polymer matrices. These internal stresses cause the occurrence of microcracks, their coalescence, and formation of macro-damages in the bulk of the binder or at the interface with fibers. Fiberglass, carbon fiber, and other reinforced materials exposed to climatic conditions can accumulate water in pores and capillaries, which can turn into a solid phase at temperatures below 0 °C and increase internal stresses. Even in cold climates, the surface of materials undergoes destruction and microcracking under the impacts of UV components of solar radiation, thus increasing the number of sources of internal stresses. The mechanical properties of composite materials deteriorate under the effects of seasonal and daily thermal cycles.

scholarly journals Thermal analysis of Kevlar/basalt reinforced hybrid polymer composite

2021 ◽  
Author(s):  
V Ramesh ◽  
P Anand
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Composite Materials ◽  
Hybrid Composite ◽  
Hybrid Composites ◽  
Thermo Gravimetric Analysis ◽  
Linear Thermal Expansion ◽  
Thermal Conductance ◽  
Mechanical And Thermal Properties ◽  
Gravimetric Analysis

Abstract Use of lightweight composite materials in automobile applications such as doors, bonnets, and bumpers and also the utilization of composite materials in building insulations require superior mechanical and thermal properties. This study attempts to determine the thermal conductivity, linear thermal expansion coefficient, heat deflection temperature and thermo gravimetric analysis of hybrid composite containing reinforcement fibers stacked in seven different combinations in an epoxy matrix as per ASTM standards. Each composite contained two different fibre materials, i.e., Kevlar and basalt. The study revealed that the stacked layers of basalt fibers had more influence on the thermal properties. It was observed that the hybrid composite made of least quantity layers of Kevlar and most of basalt exhibited the maximum thermal conductance of 0.219W/mK, while with vice versa laminate developed 0.191W/mK which was least thermal conductance. The composition prepared by made Kevlar as core layer and basalt as its outer layers exhibited coefficient of linear thermal expansion above 11.5x10-6/oC. Maximum decomposition weight loss of 76.92% occurred in the composition prepared by keeping basalt as core and Kevlar as outer layer. The differential thermal graph showed that the said hybrid composite exhibited the peak decomposition rate of 1wt.%/oC. The thermal properties of the laminate prepared by keeping two layers of Kevlar sandwiched between the basalt were excellent when compared to other six hybrid composites investigated in this study.

Study of the Composite Materials Optimal Structure Containing a Hollow Aluminum and Silica Microsphere Dependence on Humidity

2020 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Atyaksheva ◽  
Yermek Sarsikeyev ◽  
Anastasia Atyaksheva ◽  
Olga Galtseva ◽  
Alexander Rogachev
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Strength Function ◽  
Theory And Practice ◽  
Optimal Structure ◽  
Optimal Size ◽  
Structure And Properties ◽  
Power Functions ◽  
Silica Microsphere ◽  
Heat Engineering

Aims:: The main goals of this research are exploration of energy-efficient building materials when replacing natural materials with industrial waste and development of the theory and practice of obtaining light and ultra-light gravel materials based on mineral binders and waste dump ash and slag mixtures of hydraulic removal. Background.: Experimental data on the conditions of formation of gravel materials containing hollow aluminum and silica microsphere with opportunity of receipt of optimum structure and properties depending on humidity with the using of various binders are presented in this article. This article dwells on the scientific study of opportunity physical-mechanical properties of composite materials optimization are considered. Objective.: Composite material contains hollow aluminum and silica microsphere. Method.: The study is based on the application of the method of separation of power and heat engineering functions. The method is based on the use of the factor structure optimality, which takes into account the primary and secondary stress fields of the structural gravel material. This indicates the possibility of obtaining gravel material with the most uniform distribution of nano - and microparticles in the gravel material and the formation of stable matrices with minimization of stress concentrations. Experiments show that the thickness of the cement shell, which performs power functions, is directly related to the size of the raw granules. At the same time, the thickness of the cement crust, regardless of the type of binder, with increasing moisture content has a higher rate of formation for granules of larger diameter. Results.: The conditions for the formation of gravel composite materials containing a hollow aluminosilicate microsphere are studied. The optimal structure and properties of the gravel composite material were obtained. The dependence of the strength function on humidity and the type of binder has been investigated. The optimal size and shape of binary form of gravel material containing a hollow aluminosilicate microsphere with a minimum thickness of a cement shell and a maximum strength function was obtained. Conclusion.: Received structure allows to separate power and heat engineering functions in material and to minimize the content of the excited environment centers.

Hierarchical ZSM-22/PHTS composite material and its hydro-isomerization performance in hydro-upgrading of gasoline

2021 ◽  
Author(s):  
Jiyuan Fan ◽  
Chengkun Xiao ◽  
Jinlin Mei ◽  
Cong Liu ◽  
Aijun Duan ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Impregnation Method ◽  
Molar Ratios

CoMo series catalysts based on ZSM-22/PHTS (ZP) composite materials with different SiO2/Al2O3 molar ratios were prepared via the impregnation method. The properties of the ZP material and the corresponding catalysts...

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