scholarly journals Improvement of Strength and Strain Characteristics of Lightweight Fiber Concrete by Electromagnetic Activation in a Vortex Layer Apparatus

2021 ◽  
Vol 12 (1) ◽  
pp. 104
Author(s):  
Evgenii M. Shcherban’ ◽  
Sergey A. Stel’makh ◽  
Alexey Beskopylny ◽  
Levon R. Mailyan ◽  
Besarion Meskhi ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Processing Time ◽  
Structural Characteristics ◽  
Concrete Strength ◽  
Fiber Reinforced Concrete ◽  
Concrete Mixture ◽  
Deformation Characteristics ◽  
Fiber Reinforced ◽  
Construction Costs ◽  
Vortex Layer

The relevant problem of choosing effective materials for enclosing structures is compliance with the requirements of increased thermal resistance, reduced mass of buildings and structures, and reduced material consumption, labor intensity, and construction costs. These requirements are satisfied by structures made of lightweight fiber-reinforced concrete, which are the subject of attention of many scientists and engineers. One of the most rational requirements for industrial use is the activation of untreated components of the concrete mixture. This article is devoted to studying the influence of the activation of fiber-reinforced concrete elements in the vortex layer apparatus on concrete strength and structural characteristics. The effect of the raw component processing time of the concrete mixture on the strength and deformation characteristics of the lightweight fiber-reinforced concrete was studied. The optimal processing time for the cement–sand mortar in the VLA-75-85s was determined. It was shown that the activation of the vortex layer in the apparatus leads to an increase in strength from 27% to 61% and an improvement in the deformation characteristics of lightweight fiber-reinforced concrete by up to 12%. Furthermore, it was found that the use of activation in VLA leads to an increase in the coefficient of constructive quality for all experimentally determined strength characteristics of lightweight fiber-reinforced concrete by up to 27%.

DURABILITY PERFORMANCE AND DIMENSIONAL STABILITY OF POLYPROPYLENE FIBER REINFORCED CONCRETE

2018 ◽  
Vol 13 (2) ◽  
pp. 20-41 ◽  
Author(s):  
Ali Mardani-Aghabaglou ◽  
Süleyman Özen ◽  
Muhammet Gökhan Altun
Keyword(s):  
Reinforced Concrete ◽  
Dimensional Stability ◽  
Polypropylene Fiber ◽  
Pulse Velocity ◽  
Fiber Reinforced Concrete ◽  
Concrete Mixture ◽  
Fiber Reinforced ◽  
Concrete Mixtures ◽  
Durability Performance ◽  
Polypropylene Fiber Reinforced Concrete

In this study, the durability performance and dimensional stability of polypropylene fiber reinforced concrete mixture were investigated. For this purpose, two series of concrete mixtures, including a 0.45 water/cement ratio was prepared both in the absence and presence of fiber. A CEMI 42.5 R type portland cement and crushed limestone aggregate with a maximum particle size of 25 mm were used. In addition to the control mixture without fiber, three different concrete mixtures were prepared by adding polypropylene fiber as 0.4%, 0.8% and 1% of total volume into the mixture. The time-dependent fresh state properties, strength, ultrasonic pulse velocity, transport properties, drying shrinkage and freeze-thaw resistance of concrete mixtures, sodium sulfate attack and abrasion were investigated comparatively. Test results demonstrated that utilization of fiber affected the fresh properties of the concrete mixtures negatively. However, the 0.8% fiber-bearing mixture showed the highest performance in terms of durability and dimensional stability. Beyond this utilization ratio, the durability performance of the concrete mixture was negatively affected. The risk of nonhomogeneous dispersion of the fiber in the mixture was relatively high in the excess fiber-bearing mixture. Consequently, with the formation of flocculation in the mixture the void ratio of concrete mixture increased.

Diagram of Non-Linear Straining of Carbon-Fiber Reinforced Concrete at Static Effect

2016 ◽  
Vol 871 ◽  
pp. 173-181 ◽  
Author(s):  
Vasiliy Plevkov ◽  
Vyacheslav Belov ◽  
Igor Baldin ◽  
Andrey Nevskiy ◽  
Anatoliy Veselov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Strength ◽  
Experimental Studies ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Non Linear ◽  
Static Effect ◽  
Carbon Fiber Reinforced

The article reflects the results of experimental studies of carbon-fiber reinforced concrete under compression and tension. Qualitative change of concrete strength and stress-strain properties at its dispersed reinforcement with carbon fibers is fixed. As a result of the statistic processing of experimental data, analytical dependencies for determination of carbon-fiber reinforced concrete main strength and stress-strain characteristics under compression and tension are suggested. Calculation diagram of non-linear straining of carbon-fiber reinforced concrete at static effect is presented.

Fine-Grained Fibre Concrete of Run-Of-Crusher Stone Using Volcanic Ash

2021 ◽  
Vol 1043 ◽  
pp. 61-65
Author(s):  
Tolya Khezhev ◽  
Aslan Kardanov ◽  
Eldar Bolotokov ◽  
Azamat Dottuyev ◽  
Ibrahim Mashfezh
Keyword(s):  
Reinforced Concrete ◽  
Raw Materials ◽  
Concrete Strength ◽  
Basalt Fiber ◽  
Strength Properties ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fine Grained ◽  
Concrete Mixtures ◽  
Polyfunctional Additive

The results of the studies on the creation of self-compacting fine-grained fiber-reinforced concrete based on run-of-crusher stone with the use of a polyfunctional additive D-5 are presented. Compositions of self-compacting fine-grained fiber-reinforced concrete with the use of basalt fiber have been developed, which significantly reduce cement consumption and improve the characteristics of fine-grained concrete mixture and concrete. Using a polyfunctional additive D-5in mixtures makes it possible to increase the strength properties of fine-grained fiber-reinforced concrete while improving the concrete mixtures’ rheological characteristics. Replacement of cement up to 10% of the mass by ash fraction d<0.14 min fine-grained concrete mixtures does not cause a noticeable decrease in the concrete strength properties. The developed self-compacting fine-grained fiber-reinforced concretes have increased strength properties and have a low-cost price due to the use of local raw materials and run-of-crusher stone.

scholarly journals Optimization of Composition and Technological Factors for the Lightweight Fiber-Reinforced Concrete Production on a Combined Aggregate with an Increased Coefficient of Structural Quality

2021 ◽  
Vol 11 (16) ◽  
pp. 7284
Author(s):  
Levon R. Mailyan ◽  
Alexey N. Beskopylny ◽  
Besarion Meskhi ◽  
Sergey A. Stel’makh ◽  
Evgenii M. Shcherban ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Structural Quality ◽  
Deformation Characteristics ◽  
Fiber Reinforced ◽  
Distribution Method ◽  
Concrete Production ◽  
Strength And Deformation ◽  
Control Composition

In recent years, developing lightweight concrete with both the necessary and sufficient strength characteristics is essential in the construction industry. This article studies the influence of the volumetric composition of lightweight fiber-reinforced concrete (LFRC) and the method of its distribution during the preparation of the fiber–concrete mixture on the strength and deformation characteristics of LFRC on a combined aggregate. The optimal grain size of the porous filler was calculated by the mathematical planning method of the experiment. Regression models of the strength and deformation characteristics on the volumetric content of fiber and its distribution method were obtained. The most effective combination of these factors has been determined. The model shows that the increase in compressive strength was 12%, the value of the prismatic strength increased by 25%, the bending tensile strength increased by 34%, and the axial tensile strength increased by 11%. The ultimate strains during axial compression decreased by 10%, axial tension decreased by 12%, and the elasticity modulus increased by 11% compared to the test results of the control composition samples without fiber and pumice. The coefficient of constructive quality (CCQ) of the LFRC on a combined aggregate compared to concrete with the control composition without fiber and pumice showed an increase of more than 32%. It was also found that fiber reinforcement with basalt fibers with a combination of heavy and porous aggregates achieves a synergistic effect together.

scholarly journals Application of fibro concrete mixture at construction of bases and coatings automobile roads

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Tatiana Levkovich ◽  
Zelgedin Mevlidinov ◽  
Nikita Fedin
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Fiber Reinforced Concrete ◽  
Concrete Mixture ◽  
Crushed Stone ◽  
Fiber Reinforced ◽  
Cement Concrete ◽  
Shock Loads ◽  
Tensile Stresses ◽  
Fiber Concrete

Fiber concrete – concrete with the inclusion of fibers (fibers) from inorganic or organic materials (steel, glass, polyethylene, etc.). Fiber concrete reinforced with fibers, has a high resistance to shock loads and abrasion, well perceives tensile stresses. An important issue in the preparation of fiber-reinforced concrete is its mobility. One of the difficulties encountered in practice when working with fiber reinforced concrete, reinforced by steel wire, is its lack of workability. To ensure the required workability of the concrete mixture and to achieve a uniform distribution of wire segments in it, it is necessary, in addition to the wire segments and the core, to control their ratio. Tests of fiber reinforced concrete showed that the larger the aggregate size, the lower the flexural strength. The use of granite crushed stone with a size of 20 mm allows to obtain better results than when using crushed stone from gravel or limestone. While in ordinary concrete, the quality of rubble increases the flexural strength, in fibrous concrete, the flexural strength increases the effectiveness of the fibers. The use of fiber-reinforced concrete in the construction of road pavements is determined by technical and economic efficiency, which is caused by the most complete use of the positive properties of fiber-reinforced concrete as compared to conventional cement concrete. Fiber concrete has several advantages compared to conventional cement concrete: a) increased crack resistance, impact toughness, wear, – frost and fire resistance, thermodynamic resistance, etc.; b) the possibility of use without conventional rod or wire steel reinforcement; c) reducing labor costs for reinforcement works, increasing the degree of mechanization and automation of road and airfield pavement construction. In recent years, the use of concrete (cement concrete) foundations and pavements of highways and industrial sites has begun to revive in road construction. The use of various types of cement concrete and fiber concrete (steel fiber concrete, glass fiber concrete, fiber concrete on synthetic fiber) will increase the durability of road and airfield pavements, increasing resistance to shock loads, abrasion and tensile stresses.

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