scholarly journals Testing an Impedance Non-destructive Method to Evaluate Steel-Fiber Concrete Samples

2018 ◽  
Vol 18 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Tereza Komarkova ◽  
Pavel Fiala ◽  
Miloslav Steinbauer ◽  
Zdenek Roubal
Keyword(s):  
Composite Material ◽  
Steel Fiber ◽  
Fiber Composite ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Measuring Device ◽  
Steel Fiber Concrete ◽  
Measured Sample ◽  
Non Destructive ◽  
Sample Set

Abstract Steel-fiber reinforced concrete is a composite material characterized by outstanding tensile properties and resistance to the development of cracks. The concrete, however, exhibits such characteristics only on the condition that the steel fibers in the final, hardened composite have been distributed evenly. The current methods to evaluate the distribution and concentration of a fiber composite are either destructive or exhibit a limited capability of evaluating the concentration and orientation of the fibers. In this context, the paper discusses tests related to the evaluation of the density and orientation of fibers in a composite material. Compared to the approaches used to date, the proposed technique is based on the evaluation of the electrical impedance Z in the band close to the resonance of the sensor–sample configuration. Using analytically expressed equations, we can evaluate the monitored part of the composite and its density at various depths of the tested sample. The method employs test blocks of composites, utilizing the resonance of the measuring device and the measured sample set; the desired state occurs within the interval of between f=3 kHz and 400 kHz.

scholarly journals A Non-Destructive Impedance Method Using Resonance to Evaluate the Concentration of Steel Fibers in Concrete

2018 ◽  
Vol 18 (5) ◽  
pp. 218-226 ◽  
Author(s):  
T. Bachorec ◽  
P. Fiala ◽  
M. Steinbauer ◽  
Z. Roubal
Keyword(s):  
Composite Material ◽  
Fiber Composite ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Impedance Method ◽  
Steel Fiber Reinforced Concrete ◽  
Destructive Testing ◽  
Measuring Device ◽  
Measured Sample ◽  
Non Destructive

Abstract Steel-fiber reinforced concrete is a composite material characterized by outstanding tensile properties and resistance to cracking. The concrete, however, exhibits such characteristics only on the condition that the steel fibers in the final, hardened composite are distributed evenly. Current methods to evaluate the distribution and concentration in a fiber composite are either destructive or exhibit a limited capability of evaluating the concentration and orientation of the fibers. In this context, the paper discusses auxiliary techniques and laboratory tests that evaluate the density and orientation of the fibers in a composite material, presenting an innovative approach to impedance-based non-destructive testing. The actual methodology utilizes the resonance of the measuring device and the measured sample set; the desired state occurs within the interval of f = 10 kHz and 2 GHz.

scholarly journals The change in impermeability of steel fiber reinforced concrete with high strength cement-sand matrix at heating

2020 ◽  
Vol 17 (1) ◽  
pp. 150-155
Author(s):  
V. A. Dorf ◽  
◽  
R. O. Krasnovskij ◽  
D. E. Kapustin ◽  
P. S. Sultygova ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Heating Temperature ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Concrete ◽  
The Matrix ◽  
Steel Fiber Concrete

The paper considers the effects of high temperatures in case of fire on the change in impermeability of steel fiber reinforced concrete having a high-strength cement-sand matrix and various content of fiber of different types, sizes, and strength. It is shown that in the temperature range from 20° to 1100° C in the diagram “Heating temperature - impermeability class», the matrix and steel fiber concrete(SFC) have a S-shaped character, and in case of heating temperature of over 100 °C, there comes a distinct decrease in impermeability.

Techniques of Non-Destructive Testing of Steel Fiber Reinforced Concrete

2017 ◽  
Vol 755 ◽  
pp. 153-158 ◽  
Author(s):  
Eva Zezulová ◽  
Tereza Komárková
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Non Destructive Testing ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Destructive Testing ◽  
Measurement Devices ◽  
Non Destructive

Non-destructive testing (NDT) is seeing increasingly frequent use in civil engineering thanks to the fact that the tests are repeatable and do not cause serious damage to the material. The requirements for the development and modernization of available testing devices and methodologies are ever increasing and the testing of existing structures often requires the use of NDT. Unfortunately, every measurement and methodology has its limits and the measurement devices for the evaluation of steel fiber reinforced concrete (SFRC) are no exception. In recent decades there has been an effort to modernize and develop existing measurement devices for SFRC testing. This building material is commonly used especially in large-scale structures. Nevertheless, the technology of SFRC could seem complicated when compared with ordinary concrete and the very nature of this composite material could lead to SFRC inhomogeneity during construction. This paper describes the assessment of SFRC by more or less available methodologies and measurements utilizing non-destructive principles.

The Design Application of Steel Fiber Concrete on Bottom Frame Structure

2013 ◽  
Vol 639-640 ◽  
pp. 1241-1244
Author(s):  
Jun Zuo
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Internal Force ◽  
Fiber Reinforced Concrete ◽  
Frame Structure ◽  
Steel Fiber Reinforced Concrete ◽  
Concrete Frame ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Bottom Frame

The concrete frame with bottom frame structure bear the load from the upper floors, roofing and brick walls, internal force is quite large, so the designed section size of frame beams is big, sometimes even the clear height of the building can't meet the architectural requirements; And more reinforcement, construction of concrete are difficult to pound, even vibration bar are difficult to insert into the beam, seriously influence the construction quality of reinforced concrete and the frame structure quality can't t be assured. This article introduces the design and application of steel fiber reinforced concrete in the bottom frame through the practical engineering examples. Steel fiber concrete can enhance the tensile and shear strength, and make it has good resistance to crack and toughness. As a result of the steel fiber concrete, the bearing capacity of bottom frame is greatly improved, and the problem in the project is solved.

scholarly journals LABORATORY TESTING OF STEEL FIBER CONCRETE PRISM FOR TENSION IN BENDING

2020 ◽  
pp. 105-113
Author(s):  
M.G. Surianinov ◽  
◽  
S.P. Neutov ◽  
I.B. Korneeva ◽  
I.K. Kalchev ◽  
...  
Keyword(s):  
Crack Resistance ◽  
Bearing Capacity ◽  
Steel Fiber ◽  
Fiber Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Fiber Concrete ◽  
Steel Fiber Concrete

Abstract. Laboratory bending tests of concrete and steel-fiber-concrete prisms were carried out. The concrete matrix for all prisms is made of a concrete mixture of the same composition with a coarse aggregate size up to 10 mm and a water-cement ratio that allows correct mixing of the ready mixture with fiber, so that the latter is evenly distributed over the sample volume. Fiber reinforcement is 1% for all three types of fiber, a fiber made of the same steel with an ultimate strength of 1335 MPa, fiber length 50 mm, diameter 1 mm is used. Fibers differ only in shape, which makes it possible to compare test results across series without correction factors. Concrete samples without fiber are considered as control samples. As a result of laboratory tests, data sets were obtained and analyzed, which are presented in the form of diagrams. Different types of steel fiber show different increases in the load at the beginning of cracking and load-bearing capacity. The most profitable from this point of view is the addition of anchor fiber to concrete, the least – wave fiber. However, the presence of any of the considered steel fibers in the mixture significantly increases the load-bearing capacity of the sample. In addition, the type of destruction of such a sample changes from brittle to viscous. We also studied the deformability of samples with different fiber reinforcement and plotted the dependence of the relative longitudinal strain on the load. Before the crack formation begins, there is a direct proportionality between the load and the strain with the appearance of cracks, the slope of the graphs changes sharply. When the load-bearing capacity is lost, steel fiber-reinforced concrete samples are restrained from final destruction. The use of steel fiber in concrete on average increases the crack resistance by 40%, and the load-bearing capacity by 64%. Compared with samples without fiber reinforcement, samples with anchor fiber show an increase in load-bearing capacity by 89%, and crack resistance by 61%. When using flattened fiber, these values are 56% and 32%, and for wave fiber – 47% and 25%, respectively. The use of steel fiber in the manufacture of concrete mix avoids the brittle nature of destruction.

scholarly journals Research status and prospect of waste steel fiber reinforced concrete

2021 ◽  
Vol 248 ◽  
pp. 03039
Author(s):  
Yu Binglin
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Scrap Tire ◽  
Research Status ◽  
Fiber Concrete ◽  
Steel Fiber Concrete

Scrap steel fiber concrete (SFRC) is a new kind of concrete material, which uses the scrap steel fiber from the scrap tire as the reinforced fiber of FRP bar fiber reinforced concrete, replacing or partially replacing the traditional steel fiber and synthetic fiber. This paper summarizes the research status of waste steel fiber at home and abroad, including the mechanical properties of compressive and tensile resistance, the mixing amount and use requirements of waste steel fiber, and finally the development prospect of waste steel fiber concrete is forecasted

scholarly journals Mechanical Properties of Steel Fiber-Reinforced Concrete by Vibratory Mixing Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yuanxun Zheng ◽  
Xiaolong Wu ◽  
Guangxian He ◽  
Qingfang Shang ◽  
Jianguo Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Steel Fiber Concrete ◽  
Mixing Method ◽  
Splitting Tensile Test

As a kind of important engineering material, steel fiber-reinforced concrete was used widely in civil engineering. Up to now, steel fiber-reinforced concrete was usually produced by the traditional mixing method. For the reason of uniform distribution of fiber, the reinforcement of mechanical properties of concrete was inadequately performed. In this paper, C50 steel fiber-reinforced concrete and C60 steel fiber-reinforced concrete were manufactured by traditional mixing and vibratory mixing methods, respectively, and then, the cube compression test, flexural test, splitting tensile test, and the bending test were carried out. The reinforcement effects of mechanical properties were analyzed by comparing the traditional mixing and vibratory mixing methods. The results show that vibratory mixing can effectively improve the distribution of steel fibers in concrete and can increase the density of steel fiber concrete, and therefore, it effectively improves the mechanical properties of steel fiber-reinforced concrete when compared to the traditional mixing method.

Study and Comparison of Characteristics of Models of Hollow-Core Slabs, Reinforced Concrete and Steel-Fiber Concrete

2020 ◽  
Vol 864 ◽  
pp. 9-18
Author(s):  
Mykola Surianinov ◽  
Stepan Neutov ◽  
Iryna Korneieva ◽  
Maryna Sydorchuk
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Fiber Reinforced Concrete ◽  
Hollow Core ◽  
Steel Fiber Reinforced Concrete ◽  
Reinforced Concrete Slab ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Correct Data

Two models of hollow core slabs were tested: reinforced concrete and steel fiber concrete. When designing slab models, the proportions of full-sized structures were preserved for the further possibility of correct data comparison. As a result of testing models of hollow core slabs, it was found that the bearing capacity of a slab with combined reinforcement is 24% higher than that of reinforced concrete, the deflection is 36% less, and the crack resistance is 18% higher. The use of steel fiber made it possible to avoid the brittle fracture of a steel fiber reinforced concrete slab, which was observed in the model of a conventional reinforced concrete slab.

scholarly journals Steel fiber concrete. Constructions. Terminology

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Klara Talantova
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Steel Fiber ◽  
Concrete Structures ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Structures ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Steel Fiber Concrete ◽  
Composite Steel

The article discusses the terms and definitions that are increasingly appearing in the open press and on the Internet, confusing well-established concepts. The purpose of considering terminology issues is an attempt to draw the attention of the community of builders – scientists and practitioners to the inadmissibility of inaccuracy and incorrect choice of terms and definitions in the technical, scientific and even regulatory literature. The article discusses the transformation (changes) of terminology in the field of dense concretes, reinforced concrete structures, as well as structures based on a building composite – steel fiber reinforced concrete. In particular, concrete is a composite, reinforced concrete is not a collective name for reinforced concrete structures and products, but material, moreover, is composite. At the same time, steel fiber concrete is a hardened concrete. This approach is an important reason for restraining widespread use in the practice of building structures based on steel fiber reinforced concrete. These terms are often used in the open press, depriving the discussed topics of physical meaning, and, as a result, the impossibility of obtaining the expected result. At the same time, the open press provides information on composite materials, the peculiarities of creating and managing their properties. The article presents the established generally accepted terms and definitions that correspond to the physical nature of concrete, reinforced concrete structures, composite materials and structures based on composite – steel fiber reinforced concrete. The definition of composite materials, the principles of their creation, as well as the features of the composite – steel fiber reinforced concrete and methods of forming its structure are presented. A method is shown for obtaining the properties of steel fiber reinforced concrete in accordance with the stress-strain state of the developed structural element and creating structures based on it with properties specified in accordance with the conditions of their operation and having technical and economic indicators that exceed those of standard structures – analogues.

scholarly journals The Effect of Vibration Mixing on the Mechanical Properties of Steel Fiber Concrete with Different Mix Ratios

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3669
Author(s):  
Chunyu Zhang ◽  
Yikai Sun ◽  
Jianguo Xu ◽  
Bo Wang
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Ratio ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Fiber Concrete ◽  
Steel Fiber Concrete

This work addresses how vibration stirring, steel-fiber volume ratio, and matrix strength affect the mechanical properties of steel-fiber-reinforced concrete. The goal of the work is to improve the homogeneity of steel-fiber-reinforced concrete, which is done by comparing the mechanical properties of steel-fiber-reinforced concrete fabricated by ordinary stirring with that fabricated by vibration stirring. The results show that the mechanical properties of steel-fiber-reinforced concrete produced by vibration mixing are better than those produced by ordinary mixing. The general trend is that the mechanical properties of steel-fiber concrete have a linear relationship with the matrix strength and the volume ratio of steel fiber. The best mechanical properties are obtained for a steel-fiber volume ratio of less than 1%. We have also established calculation models for the mechanical performance index of vibration, mixing steel-fiber concrete based on the test results. Microscopic studies show that vibration stirring optimizes the microstructure of the transition zone between the concrete interface and the slurry, and improves the homogeneity of the steel-fiber-reinforced concrete, and enhances the adhesion between the mixture components.

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