scholarly journals Diagrams of Deformation of Cement Composites Reinforced with Steel Wire Fiber

Author(s):  
Yuri V. Pukharenko ◽  
Dmitry A. Panteleev ◽  
Mikhail I. Zhavoronkov

Modern construction practice acquires such a tendency, at which it is required to use materials with increased physical, mechanical and operational characteristics, and at the same time, do not require significant material, labor and energy costs for their production. One of the most promising building materials that meet the requirements is fiber-reinforced concrete. However, the increase in the volume of its use is limited by the insufficient degree of study of its properties and characteristics. This problem is aggravated by the constantly expanding range of reinforcing fibers, which can give composites produced on their basis, completely different properties and characteristics. One of the most important characteristics of fiber-reinforced concrete is crack resistance. The most informative method of research of this characteristic is the construction and analysis of deformation and fracture diagrams of samples obtained during bending tensile strength tests. At the initial stage of the described study, several series of fiber-reinforced concrete samples were tested. During the tests, a standard method for assessing the fracture toughness of heavy and fine-grained concretes, governed by the requirements of GOST 29167, was used. A device specially designed for testing fiber-reinforced concrete was used. As a result of the tests, a general view of the deformation diagrams of fiber-reinforced concrete samples was established, strength and energy characteristics of crack resistance, as well as the modulus of elasticity were found, and the labor intensity of the tests was high. In this paper we describe a possible way of obtaining fracture patterns for fiber-reinforced concrete by calculation. The resulting diagrams of deformation of fiber-reinforced concrete samples are built on several key points, the determination of which coordinates is made by calculation. The paper compares the experimental and calculated fracture toughness characteristics of fiber-reinforced concrete manufactured using steel wire fiber. Comparison of the data presented indicates a satisfactory agreement between the calculated and experimental data, which proves the validity of the proposed method for obtaining fiber-reinforced concrete deformation diagrams.

2020 ◽  
Vol 6 (444) ◽  
pp. 47-56
Author(s):  
M.V. Doudkin ◽  
◽  
A.I. Kim ◽  
A.V. Vavilov ◽  
V.Yu. Chernavin ◽  
...  

The article presents the results of theoretical and, most importantly, experimental studies of some properties of steel-fiber-reinforcedconcrete reinforced with dispersed reinforcement from industrial wastes, namely, ITEX steel wire fiber from SPA INNOTECH from spent steel ropes, a large number of which are used as raw materials for fiber production, has accumulated in the region with the mining industry (East Kazakhstan region). The result of the research was indicators of tensile strength of fiber-reinforced concrete during bending of samples, characteristics of crack resistance, and impact strength indicators of fiber-reinforced concrete reinforced with fiber from industrial waste. Knowing and demonstrating these characteristics will make it possible to more effectively ensure the possibility of selling a new product on the building materials market. This publication has been carried out as part of the sub-project Technology for Manufacturing Fiber from Technogenic Wastes, funded by the Government of the Republic of Kazakhstan and the World Bank, Project for Stimulating Productive Innovations.


1985 ◽  
Vol 64 ◽  
Author(s):  
Surendra P. Shah

ABSTRACTDespite its extensive use, low tensile strength has been recognized as one of the major drawbacks of concrete. Although one has learned to avoid exposing concrete structures to adverse static tensile load, these cannot be shielded from short duration dynamic tensile stresses. Such loads originate from sources such as impact from missiles and projectiles, wind gusts, earthquakes and machine vibrations. The need to accurately predict the structural response and reserve capacity under such loading has led to an interest in the mechanical properties of the component materials at high rates of straining.One method to improve the resistance of concrete when subjected to impact and/or impulsive loading is by the incorporation of randomly distributed short fibers. Concrete (or Mortar) so reinforced is termed fiber reinforced concrete (FRC). Moderate increase in tensile strength and significant increases in energy absorption (toughness or impact-resistance) have been reported by several investigators in static tests on concrete reinforced with randomly distributed short steel fibers. A theoretical model to predict fracture toughness of FRC is proposed. This model is based on the concept of nonlinear elastic fracture mechanics.As yet no standard test methods are available to quantify the impact resistance of such composites, although several investigators have employed a variety of tests including drop weight, swinging pendulums and the detonation of explosives. These tests though useful in ascertaining the relative merits of different composites do not yield basic material characteristics which can be used for design.The author has recently developed an instrumented Charpy type of impact test to obtain basic information such as load-deflection relationship, fracture toughness, crack velocity and load-strain history during an impact event. From this information, a damage based constitutive model was proposed. Relative improvements in performance due to the addition of fibers as observed in the instrumented tests are also compared with other conventional methods.


2019 ◽  
Vol 46 (12) ◽  
pp. 1081-1089 ◽  
Author(s):  
Hossein Karimzadeh ◽  
Ali Razmi ◽  
Reza Imaninasab ◽  
Afshin Esminejad

This paper evaluated mixed mode I/II fracture toughness of fiber-reinforced concrete using cracked semi-circular bend (SCB) specimens subjected to three-point bending test. Additionally, a comparison was made between the experimental results and the estimations made by different theoretical criteria. Natural and synthetic fibers at various concentrations were used in this study. After producing cracks in SCB specimens at different inclination angles to induce different mixed mode loading conditions (from pure mode I to II), the fracture toughness of SCB specimens was determined. Furthermore, the compressive, splitting tensile, and flexural strength of natural and synthetic fiber-reinforced concrete were measured after 7 and 28 days of curing. While there is an increase in the aforementioned strengths with fiber content increase, 0.3% was found to be the optimum percentage regarding fracture toughness for both fibers. Also, the comparison between the experimental and theoretical results showed that generalized maximum tangential stress criterion estimated the experimental data satisfactorily.


2010 ◽  
Vol 168-170 ◽  
pp. 1784-1787
Author(s):  
Xiao Wei Wang ◽  
Wen Ling Tian ◽  
Ling Ling Fan ◽  
Ming Jie Zhou ◽  
Xiao Yan Zhao

In order to study the fracture toughness of steel fiber reinforced concrete (SFRC) and the postcracking toughness evaluation method, the fracture toughness tests were done for the four types of steel fibers and three kinds of matrix strength. According to the experiment curves of the load and the crack mouth opening displacement (Load-CMOD), the fracture toughness of SFRC was studied; the formulas of the postcracking toughness coefficient and the Fracture-CMOD toughness index were established. The experiment results show that the Fracture-CMOD toughness index can reflect sensitively to the effect on concrete toughness of the type of the steel fiber, and then it is avoid that the estimation error of the initial cracking point led to the evaluation error of the toughness.Comparison with other fibers B fiber shows the best crack resistance and the toughening ability.


2018 ◽  
Vol 212 ◽  
pp. 01007 ◽  
Author(s):  
Inna Korneyeva

The paper presents results of the statistical generalization of experimental data on the strength and deformability of fiber-reinforced concrete with different levels of bulk dispersion reinforcement. The range of the optimal content of reinforcing elements is established according to the criteria for ensuring maximum crack resistance and strength of the matrix (concrete).


2021 ◽  
Vol 1043 ◽  
pp. 61-65
Author(s):  
Tolya Khezhev ◽  
Aslan Kardanov ◽  
Eldar Bolotokov ◽  
Azamat Dottuyev ◽  
Ibrahim Mashfezh

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.


Sign in / Sign up

Export Citation Format

Share Document