scholarly journals Mechanical Properties of Concrete Slabs Reinforced with Recycled Steel Fibers from Post-Consumer Tires in Bogotá, Colombia

2020 ◽  
Vol 30 (2) ◽  
pp. 67-79
Author(s):  
Julián Carrillo ◽  
Carlos Díaz
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Concrete Slabs ◽  
Compression Tests ◽  
Steel Fiber Reinforced Concrete ◽  
Alternative Reinforcement ◽  
Recycled Fibers ◽  
Recycled Steel

Millions of post-consumer tires are not adequately disposed of each year, and thus, are producing an enormous environmental problem in the world. This environmental impact may be reduced when assessing this material as an alternative reinforcement for concrete. It is widely known that the toughness of steel fiber-reinforced concrete is suitably assessed by energy absorption tests on slabs. The purpose of this paper is to show and discuss the results of a research aimed at assessing the mechanical response of concrete slabs reinforced with recycled steel fibers from post-consumer tires in Bogotá, Colombia. The testing program of the study comprised 31 axial compression tests on cylinders, and 15 bending tests on concrete slabs reinforced with nominal dosages of 15, 30, and 60 kg/m3 of industrial steel fibers or recycled fibers obtained from post-consumer tires. Based on the measured response, preliminary design equations are proposed to estimate the mechanical properties of concrete reinforced with recycled steel fibers.

Study on Retrofitting and Strengthening of Reinforced Concrete Beams Using Fibrous Concrete

2021 ◽  
Vol 9 (8) ◽  
pp. 1676-1684
Author(s):  
Natalia Sharma
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Cement Matrix ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

Abstract: Reinforced concrete structures are frequently in need of repair and strengthening as a result of numerous environmental causes, ageing, or material damage under intense stress conditions, as well as mistakes made during the construction process. RC structures are repaired using a variety of approaches nowadays. The usage of FRC is one of the retrofitting strategies. Steel fiber reinforced concrete (SFRC) was used in this investigation because it contains randomly dispersed short discrete steel fibers that operate as internal reinforcement to improve the cementitious composite's characteristics (concrete). The main rationale for integrating small discrete fibers into a cement matrix is to reduce the amount of cement used. The principal reason for incorporating short discrete fibers into a cement matrix is to reduce cracking in the elastic range, increase the tensile strength and deformation capacity and increase the toughness of the resultant composite. These properties of SFRC primarily depend upon length and volume of Steel fibers used in the concrete mixture. In India, the steel fiber reinforced concrete (SFRC) has seen limited applications in several structures due to the lack of awareness, design guidelines and construction specifications. Therefore, there is a need to develop information on the role of steel fibers in the concrete mixture. The experimental work reported in this study includes the mechanical properties of concrete at different volume fractions of steel fibers. These mechanical properties include compressive strength, split tensile strength and flexural strength and to study the effect of volume fraction and aspect ratio of steel fibers on these mechanical properties. However, main aim of the study was significance of reinforced concrete beams strengthened with fiber reinforced concrete layer and to investigate how these beams deflect under strain. The objective of the investigation was finding that applying FRC to strengthen beams enhanced structural performance in terms of ultimate load carrying capacity, fracture pattern deflection, and mode of failure or not.

scholarly journals Shrinkage and Mechanical Properties of Self-Compacting SFRC With Calcium-Sulfoaluminate Expansive Agent

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 588 ◽  
Author(s):  
Changyong Li ◽  
Pengran Shang ◽  
Fenglan Li ◽  
Meng Feng ◽  
Shunbo Zhao
Keyword(s):  
Mechanical Properties ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Cementitious Materials ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Steel Fiber Reinforced Concrete ◽  
Volume Stability ◽  
Calcium Sulfoaluminate ◽  
Expansive Agent

With the premise of ensuring workability on a fresh mixture, the volume stability of hardened self-compacting steel fiber reinforced concrete (SFRC) becomes an issue due to the content of cementitious materials increased with the volume fraction of steel fiber. By using the expansive agent to reduce the shrinkage deformation of self-compacting SFRC, the strength reduction of hardened self-compacting SFRC is another issue. To solve these issues, this paper performed an experimental investigation on the workability, shrinkage, and mechanical properties of self-compacting SFRC compared to the self-compacting concrete (SCC) with or without an expansive agent. The calcium-sulfoaluminate expansive agent with content optimized to be 10% mass of binders and the steel fiber with a varying volume fraction from 0.4% to 1.2% were selected as the main parameters. The mix proportion of self-compacting SFRC with expansive agent was designed by the direct absolute volume method, of which the steel fibers are considered to be the distributed coarse aggregates. Results showed that rational high filling and passing ability of fresh self-compacting SFRC was ensured by increasing the binder to coarse-aggregate ratio and the sand ratio in the mix proportions; the autogenous and drying shrinkages of hardened self-compacting SFRC reduced by 22.2% to 3.2% and by 18.5% to 7.3% compared to those of the SCC without expansive agent at a curing age of 180 d, although the expansion effect of expansive agent decreased with the increasing volume fraction of steel fiber; the mechanical properties, including the compressive strength, the splitting tensile strength, and the modulus of elasticity increased with the incorporation of an expansive agent and steel fibers, which met the design requirements.

scholarly journals Mechanical Properties and Explosive Spalling Behavior of Steel-Fiber-Reinforced Concrete Exposed to High Temperature—A Review

2020 ◽  
Vol 10 (7) ◽  
pp. 2324 ◽  
Author(s):  
Peng Zhang ◽  
Luoyi Kang ◽  
Juan Wang ◽  
Jinjun Guo ◽  
Shaowei Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Elevated Temperatures ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Explosive Spalling ◽  
Residual Properties

Steel-fiber-reinforced concrete (SFRC) is being increasingly applied to various buildings and civil infrastructure as an advanced cementitious composite. In recent years, the requirements for SFRC in the construction industry have increased. Additionally, the fire resistance of SFRC has attracted attention; therefore, numerous investigations regarding the residual properties of SFRC have been conducted. This paper critically reviews the mechanical properties of SFRC subjected to elevated temperatures, including its residual compressive strength, flexural strength, tensile strength, elastic properties, fracture properties, and stress–strain relationships. The residual mechanical performance of SFRC and the action mechanism of steel fibers are reviewed in detail. Moreover, factors affecting the explosive spalling of concrete at high temperatures as well as the effect of steel fibers on the microstructure of heated concrete are discussed. It is demonstrated that, in general, SFRC exhibits better residual mechanical properties when exposed to elevated temperatures than plain concrete and can prevent the risk of explosive spalling more effectively. The purpose of this literature review is to provide an exhaustive insight into the feasibility of SFRC as a refractory building material; additionally, future research needs are identified.

Influence of Dispersed Reinforcement on the Physico-Mechanical Properties of the SFRC

2017 ◽  
Vol 755 ◽  
pp. 75-81 ◽  
Author(s):  
Tereza Komárková ◽  
Jaromír Láník ◽  
Petr Dvořák
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Steel Fiber ◽  
Fresh Concrete ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Mechanical Parameters ◽  
Steel Fiber Reinforced Concrete ◽  
The Individual ◽  
Building Practice

The article deals with steel fiber reinforced concrete (SFRC), specifically with its physical mechanical parameters which influence both design and reliable behavior of the building material in structures. The resulting physical mechanical properties of the SFRC depend on the properties of the individual components and also on their quantity. In the building practice, a common dosing of steel fibers that are added into fresh concrete mixture is ranging between 0.5% and 2%. The paper also describes the methodology of certain laboratory tests suitable for SFRC and the ways of data evaluation. The experiments proved a substantial influence of the quantity of steel fibers in the individual mixtures to the resulting mechanical properties.

scholarly journals Influence of Tire-Recycled Steel Fibers on Strength and Flexural Behavior of Reinforced Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yancong Zhang ◽  
Lingling Gao
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Plastic Material ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Flexural Behavior ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Flexural Toughness ◽  
Recycled Steel

Tire production is increasing every year due to the increase in vehicle sales. The generation and disposal of waste are inherent to life itself and have presented very serious problems to the human community in China. Recently, some research has been devoted to the use of tire-recycled steel fibers in concrete. This study is focusing on the use of tire-recycled steel fibers. Several volume ratios of tire-recycled steel fibers were used in concrete mix to fabricate and test. Reinforced concrete obtains evidence and satisfactory improvement by adding tire-recycled steel fibers, mostly in compressive strength, splitting strength, flexural tensile strength, and flexural toughness. The strength and flexural toughness of the tire-recycled steel fiber reinforced concrete are lower than those of industrial steel fibers. To obtain concrete with approximately the same strength or toughness, the content of tire-recycled steel fibers should be about 1%-2% higher than that of industrial steel fibers. In addition, the load-deflection curve tends to become fuller after the first crack, and the second peak of the load continues to increase. The steel fiber reinforced concrete is getting closer to the ideal elastic-plastic material.

scholarly journals Effect of High Temperature on the Mechanical Properties of Steel Fiber-Reinforced Concrete

Fibers ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 100 ◽  
Author(s):  
Augusto C. S. Bezerra ◽  
Priscila S. Maciel ◽  
Elaine C. S. Corrêa ◽  
Paulo R. R. Soares Junior ◽  
Maria T. P. Aguilar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
High Temperature ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
High Temperature Treatment ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Aspect Ratios

The effect of high temperature on the mechanical properties of concrete reinforced by steel fibers with various aspect ratios has been investigated in this study. Concrete specimens were fabricated from four different concrete mixtures and cured for 28 days. After curing and natural drying, the specimens were annealed at a temperature of 500 °C for 3 h in an electric furnace. The compressive and tensile strengths as well as the elastic moduli of the produced specimens were determined. It was found that the mechanical properties (especially flexural toughness) of steel fiber-reinforced concrete were less affected by high temperature as compared to those of control concrete specimens. The flexural tensile strength of fiber-reinforced concrete measured after high-temperature treatment was almost equal to the value obtained for the reference concrete specimen at room temperature. It should be noted that the addition of steel fibers to concrete preserves its mechanical properties after exposure to a temperature of 500 °C due to fire for a period of up to 3 h, and thus is able to improve its high-temperature structural stability. The test results of this study indicate that the use of steel fibers in concrete-based materials significantly enhances their fire and hear-resistant characteristics.

Silica Fume Effects on the Pull-Out Behavior of Randomly Oriented Steel Fibers from Concrete

1987 ◽  
Vol 114 ◽  
Author(s):  
Parviz Soroushian ◽  
Ziadz Bayasi
Keyword(s):  
Silica Fume ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Steel Fiber Reinforced Concrete ◽  
Pull Out ◽  
Fiber Concrete ◽  
Pull Out Strength

ABSTRACTSilica fume is known to improve the pore system of cementitious pastes and their adhesion capacity to fibers and other mix inclusions. This study has been mainly concerned with the effect of silica fume on the pull-out strength of randomly oriented steel fibers from concrete. Silica fume effects on the fresh mix workability and the overall flexural and compressive behavior of steel fiber reinforced and plain concretes were also assessed. The only variable in different fibrous and plain mixes was the fraction of portland cement substituted with silica fume. This fraction ranged from 0% to 20%.The workability of plain and fibrous mixes were obtained by slump and inverted slump cone tests, respectively. In both the flexure and compression tests on fiber concrete, the complete load-deformation relationship was obtained. The pull-out strength of randomly oriented fibers was assessed through analysis of the flexural test data.All aspects of the fresh and hardened steel fiber reinforced concrete performance considered in this study, especially the pull-out strength of randomly oriented fibers from concrete, were observed to improve with the increase in silica fume-cementitious ratio up to a certain limit, after which the trends in silica fume effects were reversed.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

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