Study on Losses of Self-Stress Created by Steel Fiber Reinforced Self-Stressing Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 300-303 ◽  
Author(s):  
Bo Xin Wang ◽  
He Nan Jin ◽  
Teng Man
Keyword(s):  
Steel Fiber ◽  
Theoretical Models ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Bars ◽  
The Matrix ◽  
The Stability

Based on the 9-year-experiment of self-stressing concrete (SSC for short), the stability of self-stress caused by steel bars and steel fibers is investigated. The results show that the losses of self-stress are only from 0.6 MPa to 1.2 MPa during 2.5 years. Meanwhile the matrix of steel fiber reinforced self-stressing concrete (SFRSSC for short) has the characteristic of secondary expansion. Finally, according to the existing theoretical models, formulas of the losses of self-stress created by SFRSSC are obtained.

Study on Restrained Expansive Deformation of Steel Fiber Reinforced Self-Stressing Concrete

2008 ◽  
Vol 385-387 ◽  
pp. 305-308
Author(s):  
Huan An He ◽  
Cheng Kui Huang
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
The Troubles ◽  
Steel Bar ◽  
Steel Bars ◽  
Steel Fiber Concrete

A new sort of high performance concrete is introduced which combines most advantages of prestressed concrete and steel fiber concrete, named steel fiber reinforced self-stressing concrete(SFFRSSC for short). Self-stressing concrete is actually a kind of expansive concrete which self-stresses, namely pre-compressive stresses, are induced by dint of some restrictions generally provided by steel bars to concrete expansion after hydration of expansive cement. As a result of chemical reaction, concrete archived prestresses by itself different from mechanical prestressed concrete, so called self-stressing concrete. By distributing short-cut steel fibers into self-stressing concrete at random, prestresses( self-stress) are created in concrete under combined restriction of steel bars and steel fibers. Thank to the pre-stresses tensile strength of concrete are significantly increased as well as cracking strength. In addition, expansive deformation of SFFRSSC can compensate the shrinkage of concrete to decrease shrinkage crack, and the steel fibers play an important role in post-crack behavior. On the other hand, self-stressing concrete can avoid the troubles of construction compared with conventional mechanical prestressed concrete. For purpose of understanding the properties of SFFRSSC, in this paper some researches were carried out to investigate the special expansive behaviors of restrained expansive deformation with restriction of steel bar as well as steel fiber. The test results indicated that steel bar and steel fiber both provide effective restrict to self-stressing concrete as result of forming prestresses in concrete.

Performance on Steel Fiber Reinforced Self-Stressing Concrete

2008 ◽  
Vol 400-402 ◽  
pp. 427-432
Author(s):  
Huan An He ◽  
Bo Xin Wang ◽  
Jian Ting Lin
Keyword(s):  
Tensile Strength ◽  
Prestressed Concrete ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
The Troubles ◽  
Steel Bars ◽  
Steel Fiber Concrete

In this paper a new sort of high performance concrete is introduced which combines most advantages of prestressed concrete and steel fiber concrete, named steel fiber reinforced self-stressing concrete(SFFRSSC for short). Self-stressing concrete is actually a kind of expansive concrete which self-stresses, namely pre-compressive stresses, are induced by dint of some restrictions generally provided by steel bars to concrete expansion after hydration of expansive cement. As a result of chemical reaction, concrete archived prestresses by itself different from mechanical prestressed concrete, so called self-stressing concrete. By distributing short-cut steel fibers into self-stressing concrete at random, self-stresses are generated in concrete under combined restriction of steel bars as well as steel fibers. Thank to the pre-stresses tensile strength of concrete are significantly increased as well as cracking strength. In addition, on the one hand, expansive deformation of SFFRSSC can compensate the shrinkage of concrete to decrease non-loaded cracks resulting from shrinkage, and even when cracking, the steel fibers play an important role in resistance to crack development. On the other hand, self-stressing concrete can avoid the troubles of construction compared with conventional mechanical prestressed concrete. Therefore, above-mentioned advantages of SFFRSSC over ordinary concrete imply a better prospect in using SFFRSSC in civil engineering. For purpose of understanding the properties of SFFRSSC, in this paper some researches were carried out to investigate the special expansive behaviors with ages and tensile strength. The test results indicated that at early age the expansion of SFFRSSC developed rapidly but 14 day the 90% of overall expansive deformation basically fulfilled and subsequently expansion kept stable. Axial tensile test result showed that tensile strength were improved 2-3 times for self-stressing concrete specimens restrained by steel bars as well as steel fibers.

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.

scholarly journals Strength And Durability Properties Of Steel Fiber Reinforced Self Compacting Concrete

2021 ◽  
Vol 12 (5) ◽  
pp. 818-826
Author(s):  
Sumith Vangara, S Siva Rama Krishna, Venu Malagavelli, K.Tarunkumar, A. Jagadish Babu
Keyword(s):  
Steel Fiber ◽  
Design Procedure ◽  
Steel Fibers ◽  
Second Phase ◽  
Initial Surface ◽  
Fiber Reinforced ◽  
Acid Attack ◽  
Self Compacting Concrete ◽  
Surface Absorption ◽  
Durability Properties

In this present study the durability characteristics of Steel fiber reinforced Self compacting concrete (SFRSCC) is determined for M30 and M40 grade concrete mixes. Along with durability strength and sorptivity is carried out and comparison is made with Plane self-compacting concrete (SCC) by chemical resistances, Initial Surface Absorption Test (ISAT). In the present study, the rational mix design procedure for self-compacting concrete is used. SCC mixes contains large quantity of powder (material whose parcel size is 0.125 mm) to maintain the plastic yield of the properties of fresh concrete as per the general guidelines for design of SCC mixes given in the EFNARC (2005). The present project consists of two phases. In the first phase, SCC mixes for different grades are developed without steel fibers and with steel fibers. The mechanical properties like compressive strength of the different grades were studied. In the second phase, based on the experimental results, durability properties were studied with the using of specimens of size 100 mm × 100 mm × 100 mm. Durability studies like Acid attack factors, Acid-Durability factors, Sulphate attack factors, Sorptivity are studied for the Plain SCC and steel Fiber Reinforced SCC and a comparison is made.

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.

Punching Shear Capacity of Steel Fiber Reinforced Concrete Slab- Column Connections

2019 ◽  
Author(s):  
Josef Landler ◽  
Oliver Fischer
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Type ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Fiber Reinforced

<p>To design flat slabs directly supported on columns, the punching shear resistance of the slab is a main factor. It can be increased in the vicinity of the slab-column connection with punching shear reinforcement, like bent up bars or shear studs, to bear the high reaction forces. However, the usage of punching shear reinforcement requires the knowledge of special design rules and often leads to problems and deficiencies in construction.</p><p>Fiber reinforced concrete seems to be a promising alternative to conventional punching shear reinforcement. To investigate the load bearing behavior of the slab-column connection using fiber reinforced concrete, a total of eight punching shear tests were performed. The specimens were realized with a typical top and bottom flexural reinforcement, but without punching shear reinforcement. Varied parameters were the slab thickness with 250 mm and 300 mm and the fiber content V<sub>f</sub> with 0.5 Vol.-% and 1.0 Vol.-%. To investigate the influence of modern fiber types, normal- and high-strength steel fibers with normal- and double-hooked-ends were used.</p><p>In all eight experimental tests, the intended punching shear failure was achieved. The capable load using fiber reinforced concrete increased by 20 % to 50 % compared to the reference tests without steel fibers, depending on the fiber type and the fiber content V<sub>f</sub>. Additionally, this load increase was accompanied by a significant improvement in ductility. The post-cracking behavior was noticeably influenced by the used steel fiber type. An influence of the slab thickness or steel fiber type on the shear strength contributed by the fiber reinforced concrete could not be determined.</p>

Bending Toughness of Zinc Phosphate Steel Fiber Reinforced Concrete before and after Corrosion

2010 ◽  
Vol 168-170 ◽  
pp. 1762-1766
Author(s):  
Min Sun ◽  
Di Jiang Wen ◽  
Peng Xie
Keyword(s):  
Reinforced Concrete ◽  
Zinc Phosphate ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Before And After ◽  
Interface Bond Strength ◽  
Interface Bond

The interface bond between steel fibers and concrete matrix is the key of carrying capacity of steel fiber reinforced concrete(SFRC). In marine tidal fluctuation zone and splashed area, steel fibers will be rusty, and the bending toughness of SFRC was weakened. In this study, we tried to improve corrosion resistance of steel fiber and the interface bond strength by depositing zinc phosphate coating on steel fiber. These zinc phosphate steel fiber reinforced concrete(ZSFRC) have higher anti-corrosion ability. After corrosion they still have higher bending toughness than common SFRC.

Damage Behavior of Steel Fiber Reinforced and Polymer Modified Concrete under Impact Loading

2007 ◽  
Vol 348-349 ◽  
pp. 889-892 ◽  
Author(s):  
Yi Ping Liu ◽  
Li Qun Tang ◽  
Xiao Qing Huang
Keyword(s):  
Impact Loading ◽  
Damage Evolution ◽  
Steel Fiber ◽  
Split Hopkinson Pressure Bar ◽  
Early Stage ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Polymer Modified Concrete ◽  
The Impact

Damage behaviors of plain concrete (PC), steel fiber reinforced concrete (SFRC), steel fiber reinforced and polymer modified concrete (SFRPMC) are studied in this paper by use of a Split Hopkinson Pressure Bar (SHPB). Three kinds of concrete materials appear obvious strain rate strengthening effects. SFRPMC appears a better resistance and energy absorption ability. A rate-dependent damage model is suggested to depict the impact damage evolution of three kinds of materials under different impact velocities. The simulation results showed the theoretical model could well describe the dynamic behaviors of the three kinds of materials, and steel fibers attribute more to resist crack develop in early stage, “bridge effect” of steel fibers slow up the damage evolution in SFRC, with the addition of polymer, the internal structures of SFRPMC were modified, SFRPMC gains better ductility, and appears a kind of “softening effect”, which makes the damage in SFRPMC develop more slowly than that in PC and SFRC under impact loading.

Compressive Strength and Splitting Tensile Strength of Steel Fiber Reinforced Ultra High Strength Concrete (SFRC)

2010 ◽  
Vol 34-35 ◽  
pp. 1441-1444 ◽  
Author(s):  
Ju Zhang ◽  
Chang Wang Yan ◽  
Jin Qing Jia
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
High Strength ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Strength Concrete

This paper investigates the compressive strength and splitting tensile strength of ultra high strength concrete containing steel fiber. The steel fibers were added at the volume fractions of 0%, 0.5%, 0.75%, 1.0% and 1.5%. The compressive strength of the steel fiber reinforced ultra high strength concrete (SFRC) reached a maximum at 0.75% volume fraction, being a 15.5% improvement over the UHSC. The splitting tensile strength of the SFRC improved with increasing the volume fraction, achieving 91.9% improvements at 1.5% volume fraction. Strength models were established to predict the compressive and splitting tensile strengths of the SFRC. The models give predictions matching the measurements. Conclusions can be drawn that the marked brittleness with low tensile strength and strain capacities of ultra high strength concrete (UHSC) can be overcome by the addition of steel fibers.

scholarly journals Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

2012 ◽  
Vol 2 (3) ◽  
Author(s):  
Farhad Aslani ◽  
Shami Nejadi
Keyword(s):  
Steel Fiber ◽  
Steel Reinforcement ◽  
Steel Fibers ◽  
Fiber Types ◽  
Reinforcing Steel ◽  
Structural Elements ◽  
Fiber Reinforced ◽  
Self Compacting Concrete ◽  
Inclined Angle ◽  
Bond Characteristics

AbstractSteel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers, information is hardly available in this area. In this study, bond characteristics of deformed reinforcing steel bars embedded in SFRSCC is investigated secondly.

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