scholarly journals Evaluating of Electromagnetic Shielding Characteristics of Reinforced Concrete Using Reinforcing Details

2020 ◽  
Vol 20 (5) ◽  
pp. 245-254
Author(s):  
JinSeok Choi ◽  
TianFeng Yuan ◽  
SeHee Hong ◽  
YoungSoo Yoon
Keyword(s):  
Reinforced Concrete ◽  
Frequency Band ◽  
Steel Fiber ◽  
Low Frequency ◽  
Volume Ratio ◽  
Experimental Tests ◽  
Electromagnetic Shielding ◽  
Fiber Reinforced Concrete ◽  
Shielding Effectiveness ◽  
Fiber Volume

In this study, experimental tests were performed to determine the electromagnetic shielding characteristics of reinforced concrete based on the thickness of concrete and rebar. In addition, the electromagnetic shielding characteristics based on the steel-fiber volume ratio and rebar spacing of fiber-reinforced concrete were evaluated. Concrete showed significant Shielding Effectiveness (SE) in a high-frequency band with increasing thickness, but the rebar exhibited significant SE in the low-frequency band with increasing diameter, decreasing rebar spacing, and increasing layer. The SE increased with the steel fiber volume ratio, and it also increased owing to the decrease in the rebar spacing for 1.5 vol.% steel fibers.

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.

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 Using Steel Fiber-Reinforced Concrete Precast Panels for Strengthening in Shear of Beams: An Experimental and Analytical Investigation

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Pitcha Jongvivatsakul ◽  
Linh V. H. Bui ◽  
Theethawachr Koyekaewphring ◽  
Atichon Kunawisarut ◽  
Narawit Hemstapat ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Simple Formulation

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carried out to investigate the effects of fiber volume fraction, connection type, and number and diameter of bolts on the structural responses of the retrofitted beams. The current shear resisting model is also employed to discuss the test data considering shear contribution of SFRC panels. The experimental results indicate that the shear effectiveness of the beams strengthened by using SFRC panels is significantly improved. A three-dimensional (3D) nonlinear finite element (FE) analysis adopting ABAQUS is also conducted to simulate the beams strengthened in shear with SFRC panels. The investigation reveals the good agreement between the experimental and analytical results in terms of the mechanical behaviors. To complement the analytical study, a parametric study is performed to further evaluate the influences of panel thickness, compressive strength of SFRC, and bolt pattern on the performances of the beams. Based on the numerical and experimental analysis, a shear resisting model incorporating the simple formulation of average tensile strength perpendicular to the diagonal crack of the strengthened SFRC panels is proposed with the acceptable accuracy for predicting the shear contribution of the SFRC system under various effects.

Experiment Research on the Steel Fiber Reinforced Concrete in the Acid Environment

2011 ◽  
Vol 224 ◽  
pp. 224-228 ◽  
Author(s):  
Yue Qiang ◽  
Li Li ◽  
Ze Ping He
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Ph Value ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Inorganic Acid ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Volume Rate ◽  
Corrosion Coefficient

For the purpose of studying the resistance of steel fiber reinforced concrete against the corrosion of different acid, test compressive strength and flexural strength of the steel fiber reinforced concrete of different volume rate after the corrosion of organic and inorganic acid, and express experiment results with the form of comprehensive corrosion coefficient and the flexural corrosion coefficient in order to reflect the corrosion degree. The results shows that, the organic corrosion has a stronger corrosion effect on the steel fiber reinforced concrete than the inorganic acid under the environment of same PH value. When steel fiber volume rate is 1.5%, the corrosion resistance capacity of the steel fiber reinforced concrete is best.

Influence of Fiber Volume Fraction and Aggregate Size on Flexural Behavior of High Strength Steel Fiber-Reinforced Concrete (SFRC)

2013 ◽  
Vol 372 ◽  
pp. 223-226 ◽  
Author(s):  
Seok Joon Jang ◽  
Yeon Jun Yun ◽  
Hyun Do Yun
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Aggregate Size ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

The effects of aggregate size and fiber volume fraction on the flexural behavior of 70MPa high strength steel fiber-reinforced concrete (SFRC) were investigated in this work. Test variables consist of fiber volume fraction (0, 1 and 2 %) and maximum aggregate size (8, 13 and 20 mm). The prism for flexural test was 100 x 100 x 400 mm and was tested under four points loading. Flexural toughness index was measured using ASTM C 1018 procedure. Test results indicated that the addition of steel fiber to 70MPa high strength concrete improves flexural and post-cracking behaviors. This phenomenon is remarkable for SFRC mixture with higher fiber content and smaller aggregate size. Also, the flexural toughness of high strength SFRC depends primarily on fiber content. The maximum aggregate sizes were secondary in importance.

Compressive Properties of High Strength Steel Fiber Reinforced Concrete with Different Fiber Volume Fractions

2013 ◽  
Vol 372 ◽  
pp. 215-218 ◽  
Author(s):  
Hye Ran Kim ◽  
Seung Ju Han ◽  
Hyun Do Yun
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Steel ◽  
Steel Fiber ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Experimental Results ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Volume Fractions

This paper describes the experimental results of 70 MPa high strength steel fiber reinforced concrete (SFRC) with different steel fiber volume fractions in compression. The effect of steel fiber on fresh properties, compressive strength, toughness index, cracking procedure of high strength steel fiber concrete is also investigated. The steel fibers were added as the volume fractions of 0%, 0.5%, 1.0%, 1.5% and 2.0%. The cylindrical specimens with Φ100 x 200 for compressive tests were manufactured in accordance with ASTM C 39[. The experimental results showed that the slump of fresh SFRC was inversely proportional to the fiber volume fraction added to high strength concrete. As the addition of steel fiber increased, compressive strength of SFRC decreased. Inclusion of steel fiber improves compressive toughness of high strength SFRC.

Shrinkage Performance of Adherence of New Steel Fiber-Reinforced Concrete to Old Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 3569-3574
Author(s):  
Hong Qiang Cheng ◽  
Dan Ying Gao
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Shrinkage Force ◽  
The Difference

Shrinkage experiments were done to determine the influence of the volume fraction of steel fiber-reinforcement on the bonding behavior between new concrete and old concrete. The mechanics of the model of restricted shrinkage upon the adherence of new steel fiber reinforced concrete to old concrete are described. The results demonstrate that the difference of shrinkage between the new and the old concrete can been reduced by adding steel fiber to the new concrete. The decrease of shrinkage difference reduces the shrinkage force at the adhesive interface, which improves the adhesion of new concrete to old concrete and the magnitude of the decrease of shrinkage difference is correlated to the steel fiber volume fraction.

Experimental Research of Bending Capacity of Normal Section of Steel Fiber Reinforced Concrete Wall-Beams Simply Supported

2012 ◽  
Vol 193-194 ◽  
pp. 1365-1370
Author(s):  
Su Qi ◽  
Ye Zhang ◽  
Shu Hao Liu ◽  
Xiong Song
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Concrete Wall ◽  
Fiber Volume ◽  
Normal Section ◽  
Simply Supported ◽  
Reinforced Concrete Wall

Because the joists in the wall-beams are in eccentric tension during work and the concrete tensile strength is low, the bending capacity of normal section of wall-beams is not too large. Steel fibers mixed into the concrete, playing enhancement and crack-resistance roles would lead to changes in the nature of concrete materials so that it is impossible to fully use the existing research results of ordinary concrete wall-beams simply supported when studying bending behavior of normal section of steel fiber reinforced concrete wall-beams simply supported. Therefore, it is necessary to do pilot studies on bending behavior of normal section of steel fiber reinforced concrete wall-beams simply supported. Based on the vertical static load test of 12 steel fiber reinforced concrete wall-beams simply supported specimens under different fiber volume ratio conditions, the strains of steel and concrete, cracking load, failure load and development situation in the cracks were tested while working characteristics of steel fiber reinforced concrete wall-beams simply supported were studied. This paper discussed the effect of fiber volume ratio on cracking moment and ultimate moment of steel fiber reinforced concrete wall-beams simply supported, which shows that the optimum mixing amount of steel fiber is 1.2%. The conclusion is of great significance in both theory and engineering practice, and it helps to guide the application of practical engineering.

Improvement of Impact Resistance of Synthetic Macro-Fiber Reinfored Concrete

2014 ◽  
Vol 578-579 ◽  
pp. 501-504
Author(s):  
Guo Chao Wang ◽  
Bo Xin Wang
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
The Impact

The incorporation of a small amount of steel fibers or fine polypropylene fibers in concrete can increase its impact resistance. But steel fiber has the problems of corrosion, high cost and high mess. The effect of fine polypropylene fibers in inhibiting the impact crack is not effective. The research was taken to measure the properties of fresh concrete mixture of Synthetic Macro-fiber reinforced concrete. And investigated the influence of fiber length and volume fraction on the impact resistance of Synthetic Macro-fiber reinforced concrete. The results showed that these fibers could obviously improve the impact resistance of concrete. There was a best Synthetic Macro-fiber volume fraction. The length of the Synthetic Macro-fiber had a certain influence on the impact resistance of concrete.

scholarly journals Influence of Fiber Content on Shear Capacity of Steel Fiber-Reinforced Concrete Beams

Fibers ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 102 ◽  
Author(s):  
Juan Andres Torres ◽  
Eva O.L. Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume

For shear-critical structural elements where the use of stirrups is not desirable, such as slabs or beams with reinforcement congestion, steel fibers can be used as shear reinforcement. The contribution of the steel fibers to the shear capacity lies in the action of the steel fibers bridging the shear crack, which increases the shear capacity and prevents a brittle failure mode. This study evaluates the effect of the amount of fibers in a concrete mix on the shear capacity of steel fiber-reinforced concrete beams with mild steel tension reinforcement and without stirrups. For this purpose, 10 beams were tested. Five different fiber volume fractions were studied: 0.0%, 0.3%, 0.6%, 0.9%, and 1.2%. For each different steel fiber concrete mix, the concrete compressive strength was determined on cylinders and the tensile strength was determined in a flexural test on beam specimens. Additionally, the influence of fibers on the shear capacity was analyzed based on results reported in the literature, as well as based on the expressions derived for estimating the shear capacity of steel fiber-reinforced concrete beams. The outcome of these experiments is that a fiber percentage of 1.2% or fiber factor of 0.96 can be used to replace minimum stirrups according to ACI 318-14 and a 0.6% fiber volume fraction or fiber factor of 0.48 to replace minimum stirrups according to Eurocode 2. A fiber percentage of 1.2% or fiber factor of 0.96 was observed to change the failure mode from shear failure to flexural failure. The results of this study support the inclusion of provisions for steel fiber-reinforced concrete in building codes and provides recommendations for inclusion in ACI 318-14 and Eurocode 2, so that a wider adoption of steel fiber reinforced concrete can be achieved in the construction industry.

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