scholarly journals Development of Steel Fiber-Reinforced Expanded-Shale Lightweight Concrete with High Freeze-Thaw Resistance

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mingshuang Zhao ◽  
Xiaoyan Zhang ◽  
Wenhui Song ◽  
Changyong Li ◽  
Shunbo Zhao
Keyword(s):  
Steel Fiber ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Content Volume ◽  
Steel Fibers ◽  
Fine Aggregate ◽  
Test Results ◽  
Fiber Reinforced ◽  
Freeze Thaw ◽  
Expanded Shale

For the popularized structural application, steel fiber-reinforced expanded-shale lightweight concrete (SFRELC) with high freeze-thaw resistance was developed. The experimental study of this paper figured out the effects of air-entraining content, volume fraction of steel fibers, and fine aggregate type. Results showed that while the less change of mass loss rate was taken place for SFRELC after 300 freeze-thaw cycles, the relative dynamic modulus of elasticity and the relative flexural strength presented clear trends of freeze-thaw resistance of SFRELC. The compound effect of the air-entraining agent and the steel fibers was found to support the SFRELC with high freeze-thaw resistance, and the mechanisms were explored with the aid of the test results of water penetration of SFRELC. The beneficial effect was appeared from the replacement of lightweight sand with manufactured sand. Based on the test results, suggestions are given out for the optimal mix proportion of SFRELC to satisfy the durability requirement of freeze-thaw resistance.

scholarly journals The Effect of Steel Fibers Type and Content on the Development of Fresh and Hardened Properties and Durability of Selfconsolidating Concrete

2021 ◽  
Author(s):  
Nirmal Tamrakar
Keyword(s):  
Compressive Strength ◽  
Bond Strength ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Ring Test ◽  
Fiber Reinforced ◽  
Chloride Permeability ◽  
Freeze Thaw

Steel fiber reinforced self-consolidated concrete (SFRSCC) has the advantages of both selfconsolidated concrete and fiber reinforced concrete. Thirteen concrete mixtures (with short and long steel fiber) were prepared including control mix. The steel fiber volume fraction varied from 0 to 2.4% by the volume of concrete. The fresh properties of SCC were evaluated using slump flow test, J-ring test, V-funnel test and L-Box test. Bond strength, compressive strength and flexural tests were performed in order to investigate mechanical properties. Water sorptivity, water absorption and porosity, rapid chloride permeability test (RCPT), corrosion and freezethaw cycles tests were performed in order to investigate the durability properties. Bond strength gain of 244% with respect to control mix was observed. Moreover, the compressive strength and MOR gained 45% and 127%, respectively. There was no significant weight loss of the concrete specimen after freeze-thaw cycles for concrete mixture with steel fibers. However, flexural toughness was reduced after freeze-thaw cycles.

scholarly journals Complete Stress–Strain Curves of Self-Compacting Steel Fiber Reinforced Expanded-Shale Lightweight Concrete under Uniaxial Compression

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2979 ◽  
Author(s):  
Zhao ◽  
Zhang ◽  
Shang ◽  
Fu ◽  
Zhang ◽  
...  
Keyword(s):  
Uniaxial Compression ◽  
Steel Fiber ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Compressive Strain ◽  
Strain Curve ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Expanded Shale

To expand the structural application of steel fiber reinforced expanded-shale lightweight concrete (SFRELC), a self-compacting SFRELC with high-workability was developed based on previous research. As part of the investigation, the present study focuses on the adaptability of formulas used for the complete stress–strain curves of steel fiber reinforced lightweight-aggregate concrete and conventional concrete under uniaxial compression. On the basis of mix proportion of SFRELC, self-compacting SFRELC was designed with the volume fraction of steel fiber as 0%, 0.4%, 0.8%, 1.2%, 1.6%, and 2.0%. Eighteen cylindrical specimens with dimensions of Φ150 mm × 300 mm were tested to measure the uniaxial compressive stress–strain curves of self-compacting SFRELC. Results indicated that, with the increasing volume fraction of steel fiber, the compressive strain at the peak-stress of the stress–strain curve increased, while the slope of the descending portion decreased. This increased the energy absorption of self-compacting SFRELC with a higher compression toughness. With a comparison of test results between four groups of calculation models, a group of formulas is selected to express the complete stress–strain curves of self-compacting SFRELC under uniaxial compression.

scholarly journals Bond of Ribbed Steel Bar in High-Performance Steel Fiber Reinforced Expanded-Shale Lightweight Concrete

Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 582
Author(s):  
Mingshuang Zhao ◽  
Guirong Liu ◽  
Lingli Liu ◽  
Yanyan Zhang ◽  
Kang Shi ◽  
...  
Keyword(s):  
Bond Strength ◽  
High Performance ◽  
Steel Fiber ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Bond Stress ◽  
Fiber Reinforced ◽  
Bond Slip ◽  
Steel Bar ◽  
Expanded Shale

For the structural application of high-performance Steel Fiber Reinforced Expanded-shale Lightweight Concrete (SFRELC), a reliable bond of ribbed steel bar should be ensured. In this paper, an experimental study was carried out on the bond properties of ribbed steel bar embedded in SFRELC by the direct pull-out test. The SFRELC was produced with a strength grade of 35 MPa and a volume fraction of steel fiber as 0%, 0.8%, 1.2%, 1.6% and 2.0%, respectively. Fifteen groups of specimens were made with a central placed steel bar with diameter of 14 mm, 20 mm and 28 mm, respectively. Complete bond stress-slip curves were determined for each group of specimens, and the characteristic values of bond-stress and slip at key points of the curves were ascertained. Results show that the bond strength, peak-slip and residual bond strength increased with the increase of the volume fraction of steel fiber. With the increase of steel bar diameter, bond strength decreased while the peak-slip increased, and the descending curves became sharp with a decreased residual bond strength. Formulas for calculating the bond strength and peak-slip were proposed. The relationships were determined for the splitting bond strength, residual bond strength with the bond strength, the splitting bond slip and residual bond slip with the peak-slip. Combined with rational fitting analyses of bond strength and slip, a constitutive model was selected for predicting the bond stress-slip of ribbed steel bar in SFRELC.

scholarly journals The Effect of Steel Fibers Type and Content on the Development of Fresh and Hardened Properties and Durability of Selfconsolidating Concrete

2021 ◽  
Author(s):  
Nirmal Tamrakar
Keyword(s):  
Compressive Strength ◽  
Bond Strength ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Ring Test ◽  
Fiber Reinforced ◽  
Chloride Permeability ◽  
Freeze Thaw

Steel fiber reinforced self-consolidated concrete (SFRSCC) has the advantages of both selfconsolidated concrete and fiber reinforced concrete. Thirteen concrete mixtures (with short and long steel fiber) were prepared including control mix. The steel fiber volume fraction varied from 0 to 2.4% by the volume of concrete. The fresh properties of SCC were evaluated using slump flow test, J-ring test, V-funnel test and L-Box test. Bond strength, compressive strength and flexural tests were performed in order to investigate mechanical properties. Water sorptivity, water absorption and porosity, rapid chloride permeability test (RCPT), corrosion and freezethaw cycles tests were performed in order to investigate the durability properties. Bond strength gain of 244% with respect to control mix was observed. Moreover, the compressive strength and MOR gained 45% and 127%, respectively. There was no significant weight loss of the concrete specimen after freeze-thaw cycles for concrete mixture with steel fibers. However, flexural toughness was reduced after freeze-thaw cycles.

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.

Experiment Study on the Frost Resistance of Steel Fiber Reinforced Concrete on the Microstructure

2011 ◽  
Vol 368-373 ◽  
pp. 357-360
Author(s):  
Lei Jiang ◽  
Di Tao Niu ◽  
Min Bai
Keyword(s):  
Reinforced Concrete ◽  
Frost Resistance ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Nacl Solution ◽  
Steel Fiber Reinforced Concrete ◽  
Freeze Thaw ◽  
Damage Rate

Based on the fast freeze-thaw test in 3.5% NaCl solution, the frost resistance of steel fiber reinforced concrete (SFRC) was studied in this paper. On the basis of scanning electron microscope (SEM) and mercury intrusion method, the microstructure and pore structure of SFRC was analysed. The reinforced mechanism of SFRC under the cooperation of freeze-thaw and NaCl solution was discussed. The test results show that adding appropriate amount of steel fibers into concrete can reduce the pore porosity and improve the compactness of concrete. The effects of steel fiber with proper volume fraction can inhibit the peeling of the concrete and reduce its damage rate. The volume of steel fiber on the frost-resisting property of SFRC is obvious.

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.

Experiment Study on the Frost Resistance of Steel Fiber Reinforced Concrete

2010 ◽  
Vol 150-151 ◽  
pp. 243-246 ◽  
Author(s):  
Lei Jiang ◽  
Di Tao Niu ◽  
Min Bai
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Early Stage ◽  
Variable Parameter ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Freeze Thaw ◽  
Splitting Strength

In order to study various factor affecting durability of steel fiber reinforced concrete (SFRC), basic experimental research that combine the action of freezing-thawing cycles and deicing salt to SFRC was conducted. In the experiment, the volume fraction of steel fiber and number of freeze-thaw circulation are taken as variable parameter. Based on the different numbers of freeze-thaw circulation, weight losing of SFRC, splitting strength and the dynamic modulus of elasticity were measured. Furthermore, the reinforced mechanism of the SFRC under the action of freeze-thaw was analysed. The test results show that after adding a certain amount of steel fiber to the concrete, cracks in concrete at early stage are effectively prevented and the permeability of concrete is obviously reduced, thus the durability of concrete is improved. The reinforced actions of steel fiber on splitting strength of concrete are notable and the influence of steel fiber volume fraction on the frost-resisting property is obvious. On the contrary, the negative effects of steel fiber with high volume fraction on the splitting strength of concrete exist. The best performance of SFRC can be got when the steel fiber quantity is 1.5%.

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