scholarly journals Increasing the Performance of a Fiber-Reinforced Concrete for Protective Facilities

Fibers ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 64
Author(s):  
Roman Fediuk ◽  
Mugahed Amran ◽  
Sergey Klyuev ◽  
Aleksandr Klyuev
Keyword(s):  
Reinforced Concrete ◽  
Impact Strength ◽  
Impact Energy ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Secondary Cracks ◽  
Wide Range ◽  
Long Time ◽  
The Impact ◽  
Hardening Coefficient

The use of fiber in cement materials is a promising and effective replacement for bar reinforcement. A wide range of fiber-reinforced concretes based on composite binders with increased impact strength characteristics have been developed. The synthesized composites included the composite binder made of Portland cement, silica, and carbonate additives. Basalt and steel were used as fibers. The nature of the influence of the composition and manufacturing technology of cement composites on the dynamic hardening coefficient has been established, while the growth of these indicators is achieved by creating a denser interfacial transition zone between the cement paste, aggregate, and fiber as a result of improving the homogeneity of the concrete mixture and controlling the consistency. Workability indicators (slump flow up to 730 mm; spreading time up to a diameter of 50 cm is up to 3 s) allow them to be classified as self-compacting concrete mixtures. An increase in the values of the impact strength coefficient by a factor of 5.5, the dynamic hardening coefficient by almost 70% as a result of interfacial interaction between fibers and binder matrix in the concrete composite, as well as absorption of impact energy by fiber, was revealed. The formula describing the effect of the loading rate on the coefficient of dynamic hardening of fiber-reinforced concrete has been refined. The fracture processes of the obtained materials have been established: after the initiation of primary cracks, the structure of the composite absorbs impact energy for a long time, while in the inelastic range (the onset of cracking and peak loads), a large number of secondary cracks appear.

scholarly journals Experimental Study on Hybrid Effect Evaluation of Fiber Reinforced Concrete Subjected to Drop Weight Impacts

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2563 ◽  
Author(s):  
Jun Feng ◽  
Weiwei Sun ◽  
Hongzhou Zhai ◽  
Lei Wang ◽  
Haolin Dong ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Polyvinyl Alcohol ◽  
Impact Energy ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Hybrid Effect ◽  
Polyvinyl Alcohol Fiber ◽  
The Impact

In this paper, the impact energy potential of hybrid fiber reinforced concrete (HFRC) was explored with different fiber mixes manufactured for comparative analyses of hybridization. The uniaxial compression and 3-point bending tests were conducted to determine the compressive strength and flexural strength. The experimental results imply that the steel fiber outperforms the polypropylene fiber and polyvinyl alcohol fiber in improving compressive and flexural strength. The sequent repeated drop weight impact tests for each mixture concrete specimens were performed to study the effect of hybrid fiber reinforcement on the impact energy. It is suggested that the steel fiber incorporation goes moderately ahead of the polypropylene or polyvinyl alcohol fiber reinforcement in terms of the impact energy improvement. Moreover, the impact toughness of steel-polypropylene hybrid fiber reinforced concrete as well as steel-polyvinyl alcohol hybrid fiber reinforced concrete was studied to relate failure and first crack strength by best fitting. The impact toughness is significantly improved due to the positive hybrid effect of steel fiber and polymer fiber incorporated in concrete. Finally, the hybrid effect index is introduced to quantitatively evaluate the hybrid fiber reinforcement effect on the impact energy improvement. When steel fiber content exceeds polyvinyl alcohol fiber content, the corresponding impact energy is found to be simply sum of steel fiber reinforced concrete and polyvinyl alcohol fiber reinforced concrete.

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.    

Concrete and Fiber Reinforced Concrete Subjected to Impact Loading

1985 ◽  
Vol 64 ◽  
Author(s):  
Surendra P. Shah
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Basic Material ◽  
Strain History ◽  
Moderate Increase ◽  
Fiber Reinforced ◽  
The Impact

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.

scholarly journals Effect of Strengthening Methods on Two-Way Slab under Low-Velocity Impact Loading

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5603
Author(s):  
Sun-Jae Yoo ◽  
Tian-Feng Yuan ◽  
Se-Hee Hong ◽  
Young-Soo Yoon
Keyword(s):  
Reinforced Concrete ◽  
High Performance Concrete ◽  
Impact Load ◽  
Reaction Force ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Low Velocity Impact ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
The Impact

In this study, the performance of reinforced concrete slabs strengthened using four methods was investigated under impact loads transferred from the top side to bottom side. The top and bottom sides of test slabs were strengthened by no-slump high-strength, high-ductility concrete (NSHSDC), fiber-reinforced-polymer (FRP) sheet, and sprayed FRP, respectively. The test results indicated that the test specimens strengthened with FRP series showed a 4% increase in reaction force and a decrease in deflection by more than 20% compared to the non-strengthened specimens. However, the specimen enhanced by the NSHSDC jacket at both the top and bottom sides exhibited the highest reaction force and energy dissipation as well as the above measurements because it contains two types of fibers in the NSHSDC. In addition, the weight loss rate was improved by approximately 0.12% for the NSHSDC specimen, which was the lowest among the specimens when measuring the weight before and after the impact load. Therefore, a linear relationship between the top and bottom strengthening of the NSHSDC and the impact resistance was confirmed, concluding that the NSHSDC is effective for impact resistance when the top and bottom sides are strengthened. The results of the analysis of the existing research show that the NSHSDC is considered to have high impact resistance, even though it has lower resistance than the steel fiber reinforced concrete and ultra-high-performance-concrete, it can be expected to further studies on strengthening of NSHSDC.

scholarly journals Abrasion Behavior of Steel-Fiber-Reinforced Concrete in Hydraulic Structures

2020 ◽  
Vol 10 (16) ◽  
pp. 5562 ◽  
Author(s):  
Yu-Wen Liu ◽  
Yu-Yuan Lin ◽  
Shih-Wei Cho
Keyword(s):  
Reinforced Concrete ◽  
Abrasion Resistance ◽  
Steel Fiber ◽  
Cementitious Material ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Hydraulic Structures ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
The Impact

This study investigated two types of abrasion resistance of steel–fiber-reinforced concrete in hydraulic structures, friction abrasion and impact abrasion using the ASTM C1138 underwater test and the water-borne sand test, respectively. Three water-to-cementitious-material ratios (0.50, 0.36, and 0.28), two impact angles (45° and 90°), plain concrete, and steel–fiber-reinforced concrete were employed. Test results showed that the abrasive action and principal resistance varied between the two test methods. The average impact abrasion rates (IARs) of concrete were approximately 8–17 times greater than the average friction abrasion rate (FARs). In general, the impact abrasion loss of the concrete surface impacted at a vertical angle was higher than that of impacted at a 45 degree angle. Moreover, the average FAR and IAR decreased when the concrete was reinforced with steel fibers. The steel fibers acted as shields to prevent the concrete material behind the fibers from abrasion, thus improving abrasion resistance. In both the underwater and waterborne sand flow methods, the resistance to abrasion of concrete without steel fibers increased as the water/cementitious material ratio (w/cm) decreased, and the concrete compressive strength also increased.

Properties of Polymeric Fiber-Reinforced Concrete

1996 ◽  
Vol 1532 (1) ◽  
pp. 27-35
Author(s):  
P. Balaguru ◽  
Anil Khajuria
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Strength ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Modulus Of Rupture ◽  
Unit Weight ◽  
Fiber Reinforced ◽  
Fiber Volume

The mechanical properties of lightweight and normal concrete containing nylon polymeric fibers are presented. Fiber reinforced concrete made with nylon fibers was evaluated. The 19-mm-long fibers were in single filament form. The control concrete was designed for a compressive strength of 20 MPa. The primary independent variable was fiber volume fraction. The response variables were air content, unit weight of fresh concrete, compressive strength, modulus of rupture (flexural strength) and toughness, splitting tensile strength, and impact strength. The addition of fibers decreased the slump values. The decrease was negligible at fiber contents of 0.45 and 0.6 kg/m3. The fibers distributed well in the matrix. Fibers could be directly added in the mixer. The effect fibers had on unit weight of concrete is negligible. Addition of fibers up to 2.4 kg/m3 did not change the compressive, flexural, and splitting tensile strengths appreciably. Impact strength and flexural toughness increased consistently with the increase of fiber volume fraction.

scholarly journals Effect of fiber ratio on the impact behavior of polypropylene fiber reinforced samples

2021 ◽  
Vol 4 (4) ◽  
pp. 239-248
Author(s):  
Mehmet Fatih Şahan ◽  
Fatih Ali Öncel ◽  
İsmail Ünsal
Keyword(s):  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Impact Behavior ◽  
Fiber Reinforced ◽  
Static Compression ◽  
Concrete Mixtures ◽  
The Impact ◽  
Polypropylene Fiber Reinforced Concrete ◽  
Control Samples

This study investigated the effect of fiber ratio on the impact behavior of polypropylene fiber reinforced concrete cube and beam samples. Plain concrete mixtures for control samples and polypropylene fiber-reinforced concrete mixtures with fiber ratios of %0.22, %0.44, and %0.66 by volume were prepared. An instrumented drop-weight impact system was used for the dynamic tests. Static compression tests, three-point bending tests, and impact tests were performed on beam samples (with the dimension of 100×100×500 mm). Static compression and impact tests were performed on cube samples (with the size of 100 mm). It was observed that the fracture properties of polypropylene fiber reinforced concrete for both cube and beam samples were better than the control samples under impact. The crack width in the beams under the impact decreased with the increase in polypropylene fiber ratio. The cube and beam concrete samples reinforced with polypropylene fibers absorbed the impact energy better than the control samples.

scholarly journals Mechanical Properties of Aramid/Carbon Hybrid Fiber-Reinforced Concrete

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5881
Author(s):  
Yeou-Fong Li ◽  
Hsin-Fu Wang ◽  
Jin-Yuan Syu ◽  
Gobinathan Kadagathur Ramanathan ◽  
Ying-Kuan Tsai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Mechanical Strength ◽  
Carbon Fibers ◽  
Coupling Agent ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
The Impact

In this study, aramid fiber (Kevlar® 29 fiber) and carbon fiber were added into concrete in a hybrid manner to enhance the static and impact mechanical properties. The coupling agent presence on the surface of carbon fibers was spotted in Scanning Electron Microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) graphs. The carbon fiber with a coupling agent affected the mechanical strength of the reinforced concrete. At 1% fiber/cement weight percentage, the hybrid fiber-reinforced concrete (HFRC) prepared using Kevlar fiber and carbon fiber of 12 and 24 mm in length under different mix proportions was investigated to determine the maximum mechanical strengths. From the test results, the mechanical strength of the HFRC attained better performance than that of the concrete with only Kevlar or carbon fibers. Foremost, the mix proportion of Kevlar/carbon fiber (50–50%) significantly improved the compressive, flexural, and splitting tensile strengths. Under different impact energies, the impact resistance of the HFRC specimen was much higher than that of the benchmark specimen, and the damage of the HFRC specimens was examined with an optical microscope to identify slippage or rupture failure of the fiber in concrete.

Sign in / Sign up

Export Citation Format

Share Document