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.

Study on Dynamic Mechanical Properties of Carbon Fiber Reinforced Concrete

2020 ◽  
Vol 976 ◽  
pp. 180-185
Author(s):  
Gao Jie Liu ◽  
Er Lei Bai ◽  
Jin Yu Xu ◽  
Bo Xu Meng ◽  
Teng Jiao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Concrete ◽  
Peak Strain ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Deformation Properties ◽  
Carbon Fiber Reinforced ◽  
The Impact

The strength and deformation properties of carbon fiber reinforced concrete under different fiber volume loadings under impact loading were studied by using the ɸ100 mm split Hopkinson pressure bar (SHPB) test system. The results show that after the carbon fiber is added, the stress-strain curve of the specimen shows the platform section at the peak stress. The strength and peak strain of the concrete under the impact load increase first and then decrease with the increase of the carbon fiber volume. Trend, when the carbon fiber volume is 0.2%, the impact mechanical properties of concrete are significantly improved.

scholarly journals Static and Dynamic Performances of Chopped Carbon-Fiber-Reinforced Mortar and Concrete Incorporated with Disparate Lengths

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 972
Author(s):  
Yeou-Fong Li ◽  
Kun-Fang Lee ◽  
Gobinathan Kadagathur Ramanathan ◽  
Ta-Wui Cheng ◽  
Chih-Hong Huang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Blast Wave ◽  
Carbon Fibers ◽  
Impact Test ◽  
Free Fall ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced ◽  
The Impact

The impact load, such as seismic and shock wave, sometimes causes severe damage to the reinforced concrete structures. This study utilized different lengths of chopped carbon fibers to develop a carbon-fiber-reinforced mortar (CFRM) and carbon-fiber-reinforced concrete (CFRC) with high impact and anti-shockwave resistance. The different lengths (6, 12, and 24 mm) of chopped carbon fibers were pneumatically dispersed and uniformly mixed into the cement with a 1% weight proportion. Then the CFRM and CFRC specimens were made for static and dynamic tests. The compressive and flexural strengths of the specimens were determined by using the standard ASTM C39/C 39M and ASTM C 293-02, respectively. Meanwhile, a free-fall impact test was done according to ACI 544.2R-89, which was used to test the impact resistances of the specimens under different impact energies. The CFRM and CFRC with a length of 6 mm exhibit maximum compressive strength. Both flexural and free-fall impact test results show that the 24 mm CFRM and CFRC enhances their maximum flexural strength and impact numbers more than the other lengths of CFRM, CFRC, and the benchmark specimens. After impact tests, the failure specimens were observed in a high-resolution optical microscope, to identify whether the failure mode is slippage or rupture of the carbon fiber. Finally, a blast wave explosion test was conducted to verify that the blast wave resistance of the 24 mm CFRC specimen was better than the 12 mm CFRC and benchmark specimens.

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.    

scholarly journals Experimental Study on Mechanical Properties of High Performance Hybrid Fiber Concrete for Shaft Lining

2021 ◽  
Vol 11 (17) ◽  
pp. 7926
Author(s):  
Qian Zhang ◽  
Wenqing Zhang ◽  
Yu Fang ◽  
Yongjie Xu ◽  
Xianwen Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Reference Group ◽  
Splitting Tensile Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Fiber Concrete ◽  
Shaft Lining

In order to solve the problem of highly brittle shaft lining under dynamic loading, a combination of hybrid fiber concrete mixed with steel and polypropylene fiber is proposed to make shaft lining. C60, the concrete commonly used in shaft lining, was selected as the reference group. The static mechanical properties, dynamic mechanical properties, and crack failure characteristics of the hybrid fiber concrete were experimentally studied. The test results showed that compared to the reference group concrete, the compressive strength of the hybrid fiber-reinforced concrete did not significantly increase, but the splitting tensile strength increased by 60.4%. The split Hopkinson compression bar results showed that the optimal group peak stress and peak strain of the hybrid fiber concrete increased by 58.2% and 79.2%, respectively, and the dynamic toughness increased by 68.1%. The strain distribution before visible cracks was analyzed by the DIC technology. The results showed that the strain dispersion phenomenon of the fiber-reinforced concrete specimen was stronger than that of the reference group concrete. By comparing the crack failure forms of the specimens, it was found that compared to the reference group concrete, the fiber-reinforced concrete specimens showed the characteristics of continuous and slow ductile failure. The above results suggest that HFRC has significantly high dynamic splitting tensile strength and compressive deformation capacity, as well as a certain anti-disturbance effect. It is an excellent construction material for deep mines under complex working conditions.

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