Direct tensile behavior of amorphous metallic fiber-reinforced cementitious composites: Effect of fiber length, fiber volume fraction, and strain rate

2019 ◽  
Vol 177 ◽  
pp. 107430 ◽  
Author(s):  
Hongseop Kim ◽  
Gyuyong Kim ◽  
Sangkyu Lee ◽  
Gyeongcheol Choe ◽  
Takafumi Noguchi ◽  
...  
2020 ◽  
Vol 10 (6) ◽  
pp. 2072
Author(s):  
Seungwon Kim ◽  
Cheolwoo Park ◽  
Yongjae Kim

Conventional concrete is a brittle material with a very low tensile strength as a result of compressive strength and tensile strain. In this study, the flexural behavior characteristics of slurry-infiltrated fiber-reinforced cementitious composites (SIFRCCs) based on slurry-infiltrated fiber concrete (SIFCON), such as high-performance fiber-reinforced cementitious composites (HPFRCCs), were analyzed to maximize the fiber volume fraction and increase resistance to loads with very short working times (such as explosions or impacts). For extensive experimental variables, one fiber aspect ratio and three fiber volume fractions (6%, 5%, and 4%) were designed, and the flexural toughness and strength were figured out with respect to variables. A maximum flexural strength of 45 MPa was presented for a fiber volume fraction of 6%, and it was found that by increasing the fiber volume fraction the flexural strength and toughness increased. The test results with respect to fiber volume fraction revealed that after the initial crack, the load of SIFRCCs frequently increased because of the high fiber volume fraction. In addition to maximum strength, acceptable strength was found, which could have a positive effect on brittle fractures in structures where an accidental load is applied (such as an impact or explosion).


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3335 ◽  
Author(s):  
Seungwon Kim ◽  
Dong Joo Kim ◽  
Sung-Wook Kim ◽  
Cheolwoo Park

Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.


2013 ◽  
Vol 438-439 ◽  
pp. 270-274
Author(s):  
Hai Long Wang ◽  
Guang Yu Peng ◽  
Yue Jing Luo ◽  
Xiao Yan Sun

Engineered cementitious composite (ECC) is a representative of the new generation of high performance fiber reinforced cementitious composites. To reveal the influence of mineral admixtures on the tensile mechanical characteristics of polyvinyl alcohol fiber reinforced engineered cementitious composites (PVA-ECC), the tensile properties of PVA-ECC with replacing cement by a significant amount of fly ash (FA), silica fume (SF) and metakaolin (MK) was experimentally investigated. Uniaxial tensile experiment was carried out using rectangular thin plate with sizes of 400×100×15mm3. Results from uniaxial tensile tests show that these mineral admixtures can improve the properties of PVA-ECC. The composite can achieve an ultimate strain of 2.0%, as well as an ultimate strength of 4.0MPa, with a moderate fiber volume fraction of 2.0%. In addition, the composites with FA, SF and MK show saturated multiple cracking characteristics with crack width at ultimate strain limited to below 175μm.


2010 ◽  
Vol 34-35 ◽  
pp. 1445-1448 ◽  
Author(s):  
Shu Guang Liu ◽  
Cun He ◽  
Chang Wang Yan ◽  
Xiao Ming Zhao

This paper mainly studies early anti-cracking of cementitious composites containing polyvinyl alcohol (PVA) fiber and fly ash (FA). The PVA fibers were added at the volume fractions of 0%, 0.25%, 0.5%, 1.0% and 2.0%. The percentages of FA used in the experiment were 0% and 15%. Experimental results show that the maximum crack width and total crack area can be reduced with the increase of volume fraction of PVA fiber, and that no crack appeared at the volume fraction of 2.0%. The reducing tendency of crack width and total crack area kept constant with addition of FA, but reducing amplitude decreased. When the PVA fiber volume fraction remains constant, the early anti-cracking properties of cementitious composites containing PVA fiber and common cement are superior to one containing PVA fiber and FA. Conclusions can be drawn that the early anti-cracking properties of cementitious composites can be improved by PVA fiber.


2017 ◽  
Vol 09 (01) ◽  
pp. 1750002 ◽  
Author(s):  
Minzu Liang ◽  
Fangyun Lu ◽  
Xiangyu Li

The quasi-static and dynamic compression responses and failure of fiber-reinforced syntactic foams were investigated. The role of fiber volume fraction on the compression response of syntactic foams was examined in terms of mechanical behavior and energy absorption under both quasi-static and dynamic conditions. Results showed that the mechanical behavior and energy absorption of the reinforced specimens increased with increasing fiber volume fraction. The syntactic foams exhibited distinct strain rate sensitivity; and their yield strength and elastic modulus increased by 41.1% and 85.1%, respectively, as strain rate increased from 0.0011 s[Formula: see text] to 1070 s[Formula: see text]. The deformation and failure processes of the syntactic foams were also examined, and the underlying mechanisms were discussed.


2021 ◽  
Vol 879 ◽  
pp. 284-293
Author(s):  
Norliana Bakar ◽  
Siew Choo Chin

Fiber Reinforced Polymer (FRP) made from synthetic fiber had been widely used for strengthening of reinforced concrete (RC) structures in the past decades. Due to its high cost, detrimental to the environment and human health, natural fiber composites becoming the current alternatives towards a green and environmental friendly material. This paper presents an investigation on the mechanical properties of bamboo fiber reinforced composite (BFRC) with different types of resins. The BFRC specimens were prepared by hand lay-up method using epoxy and vinyl-ester resins. Bamboo fiber volume fractions, 30%, 35%, 40%, 45% and 50% was experimentally investigated by conducting tensile and flexural test, respectively. Results showed that the tensile and flexural strength of bamboo fiber reinforced epoxy composite (BFREC) was 63.2% greater than the bamboo fiber reinforced vinyl-ester composite (BFRVC). It was found that 45% of bamboo fiber volume fraction on BFREC exhibited the highest tensile strength compared to other BFRECs. Meanwhile, 40% bamboo fiber volume fraction of BFRVC showed the highest tensile strength between bamboo fiber volume fractions for BFRC using vinyl-ester resin. Studies showed that epoxy-based BFRC exhibited excellent results compared to the vinyl-ester-based composite. Further studies are required on using BFRC epoxy-based composite in various structural applications and strengthening purposes.


2006 ◽  
Vol 33 (6) ◽  
pp. 726-734 ◽  
Author(s):  
Fariborz Majdzadeh ◽  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia

The purpose of this study was to investigate the influence of fiber reinforcement on the shear capacity of reinforced concrete (RC) beams. Both steel and synthetic fibers at variable volume fractions were investigated. Two series of tests were performed: structural tests, where RC beams were tested to failure under an applied four-point load; and materials tests, where companion fiber-reinforced concrete (FRC) prisms were tested under direct shear to obtain material properties such as shear strength and shear toughness. FRC test results indicated an almost linear increase in the shear strength of concrete with an increase in the fiber volume fraction. Fiber reinforcement enhanced the shear load capacity and shear deformation capacity of RC beams, but 1% fiber volume fraction was seen as optimal; no benefits were noted when the fiber volume fraction was increased beyond 1%. Finally, an equation is proposed to predict the shear capacity of RC beams.Key words: shear strength, fiber-reinforced concrete, RC beam, stirrups, energy absorption capacity, steel fiber, synthetic fiber.


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