Relationship between Fiber Orientation and Flexural Strength in Ultra-High-Performance Fiber-Reinforced Concrete Panels

2014 ◽  
Vol 629-630 ◽  
pp. 71-78 ◽  
Author(s):  
Bo Zhou ◽  
Yuichi Uchida
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Fiber Orientation ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Three Point Bending ◽  
Concrete Panels ◽  
High Performance Fiber

In this study, the influence of fiber orientation on the flexural strength of ultra-high-performance fiber-reinforced concrete (UHPFRC) was examined. To this end, a circular UHPFRC panel measuring φ1,200 × 50 mm was cast from its center, and test specimens measuring 50 × 50 × 200 mm with 10 mm notches for three-point bending tests were cut from it with angles of 0, 30, 60 and 90° between the specimen axis and the radial direction of the panel. After the bending test, fiber orientation on the ruptured surfaces of the specimens was observed. The flexural strengths of the specimens cut at angles of 60, 30 and 0° were 80, 40 and 10% of that for the specimen cut at an angle of 90°. It was also found that the flexural strength of specimens cut from a rectangular panel cast from its center point depended on their original positions and orientation within the panel. Similar fiber orientation characteristics were found in the circular and rectangular panels.

scholarly journals Experimental and Numerical Investigation on Shear Retrofitting of RC Beams by Prefabricated UHPFRC Sheets

2016 ◽  
Vol 2 (5) ◽  
pp. 168-179
Author(s):  
Kian Aghani ◽  
Hassan Afshin
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fem Analysis ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Externally Bonded ◽  
High Performance Fiber ◽  
Bending Capacity

Different methods are used for retrofitting RC members. One of the new methods in this field is using externally bonded fiber-reinforced Concrete (FRC) sheets in order to increase RC member’s shear and flexural strength. In this study, applicability of ultra-high performance fiber-reinforced concrete sheets in shear and flexural retrofitting of RC beams was investigated. In total, eight RC beams (dimensions 10×20×150 cm) with two different bending capacity and lack of shear strength were used and were tested in 3-points bending test. Of these, four were control beams and four were retrofitted with laterally bonded UHPFRC sheets. Dimensions of the sheets used for retrofitting were (3×15×126 cm). Also FEM analysis was used to model the effect of The method. the results show that this method can be well used for retrofitting RC beams. In this method the way of connecting sheets to beam’s surfaces has a fundamental role in behavior of retrofitted beams.

scholarly journals Performance of Cracked Ultra-High-Performance Fiber-Reinforced Concrete Exposed to Dry-Wet Cycles of Chlorides

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Longlong Niu ◽  
Shiping Zhang
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
High Performance ◽  
Chloride Ion ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Self Healing ◽  
Fiber Reinforced ◽  
High Performance Fiber ◽  
Corrosion Of Steel

This paper presents an experimental study on the performance of cracked ultra-high-performance fiber-reinforced concrete (UHPC) exposed to dry-wet cycles of 3.5% NaCl solution under the temperature of 60°C. The results show that the wider the crack, the higher the corrosion degree of steel fibers embedded in UHPC, and the deeper the chloride ion diffusion on both sides of the crack. With the increase of dry-wet cycles, the flexural strength of precracked UHPC first decreases and then increases, and the lowest flexural strength was observed in 60 dry-wet cycles. Although self-healing is hard to cease the corrosion of steel fibers, it can relieve the corrosion of steel fibers and improve the flexural strength exposed to 100 dry-wet cycles.

A method for evaluating the local failure of ultra-high-performance short polyvinyl alcohol fiber-reinforced concrete panels subjected to a projectile impact

2018 ◽  
Vol 9 (3) ◽  
pp. 289-312 ◽  
Author(s):  
Hironori Ueno ◽  
Masuhiro Beppu ◽  
Hiroyoshi Ichino ◽  
Hiroyuki Musha ◽  
Shuichi Okamoto
Keyword(s):  
Reinforced Concrete ◽  
Polyvinyl Alcohol ◽  
Penetration Depth ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Local Failure ◽  
Fiber Reinforced ◽  
Concrete Panels ◽  
High Performance Fiber ◽  
The Impact

This study investigated local failure characteristics and failure limit thicknesses of an ultra-high-performance fiber-reinforced concrete panel reinforced with polyvinyl alcohol by conducting impact tests. In a series of tests, steel hemispherical projectiles with a mass of 46 g collided with ultra-high-performance fiber-reinforced concrete panels reinforced with polyvinyl alcohol. The ultra-high-performance fiber-reinforced concrete panels reinforced with polyvinyl alcohol with thicknesses in the range of 30–90 mm were tested at the impact velocities of 170–500 m/s. The experimental results revealed that the penetration depth or scabbing damage induced by the impact was significantly suppressed for the ultra-high-performance fiber-reinforced concrete panel reinforced with polyvinyl alcohol compared to that of a plain concrete panel. The experimental results demonstrated that local failure intensity for the panels was similar at equivalent impact energies, regardless of the combination of projectile mass and impact velocity. Based on the test results, we proposed a method for evaluating the penetration depth and scabbing limit thicknesses by the impact energy.

scholarly journals Flexural behaviour of ultra-high-performance fiber-reinforced concrete at high strain rates

2021 ◽  
Vol 63 (3) ◽  
pp. 40-45
Author(s):  
Tri Thuong Ngo ◽  
◽  
Van Hai Hoang ◽  
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Strain Rate ◽  
Volume Content ◽  
High Performance ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
High Performance Fiber ◽  
Flexural Resistance

In this study, the flexural resistance of ultra-high-performance fiber-reinforced concrete (UHPFRCs) containing different fiber volume content, under static and dynamic flexural loading was investigated. Thirty-six specimens of UHPFRCs, size 0.5x0.5x210 (mm), reinforced with 0.5%, and 1.5% volume of smooth steel fiber (d=0.2 mm, l=19 mm) were cast and tested by three-point bending test, under the static load (strain rate 1.67x10-5 s-1) and high acceleration load (strain rate up to 210 s-1). Experimental results show that the flexural strength of UHPFRCs increases significantly when the fiber reinforcement content increases. In addition, as the loading speed increases, the flexural resistance of the material also increases. The flexural strength of UHPFRC material reinforced with 0.5 and 1.5% of fiber volume content was 17.7 and 30.0 MPa at static loads, increased to 23.6 and 51.92 MPa at a loading rates of 110 s-1 and 28.86 and 61.04 MPa at loading rate of 210 s-1.

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