scholarly journals Complex Permittivity Measurements of Steel Fiber-Reinforced Cementitious Composites Using a Free-Space Reflection Method with a Focused Beam Lens Horn Antenna

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7789
Author(s):  
Kyeongyong Cho ◽  
Sunghui Jo ◽  
Yeong-Hoon Noh ◽  
Namkon Lee ◽  
Sungwook Kim ◽  
...  
Keyword(s):  
Complex Permittivity ◽  
Free Space ◽  
Steel Fiber ◽  
Horn Antenna ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Electromagnetic Properties ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Focused Beam

To measure the electromagnetic properties of steel fiber-reinforced concrete (SFRC) in the X-band, 1-port measurements were performed using a lens horn antenna in a free-space measurement system. Free-space 1-port calibration with translations of the position of the reflector regarding the characteristics of the focused beam lens horn antenna was applied. The intrinsic impedance and complex permittivity of the SFRC were obtained from the measured reflection characteristics. The steel fiber content increased and the electromagnetic properties of the SFRC gradually changed from a dielectric to a conductor, even in very low frequencies compared to the plasma frequencies of general metal, which are optical frequencies. This is considered to be the plasmon effect of the metallic structure formed by the steel fiber. This result is applicable for analyses of the electromagnetic phenomenon of large structures with fiber content.

Penetration Resistance Research of Fiber Reinforced RPC

2014 ◽  
Vol 1055 ◽  
pp. 23-26
Author(s):  
Can Xu
Keyword(s):  
Reinforced Concrete ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Penetration Resistance ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Quartz Powder ◽  
Steel Fiber Reinforced Concrete

In the original to remove steel and steel fiber reinforced concrete coarse aggregate in quartz powder and a small amount of activator, can boost steel fiber content, and its application in construction makes it more convenient, but how the penetration resistance works is not particularly clear. Through the penetration resistance experiment, found that when joined the SF and BF, RPC can still keep complete even after three times by penetration ,indicating the good performance of penetration resistance.

Bending Tests of Full-Scale Steel Fiber-Reinforced Concrete Segments of Shield Tunnel

2018 ◽  
Vol 768 ◽  
pp. 326-330
Author(s):  
Bo Chen ◽  
Li Ping Guo ◽  
Wei Sun ◽  
Cong Ding
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Peak Load ◽  
Full Scale ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Shield Tunnel ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Bending Tests

To evaluate the bending performance of a steel fiber-reinforced concrete shield segment, bending testing was conducted on prism specimens and full-scale segments with 30 kg/m3and 40 kg/m3steel fiber. The results show that, with increasing fiber content, the ultimate and equivalent flexural strengths increase, while the flexural toughness of the prism concrete specimen increases by approximately 15%. With increasing fiber content, the flexural capacity of the shield tunnel segment increases, the peak load increases by 24%, the crack number increases, and the average crack width decreases. During bending tests, the steel fiber-reinforced concrete segment shows remarkable characteristics of strain hardening and multiple cracking. The embedded parts reduce the cross-sectional area and cause stress concentration in the mid-span; therefore, the main crack form in this region.

scholarly journals Experimental Investigation on Mechanical Behavior of Anchor and Shotcrete Support System Under Axial Pull-out Action

2021 ◽  
Author(s):  
Xiliang Liu ◽  
Feiyue Sun ◽  
Fuli Kong ◽  
Jiaqi GUO
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Behavior ◽  
Support System ◽  
Steel Fiber ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Pull Out ◽  
Failure Properties

Abstract Based on axial pull-out performance tests of anchor and shotcrete support system with three types of plates and two kinds of shotcretes (plain and steel fiber reinforced concrete) conducted by use of the multi-functional testing system. The mechanical behavior of the anchor and shotcrete support system with the different plate and shotcrete such as the pull-out performance of support system, deformation and failure properties of shotcrete was studied and analyzed. Experimental results showed that the relationship curves between elongation and drawing force has three stages, which are elastic, yielding and strengthening. Different plate types have obvious influence on the tensile stiffness during the elastic stage. The steel fiber reinforced concrete spray layer can improve the yield strength of rockbolt under the coupling effect by the support system. The strain at the interface between the initial shotcrete layer and surrounding rock mass is greater than that of the external surface of the resprayed shotcrete layer, though they are equal far away from the rockbolt hole. The shotcrete strain values of steel fiber reinforced concrete is lower than that of plain concrete, and the shotcrete strain values decreases with the improvement of steel fiber content. For shotcrete strain values on the same position, the higher they are the steel fiber content, the lower their strain will be. The failure of plain shotcrete usually begins around of rockbolt hole, when the interfacial stress between the initial shotcrete layer and surround rock is higher than that in the initial shotcrete layer and resprayed shotcrete layer. The steel fiber can effectively improves the toughness, anti-cracking performance and prevent fracture of shotcrete from failure properties.

scholarly journals Exploration of Characteristics of Steel Fiber Reinforced Concrete and Its Influence on Regular Concrete

2020 ◽  
Vol 9 (2) ◽  
pp. 209-212
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Plain Concrete ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Synthetic Fibers

Concrete is the most widely used product in the construction sector mainly because of its properties and its capability to be moulded to any size. Plain concrete has low tensile strength and forms internal micro cracks. It has been proven that with the addition of natural fibers and synthetic fibers in concrete, it helps in the durability and functionality of structure. The steel fibers are added to the concrete in very low volume doses and it has been effective in decreasing the plastic shrinkage in cracking and also acting as a crack arrestor. In this journal, experimental analysis on steel fiber reinforced concrete is done on M30 and M50 mix with 0.5%, 1%, 1.5% and 2% volume fraction of steel fiber content and is compared with samples of 0% steel fiber content and these samples are investigated on their compressive, split tensile and flexural strengths.

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