scholarly journals Effect of the Notch-to-Depth Ratio on the Post-Cracking Behavior of Steel-Fiber-Reinforced Concrete

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 445
Author(s):  
José Valdez Aguilar ◽  
César A. Juárez-Alvarado ◽  
José M. Mendoza-Rangel ◽  
Bernardo T. Terán-Torres

Concrete barely possesses tensile strength, and it is susceptible to cracking, which leads to a reduction of its service life. Consequently, it is significant to find a complementary material that helps alleviate these drawbacks. The aim of this research was to determine analytically and experimentally the effect of the addition of the steel fibers on the performance of the post-cracking stage on fiber-reinforced concrete, by studying four notch-to-depth ratios of 0, 0.08, 0.16, and 0.33. This was evaluated through 72 bending tests, using plain concrete (control) and fiber-reinforced concrete with volume fibers of 0.25% and 0.50%. Results showed that the specimens with a notch-to-depth ratio up to 0.33 are capable of attaining a hardening behavior. The study concludes that the increase in the dosage leads to an improvement in the residual performance, even though an increase in the notch-to-depth ratio has also occurred.

2019 ◽  
Vol 10 (1) ◽  
pp. 241
Author(s):  
Wenjin Yao ◽  
Weiwei Sun ◽  
Ze Shi ◽  
Bingcheng Chen ◽  
Le Chen ◽  
...  

This paper experimentally investigates the blast-resistant characteristics of hybrid fiber-reinforced concrete (HFRC) panels by contact detonation tests. The control specimen of plain concrete, polypropylene (PP), polyvinyl alcohol (PVA) and steel fiber-reinforced concrete were prepared and tested for characterization in contrast with PP-Steel HFRC and PVA-Steel HFRC. The sequent contact detonation tests were conducted with panel damage recorded and measured. Damaged HFRC panels were further comparatively analyzed whereby the blast-resistance performance was quantitively assessed via damage coefficient and blast-resistant coefficient. For both PP-Steel and PVA-Steel HFRC, the best blast-resistant performance was achieved at around 1.5% steel + 0.5% PP-fiber hybrid. Finally, the fiber-hybrid effect index was introduced to evaluate the hybrid effect on the explosion-resistance performance of HFRC panels. It revealed that neither PP-fiber or PVA-fiber provide positive hybrid effect on blast-resistant improvement of HFRC panels.


Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 93 ◽  
Author(s):  
Boglárka Bokor ◽  
Máté Tóth ◽  
Akanshu Sharma

Increased loading rates on fasteners may be caused by high ground accelerations as a consequence of e.g., nuclear explosions, earthquakes or car collisions. It was concluded by Hoehler et al. (2006) that fasteners under rapid loading rates show an increased ultimate resistance in the concrete dominant failure modes or the ultimate resistance is at least as large as under quasi-static loading. Due to the increased demand on using fasteners in steel fiber reinforced concrete (SFRC), it is intended to show how the ultimate concrete cone capacity of fasteners changes under higher than quasi-static loading rate in normal plain concrete (PC) and in SFRC. This paper presents the results of an extensive experimental program carried out on single fasteners loaded in tension in normal plain concrete and in SFRC. The test series were conducted using a servo-hydraulic loading cylinder. The tests were performed in displacement control with a programmed ramp speed of 1, 100, 1000, and 3500 mm/min. This corresponded to calculated initial loading rates ranging between 0.4 and 1600 kN/s. The results of the tension tests clearly show that the rate-dependent behavior of fasteners in SFRC with 30 and 50 kg/m3 hooked-end-type fibers fits well to the previously reported rate-dependent concrete cone behavior in normal plain concrete. Additionally, a positive influence of the fibers on the concrete cone capacity is clearly visible.


2008 ◽  
Vol 400-402 ◽  
pp. 391-394
Author(s):  
Ming Hui Wei ◽  
Yi Ping Liu ◽  
Li Qun Tang ◽  
Xiao Qing Huang

Flexure behaviors of plain concrete (PC), steel fiber reinforced concrete (SFRC), polymer modified concrete (PMC), steel fiber reinforced and polymer modified concrete (SFRPMC) and hybrid fiber reinforced concrete (HFRC) with steel fiber and polymer fiber are studied in this paper, flexure tests were carried out and flexure strengths of the five different materials with different mixture ratios were measured and compared. Flexure ductility of PC, PMC, SFRC, and SFRPMC were calculated and compared. In addition, considering performance and cost estimation comprehensively, HFRC is recommended, preliminary tests show that HFRC may be one of the potential materials for bridge pavement.


2018 ◽  
Vol 768 ◽  
pp. 326-330
Author(s):  
Bo Chen ◽  
Li Ping Guo ◽  
Wei Sun ◽  
Cong Ding

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.


2009 ◽  
Vol 79-82 ◽  
pp. 1771-1774
Author(s):  
Min Bai ◽  
Di Tao Niu ◽  
Xiong Wu

In recent years, the concrete material subject to chloride corrosion which impacts greatly on the durability of the building project in the marine or coastal environment has been reported repeatedly. With the problems becoming more and more serious, much attention has been paid on it gradually. To improve the durability of the concrete structure in the marine environment, the author tried to add the different content of steel fiber into the concrete and research the permeability of the concrete in the chloride environment. Four different volumes of steel fiber were selected to prepare the concrete. The dates of the proportion are as follows, 1)0.5%; 2)1%; 3)1.5%; 4)2%. Leave the steel fiber reinforced concrete and plain concrete to soak in the sodium chloride solution which mass percent is 3.5%. The soak time is 30, 60, 90,120, 180 days separately. Among this, the test items include the penetration depth of chloride, the chloride ion content and the splitting strength after soaking period. As a result of the test, it is demonstrated that chloride penetration-resistant of steel fiber reinforced concrete is better than plain concrete. The best performance is obtained when the content of steel fiber is 1.5%. The results will be very useful to the concrete professional dealing with chloride-ion penetration. In conclusion, it is convinced that the application of this result in marine engineering will bring well economic and social environmental benefits for the society.


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