Experimental Study on Rate-Dependent of the Bending Tensile Properties for Steel Fiber Reinforced Concrete

2011 ◽  
Vol 71-78 ◽  
pp. 1083-1089
Author(s):  
Zhang Luo
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Strain Rate ◽  
Tensile Properties ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Test Machine ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Rate Dependent

Extensive experimental research has been done on rate-dependent properties normal concrete, but very little on the tensile properties of steel fiber reinforced concrete (SFRC). In this article, based on a high-speed Instron servo-controlled hydraulic materials test machine is adopted to investigate the strain rate-dependent properties of bending tensile properties for SFRC. The scheme of experiment, the works of specimens fabricating and the processes of both loading and measuring were introduced. A total of 30 beam specimens are tested. The steel fiber content is varied: 0%, 1.0%, 2.0%, 3.0% and 4.0% by volume. The experimental results were analyzed. The emphasis is put on the study of the flexural strength changes of SFRC under different strain rates. It is discovered that, with the improvement of the strain rate, increasing strength of SFRC is very obvious. While the strain rate increases from 1.4×10-4s-1 to 0.53×10-4s-1, the flexural strength increasing around 30%.

scholarly journals Fasteners in Steel Fiber Reinforced Concrete Subjected to Increased Loading Rates

Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 93 ◽  
Author(s):  
Boglárka Bokor ◽  
Máté Tóth ◽  
Akanshu Sharma
Keyword(s):  
Reinforced Concrete ◽  
Static Loading ◽  
Steel Fiber ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Loading Rates ◽  
Rate Dependent ◽  
Ultimate Resistance

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.

scholarly journals Optimization of the Fine to Coarse Aggregate Ratio for the Workability and Mechanical Properties of High Strength Steel Fiber Reinforced Concretes

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5202
Author(s):  
Mohammad Iqbal Khan ◽  
Wasim Abbass ◽  
Mohammad Alrubaidi ◽  
Fahad K. Alqahtani
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fresh State

High-strength concrete is used to provide quality control for concrete structures, yet it has the drawback of brittleness. The inclusion of fibers improves the ductility of concrete but negatively affects the fresh properties of fiber-reinforced concrete. The effects of different fine to coarse aggregate ratios on the fresh and hardened properties of steel fiber reinforced concrete were investigated in this study. Mixtures were prepared with various fine to coarse aggregate (FA/CA) ratios incorporating 1% steel fiber content (by volume) at constant water to cement ratio. The workability, unit weight, and temperature of the concrete in the fresh state, and the mechanical properties of steel-fiber-reinforced concrete (SFRC) were investigated. The inclusion of fiber in concrete influenced the mobility of concrete in the fresh state by acting as a barrier to the movement of coarse aggregate. It was observed that the concrete with an FA/CA ratio above 0.8 showed better flowability in the fresh state, whilst an above 0.9 FA/CA ratio requires excessive superplasticizer to maintain the flowability of the mixtures. The compressive and flexural strength of SFRC increased with an increase in the FA/CA ratio by around 10% and 28%, respectively. Experimental values of compressive strength and flexural strength showed good agreement, however, modulus of elasticity demonstrated slightly higher values. The experimentally obtained measurements of the mechanical properties of SFRC conformed reasonably well with the available existing prediction equations, and further enabled establishing predictive isoresponse interactive equations within the scope of the investigation domain.

scholarly journals Characteristics of Steel Fiber Reinforced Concrete With Recycled Coarse Aggregate

2018 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Mustaqqim Abdul Rahim ◽  
Omi Yanti Pohan ◽  
Mohd Badrul Hisyam Ab Manaf ◽  
Ahmad Nur Aizat Ahmad ◽  
Shahiron Shahidan ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Compression Strength ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Control Sample ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete

Steel is one of the fibers used in fiber reinforced concrete technology. Steel fibers in concrete help to improve flexural  strength and  crack  resistance. Today,  there  are  critical  shortages of  natural  resources. In  this  research,  waste concrete is being used to produce recycled aggregate. The Recycled Coarse Aggregate (RCA) is partially replaced with the natural coarse aggregate (NCA) in concrete to analyze the mechanical properties of steel fiber reinforced concrete (SFRC). Several tests were conducted, such as compression and flexural tests. Five batches (A, B, C, D and E) of concrete cube and prism samples with different proportions of RCA (0%, 25%, 50%, 75% & 100%) and 1.5% volume fraction of steel fiber were tested, together with one control sample which used 100% NCA and 0% volume fraction of steel fiber. As a result, the control sample achieved 27.32 MPa in compression strength and 0.90 MPa for flexural strength while batch A managed to achieve 48.60 MPa and 1.10  MPa respectively. The cube and prism samples of all batches (A, B, C, D, E) showed decreasing compressive and flexural strength with increasing proportion of RCA in the concrete. Four samples fully achieved more than 20 MPa of compression strength and optimum flexural strength.

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