scholarly journals Prediction of Fiber Reinforced Concrete Strength Properties by Micromechanics Method

2019 ◽  
Vol 5 (1) ◽  
pp. 200 ◽  
Author(s):  
Shriganesh Shantikumar Kadam ◽  
V. V. Karjinni ◽  
C. S. Jarali

High strength steel fiber reinforced concrete (HSSFRC) was prepared with the help of steel fiber. 0.5%, 1.0%, and 1.5% steel fiber by volume of concrete specimen was used in concrete for present investigation. Compressive strength test and flexural strength test were conducted on cubical and prismatic specimens respectively.The main objective of the research work is to validate the experimental out comes by a numerical technique such as micromechanics approach. A high strength steel fiber reinforced concrete whose compressive strength is greater than 60 N/mm2 was prepared and tested on concrete testing machine. Flexural strength test was conducted on universal testing machine to evaluate the bending properties of concrete. It was observed that with increase in the percentage of steel fiber volume the compressive strength and flexural strength also increases. However the workability of concrete declines and concrete is no longer in working condition. Micromechanics technique helps to predict the strength properties which save time required for casting and such technique was found to be beneficial.

2021 ◽  
Vol 16 (4) ◽  
pp. 169-176
Author(s):  
Xiaohu Luo

In order to improve the application effect of steel fiber reinforced concrete (SFRC) in road bridge construction, the mechanical properties of SFRC with different fiber content were analyzed. The SFRC specimens with 0%, 0.5%, 1%, 1.5% and 2% fiber content were designed, and the mechanical properties were tested. The results showed that the compressive strength first increased and then decreased with the increase of fiber content, and the maximum compressive strength of SFRC1.5 reached 40.86 MPa, increasing by 7.19%; the increase amplitude of tensile strength of SFRC1.5 was 73.04%, which was the most obvious; the flexural strength of SFRC increased with the increase of fiber content, and the flexural strength of SFRC2 was 9.78 MPa, increasing by 94.43%. It is concluded from the experimental results of a case study that SFRC1.5 presents the optimal overall mechanical properties and is more suitable for road bridge construction.


This paper enumerates the experimental study on workability and strength properties of concrete containing different dosage of polypropylene fiber from 0.1% to 0.6% and 1.0% to 3.5% of steel fiber. Water - binder ratio, fiber type and fiber dosage influence on flow behaviour, compressive strength, flexural strength and brittleness ratio were analysed. Experimental results were substantiated by linear regression analysis considering 95% confidence level. Reference mixes with 0.34 and 0.36 water- binder were prepared for results comparison with polypropylene and steel fiber reinforced concretes. Test results showed comparatively higher workability reduction in polypropylene fiber reinforced concrete. Compressive strength test results of fiber reinforced concrete indicted an optimum fiber content of 0.30% of polypropylene fiber and 2.50% of steel fiber. Steel fiber reinforced concrete displayed continuous increase in flexural strength with 44.46% average increase. Brittleness ratio, which was the ratio of flexural strength and compressive strength showed maximum value of 0.24 for concrete with 3.5 % steel fiber and 0.36 w/B ratio. Linear regression analysis revealed good correlation of flow properties with w/B ratio irrespective of fiber type. Though the compressive strength had low correlation with fiber type and w/B ratio, steel fiber reinforced concrete indicated up to 0.987 coefficient of determination with flexural strength.


2011 ◽  
Vol 71-78 ◽  
pp. 1083-1089
Author(s):  
Zhang Luo

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%.


Author(s):  
Payal Sachdeva ◽  
A.B. Danie Roy ◽  
Naveen Kwatra

Headed bars (HB) with different head shapes (Square, Circular, and Rectangular) and bar diameters (db: 16, 20, and 25 mm) embedded in steel fiber reinforced concrete have been subjected to pull-out test. The influence of head shapes, concrete compressive strength (M20 and M40), db, and steel fibers (0, 0.5, 1, and 1.5%) on the anchorage capacity of HB have been evaluated. Numerical model for improving the anchorage capacity of HB has also been proposed. Results have revealed that the anchorage capacity of HB increases with the increase in concrete compressive strength, db, and steel fibers, which have been validated by non-linear regression analysis using dummy variables. Two failure modes namely, steel and concrete-blowout have been observed and the prevailing mode of failure is steel failure. Based on load-deflection curves and derived descriptive equations, it is observed that the circular HB has displayed the highest peak load.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5202
Author(s):  
Mohammad Iqbal Khan ◽  
Wasim Abbass ◽  
Mohammad Alrubaidi ◽  
Fahad K. Alqahtani

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.


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