scholarly journals Evaluating Fresh and Hardened Properties of High-Strength Concrete Including Closed Steel Fibres

2021 ◽  
Vol 15 (1) ◽  
pp. 104-114
Author(s):  
Sarah Al-Qutaifi ◽  
Ali Bagheri
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Hardened Concrete ◽  
Steel Fibres ◽  
Concrete Mixtures ◽  
Concrete Permeability ◽  
Hardened Properties ◽  
Closed Steel

Background: The tensile strength of the plain concrete is weak. Thus, fibres are embedded in concrete to improve its ductility. However, pulling out steel fibres from concrete structures is one of the most encountered issues in the fiber-reinforced concrete, which hinders using their maximum capacities. Objectives: Thus, closed steel fibres (square shape) were incorporated into concrete mixes to evaluate their impacts against the pulling-out effects and assess the feasibility of applying Closed Steel Fibres (CSFs) on the fresh and hardened concrete properties. Hooked end and straight steel fibres were also investigated for comparison. Methods: The utilized steel fibres were incorporated with lengths of 20, 30, and 40 mm, and volume fractions of 0.25%, 0.50%, and 0.75%. Silica Fume (SF) was involved in the fibre-reinforced concrete mixtures at 7% of the cement weight. Results: Paper outcomes stated that the inclusion of steel fibres involved different impacts on the concrete compressive strength depending on the applied fibre geometries and content. Conclusion: CSFs exhibited better performance against the pulling-out effect from the surrounding concrete structure than those of hooked end and straight steel fibres. However, the addition of CSFs has increased the concrete permeability due to their poor space-filling capacity.

Mechanical Properties of Hybrid Basalt-Polyvinyl Alcohol (PVA) Fiber Reinforced Concrete

2017 ◽  
Vol 744 ◽  
pp. 3-7 ◽  
Author(s):  
Asif Jalal ◽  
Nasir Shafiq ◽  
Ehsan Nikbakht ◽  
Rabinder Kumar ◽  
Muhammad Zahid
Keyword(s):  
Reinforced Concrete ◽  
Volume Fraction ◽  
Peak Load ◽  
High Strength ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Maximum Deflection ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Pva Fiber

This study focuses on the study of the mechanical behavior of non-metallic hybrid Basalt-PVA fiber reinforced concrete. Total five mixes were investigated with one control plain concrete and four with fiber volume fraction of 0.3%, 0.6%, 0.9% and 1.2%. Basalt and PVA were used in same quantity. Fiber decreased workability, therefore superplasticizer was used to maintain workability constant. The increase in superplasticizer and fiber content decreased compression, split tensile and flexure strengths because of formation of big size pores. Whereas fiber enhanced the post peak load zone in the load-deflection curve. Fiber improved the bridging action by increasing energy absorption. Fiber vanished the brittle behavior of high strength concrete and increased first crack toughness, flexure toughness and also maximum deflection. 0.3% volume fraction of fiber was found to be optimum with the negligible decrease in compression, split tensile and flexure strength while caused the considerable increase in first crack toughness, flexure toughness, and maximum deflection.

Flexural Fatigue Behavior and Performance Characteristics of Polyacrylonitrile Fiber Reinforced Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 572-583
Author(s):  
Zong Cai Deng ◽  
Hong Liang Deng ◽  
Jian Hui Li ◽  
Guo Dong Liu
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Polyacrylonitrile Fiber ◽  
Hardened Concrete ◽  
Fiber Reinforced ◽  
Flexural Fatigue ◽  
Pan Fiber

This paper presents the results of an experimental investigation to determine the flexural fatigue strength and fatigue life of concrete beams reinforced with monofilament polyacrylonitrile fibers (PAN fiber for short). The performance of fresh concrete and the elastic and mechanical properties of hardened concrete are compared by samples with and without fibers. The toughness calculated according to both ASTM and JCI methods increased with the addition of fibers. The toughness indexes I5 was 3.8-4.2 times，I10 was 5.8—6.8 times that of the plain concrete. The equivalent strength was 0.63-0.87 MPa for PAN fiber reinforced concrete. When compared to plain concrete, the endurance limit of concrete beams only reinforced with PAN fiber is increased by 12 percent.

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
Keyword(s):  
Reinforced Concrete ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Cracking Behavior ◽  
Bending Tests ◽  
Depth Ratio ◽  
Residual Performance ◽  
Concrete Control

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.

scholarly journals Resistance of an Optimized Ultra-High Performance Fiber Reinforced Concrete to Projectile Impact

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 63
Author(s):  
Anna L. Mina ◽  
Michael F. Petrou ◽  
Konstantinos G. Trezos
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Depth Of Penetration ◽  
Projectile Impact ◽  
High Performance Fiber

The scope of this paper is to investigate the performance of ultra-high performance fiber reinforced concrete (UHPFRC) concrete slabs, under projectile impact. Mixture performance under impact loading was examined using bullets with 7.62 mm diameter and initial velocity 800 m/s. The UHPFRC, used in this study, consists of a combination of steel fibers of two lengths: 6 mm and 13 mm with the same diameter of 0.16 mm. Six composition mixtures were tested, four UHPFRC, one ultra-high performance concrete (UHPC), without steel fibers, and high strength concrete (HSC). Slabs with thicknesses of 15, 30, 50, and 70 mm were produced and subjected to real shotgun fire in the field. Penetration depth, material volume loss, and crater diameter were measured and analyzed. The test results show that the mixture with a combination of 3% 6 mm and 3% of 13 mm length of steel fibers exhibited the best resistance to projectile impact and only the slabs with 15 mm thickness had perforation. Empirical models that predict the depth of penetration were compared with the experimental results. This material can be used as an overlay to buildings or to construct small precast structures.

scholarly journals THE INFLUENCE OF TENSILE RESISTANCE OF ULTRA HIGH STRENGTH FIBER REINFORCED CONCRETE ON FLEXURAL FAILURE

2008 ◽  
Vol 64 (3) ◽  
pp. 435-448
Author(s):  
Tetsuo KAWAGUCHI ◽  
Makoto KATAGIRI ◽  
Kazuyoshi SHIRAI ◽  
Junichiro NIWA
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Flexural Failure ◽  
High Strength Fiber

Shear Behavior of RC Beams Using Ultra High Strength Fiber Reinforced Concrete Precast Formworks

2012 ◽  
Vol 18 (31) ◽  
pp. 222-229
Author(s):  
Chunyakom Sivaleepunth ◽  
Toshimichi Ichinomiya ◽  
Shinichi Yamanobe ◽  
Tetsuya Kono ◽  
Naoki Sogabe ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
Shear Behavior ◽  
Fiber Reinforced Concrete ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
High Strength Fiber

scholarly journals Ductility and flexure of lightweight expanded clay basalt fiber reinforced concrete slab

2021 ◽  
Vol 17 (1) ◽  
pp. 74-81
Author(s):  
Vera V. Galishnikova ◽  
Alireza Heidari ◽  
Paschal C. Chiadighikaobi ◽  
Adegoke Adedapo Muritala ◽  
Dafe Aniekan Emiri
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Lightweight Aggregate Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Chopped Basalt Fiber

Relevance. The load on a reinforced concrete slab with high strength lightweight aggregate concrete leads to increased brittleness and contributes to large deflection or flexure of slabs. The addition of fibers to the concrete mix can improve its mechanical properties including flexure, deformation, toughness, ductility, and cracks. The aims of this work are to investigate the flexure and ductility of lightweight expanded clay concrete slabs reinforced with basalt fiber polymers, and to check the effects of basalt fiber mesh on the ductility and flexure. Methods. The ductility and flexural/deflection tests were done on nine engineered cementitious composite (expanded clay concrete) slabs with dimensions length 1500 mm, width 500 mm, thickness 65 mm. These nine slabs are divided in three reinforcement methods types: three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm (first slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed chopped basalt fiber plus basalt fiber polymer (mesh) of cells 2525 mm (second slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed basalt fiber of length 20 mm, diameter 15 m (third slab type). The results obtained showed physical deflection of the three types of slab with cracks. The maximum flexural load for first slab type is 16.2 KN with 8,075 mm deflection, second slab type is 24.7 KN with 17,26 mm deflection and third slab type 3 is 32 KN with 15,29 mm deflection. The ductility of the concrete slab improved with the addition of dispersed chopped basalt fiber and basalt mesh.

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