Shear behavior of reinforced ultra light weight concrete beams with shear reinforcement

2021 ◽  
pp. 195-200
Author(s):  
K. Fukuzawa ◽  
M. Mitsui ◽  
S. Soh
Keyword(s):  
Concrete Beams ◽  
Shear Behavior ◽  
Light Weight ◽  
Shear Reinforcement ◽  
Light Weight Concrete

Influence of synthetic fibers on the shear behavior of lightweight concrete beams

2017 ◽  
Vol 20 (11) ◽  
pp. 1671-1683 ◽  
Author(s):  
Ayman Ababneh ◽  
Rajai Al-Rousan ◽  
Mohammad Alhassan ◽  
Mohammed Alqadami
Keyword(s):  
Shear Strength ◽  
Lightweight Concrete ◽  
Concrete Beams ◽  
Shear Behavior ◽  
Fiber Content ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Ultimate Shear Strength ◽  
Synthetic Fibers

Incorporating discontinuous structural synthetic fibers in general enhances the performance of concrete and increases its durability by minimizing its potential to cracking and providing crack arresting mechanism. Synthetic fibers are non-corrosive, alkali resistant, simple to apply, and added in small quantities due to their low density; thus, a substantial number of uniformly distributed fibers are added. In this research, an experimental program was undertaken to investigate the shear behavior of lightweight concrete beams containing discontinuous structural synthetic fibers. The studied parameters include fiber content and shear reinforcement. The tests were conducted under four-point loading in a simply supported span of 0.85 m. The beams were divided into three groups based on shear reinforcement. Group 1 was designed without shear reinforcement, Group 2 with closed vertical stirrups placed at d/4 spacing (where d is the effective depth), and Group 3 with closed vertical stirrups placed at d/2 spacing. Each group contains four identical specimens except in terms of the fiber content: 0, 3, 5, and 7 kg/m3 equivalent to fiber volume fractions of 0%, 0.33%, 0.55%, and 0.77%, respectively. The experimental results showed that the discontinuous structural synthetic fibers improve the ultimate shear strength, ductility, stiffness, and toughness of lightweight concrete beams significantly. Therefore, design codes are encouraged to consider their contribution to shear strength and revise the maximum stirrups spacing when discontinuous structural synthetic fibers are used. The results also showed that addition of discontinuous structural synthetic fibers reduces the crack width of lightweight reinforced concrete beams. The effectiveness of the discontinuous structural synthetic fibers decreases as the stirrups spacing decreases.

scholarly journals Shear behavior of steel or basalt fiber reinforced concrete beams without stirrup reinforcement

2017 ◽  
Vol 4 (20) ◽  
pp. 391-404
Author(s):  
Julita Krassowska ◽  
Marta Kosior-Kazberuk
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Basalt Fiber ◽  
Shear Behavior ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement ◽  
Fiber Reinforced

The paper presents the results of a comprehensive investigation aimed at studying the shear behavior of basalt or steel fiber-reinforced concrete (BFRC or SFRC) beams, as well as analyzing the possibility of using basalt or steel fibers as a minimum shear reinforcement. Two-span reinforced concrete beams with the cross-section of 8×16 cm and length of 200 cm and diversified spacing of stirrups were tested. Steel stirrups or alternatively steel or basalt fibers were used as a shear reinforcement. Steel fiber content was 80 and 120 kg/m3and basalt fiber content was 2.5 and 5.0 kg/m3. The shear behavior and/or bending capacity of SFRC and BFRC beams were studied. The result indicated that fibers can be safely used as a minimum shear reinforcement.

Effective fiber type investigation on the shear behavior of ultrahigh-performance fiber-reinforced concrete beams

2019 ◽  
Vol 22 (7) ◽  
pp. 1591-1605 ◽  
Author(s):  
Altuğ Yavaş ◽  
Umut Hasgul ◽  
Kaan Turker ◽  
Tamer Birol
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Fiber Type ◽  
Shear Behavior ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Fiber Types ◽  
Shear Reinforcement ◽  
Fiber Reinforced ◽  
Straight Fiber

In this study, the effects of different fiber types on shear behavior (cracking pattern, shear cracking strength, ultimate shear strength, and post-cracking deformability) of ultrahigh-performance fiber-reinforced concrete beams were investigated experimentally. For this purpose, 15 ultrahigh-performance fiber-reinforced concrete beams including different steel fiber types (two straight, two hooked, and one double hooked) with three volume fractions (0.5%, 1.0%, and 1.5%) were casted without shear reinforcement and tested under four-point loading until the failure. In addition to the experimental program, three existing numerical models proposed for the shear capacity of fiber-reinforced concrete beams were investigated to show the applicability of these models to the ultrahigh-performance fiber-reinforced concrete beams. The experimental results demonstrated that the straight fiber of 13 mm is the most effective fiber type in terms of the considered parameters. However, the addition of 13-mm straight fiber with 1.5% by volume into the ultrahigh-performance fiber-reinforced concrete beam changed the failure mode from the shear to flexure without shear reinforcement.

scholarly journals The Effect of Steel and Basalt Fibers on the Shear Behavior of Double-Span Fiber Reinforced Concrete Beams

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6090
Author(s):  
Julita Krassowska ◽  
Marta Kosior-Kazberuk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Design Codes ◽  
Shear Reinforcement ◽  
Fiber Reinforced ◽  
Basalt Fibers

This study investigates the effects of adding different types of fibers to concrete mixes on the shear behavior of double-span fiber-reinforced concrete beams with or without shear reinforcement. As a part of the experimental study, a total of twenty-seven natural-scale double-span beams were tested. The beams, made of concrete with steel or basalt fiber, with fiber dosages of 78.5 and 5 kg/m3, were tested under shear force. The three tested series consisted of three beams with dimensions of 120 × 300 × 4150 mm, with various numbers of stirrups and contents of fiber reinforcement. During the tests, the shear capacity of the elements was determined. The values of support reactions, deflection in the middle of the span of both beam spans, deformations on the surface of the concrete member in the middle of the span in the compressive and tensile zone, and cracking (crack development and crack width) were also measured. The beams were tested using a digital image correlation (DIC) technique. Test results show that shear capacity increases in beams made of concrete with steel (1.87) or basalt fibers (1.23). Moreover, the failure mode changes from shear (brittle) to flexure-shear (less brittle). The experimental shear capacity of beams was compared with the theoretical values predicted by different design codes, i.e., fib Model Code 2010 and RILEM TC 162-TDF 2003. The results show that all the design codes underestimate the contribution of fiber-reinforced concrete beams to shear resistance and greatly overestimate the contribution of shear reinforcement.

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