Shear strength of reinforced concrete beams with a fiber concrete matrix

2006 ◽  
Vol 33 (6) ◽  
pp. 726-734 ◽  
Author(s):  
Fariborz Majdzadeh ◽  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforcement ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Fiber Volume

The purpose of this study was to investigate the influence of fiber reinforcement on the shear capacity of reinforced concrete (RC) beams. Both steel and synthetic fibers at variable volume fractions were investigated. Two series of tests were performed: structural tests, where RC beams were tested to failure under an applied four-point load; and materials tests, where companion fiber-reinforced concrete (FRC) prisms were tested under direct shear to obtain material properties such as shear strength and shear toughness. FRC test results indicated an almost linear increase in the shear strength of concrete with an increase in the fiber volume fraction. Fiber reinforcement enhanced the shear load capacity and shear deformation capacity of RC beams, but 1% fiber volume fraction was seen as optimal; no benefits were noted when the fiber volume fraction was increased beyond 1%. Finally, an equation is proposed to predict the shear capacity of RC beams.Key words: shear strength, fiber-reinforced concrete, RC beam, stirrups, energy absorption capacity, steel fiber, synthetic fiber.

scholarly journals Using Steel Fiber-Reinforced Concrete Precast Panels for Strengthening in Shear of Beams: An Experimental and Analytical Investigation

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Pitcha Jongvivatsakul ◽  
Linh V. H. Bui ◽  
Theethawachr Koyekaewphring ◽  
Atichon Kunawisarut ◽  
Narawit Hemstapat ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Simple Formulation

In this paper, the performances of reinforced concrete (RC) beams strengthened in shear with steel fiber-reinforced concrete (SFRC) panels are investigated through experiment, analytical computation, and numerical analysis. An experimental program of RC beams strengthened by using SFRC panels, which were attached to both sides of the beams, is carried out to investigate the effects of fiber volume fraction, connection type, and number and diameter of bolts on the structural responses of the retrofitted beams. The current shear resisting model is also employed to discuss the test data considering shear contribution of SFRC panels. The experimental results indicate that the shear effectiveness of the beams strengthened by using SFRC panels is significantly improved. A three-dimensional (3D) nonlinear finite element (FE) analysis adopting ABAQUS is also conducted to simulate the beams strengthened in shear with SFRC panels. The investigation reveals the good agreement between the experimental and analytical results in terms of the mechanical behaviors. To complement the analytical study, a parametric study is performed to further evaluate the influences of panel thickness, compressive strength of SFRC, and bolt pattern on the performances of the beams. Based on the numerical and experimental analysis, a shear resisting model incorporating the simple formulation of average tensile strength perpendicular to the diagonal crack of the strengthened SFRC panels is proposed with the acceptable accuracy for predicting the shear contribution of the SFRC system under various effects.

Flexural Fatigue Damage Evolution for Partially High Percentage Fiber Reinforced Concrete

2006 ◽  
Vol 324-325 ◽  
pp. 827-830
Author(s):  
Cheng Yi ◽  
Shi Zhao Shen ◽  
He Ping Xie ◽  
Chang Jun Wang
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Damage ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Flexural Fatigue

Partially High Percentage Fiber Reinforced Concrete (PHPFRC) is a kind of cement composite in which fibers are concentrated with high volume fraction in the tension region of the component under bending. Therefore, PHPFRC possesses much higher load bearing capacity, rigidity, fatigue and fracture properties than conventional steel fiber reinforced concrete (SFRC) while its cost is similar to that of SFRC. In this paper, the fatigue test of PHPFRC is carried out to gain its flexural fatigue damage evolution rule. It is found from the test that, PHPFRC have long post-crack fatigue life and its fatigue damage is tough damage. Based on the continuum damage mechanics and fatigue behavior of the specimens, a fatigue damage variable D for PHPFRC is defined and the elementary form of damage evolution function is determined. For the specimens in which average fiber volume fraction are 1.2% and local fiber volume fraction are 10%, the function parameters and the damage threshold value are given according to the test results.

Properties of Polymeric Fiber-Reinforced Concrete

1996 ◽  
Vol 1532 (1) ◽  
pp. 27-35
Author(s):  
P. Balaguru ◽  
Anil Khajuria
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Strength ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Modulus Of Rupture ◽  
Unit Weight ◽  
Fiber Reinforced ◽  
Fiber Volume

The mechanical properties of lightweight and normal concrete containing nylon polymeric fibers are presented. Fiber reinforced concrete made with nylon fibers was evaluated. The 19-mm-long fibers were in single filament form. The control concrete was designed for a compressive strength of 20 MPa. The primary independent variable was fiber volume fraction. The response variables were air content, unit weight of fresh concrete, compressive strength, modulus of rupture (flexural strength) and toughness, splitting tensile strength, and impact strength. The addition of fibers decreased the slump values. The decrease was negligible at fiber contents of 0.45 and 0.6 kg/m3. The fibers distributed well in the matrix. Fibers could be directly added in the mixer. The effect fibers had on unit weight of concrete is negligible. Addition of fibers up to 2.4 kg/m3 did not change the compressive, flexural, and splitting tensile strengths appreciably. Impact strength and flexural toughness increased consistently with the increase of fiber volume fraction.

Shrinkage Performance of Adherence of New Steel Fiber-Reinforced Concrete to Old Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 3569-3574
Author(s):  
Hong Qiang Cheng ◽  
Dan Ying Gao
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Fiber Volume ◽  
Shrinkage Force ◽  
The Difference

Shrinkage experiments were done to determine the influence of the volume fraction of steel fiber-reinforcement on the bonding behavior between new concrete and old concrete. The mechanics of the model of restricted shrinkage upon the adherence of new steel fiber reinforced concrete to old concrete are described. The results demonstrate that the difference of shrinkage between the new and the old concrete can been reduced by adding steel fiber to the new concrete. The decrease of shrinkage difference reduces the shrinkage force at the adhesive interface, which improves the adhesion of new concrete to old concrete and the magnitude of the decrease of shrinkage difference is correlated to the steel fiber volume fraction.

Improvement of Impact Resistance of Synthetic Macro-Fiber Reinfored Concrete

2014 ◽  
Vol 578-579 ◽  
pp. 501-504
Author(s):  
Guo Chao Wang ◽  
Bo Xin Wang
Keyword(s):  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
The Impact

The incorporation of a small amount of steel fibers or fine polypropylene fibers in concrete can increase its impact resistance. But steel fiber has the problems of corrosion, high cost and high mess. The effect of fine polypropylene fibers in inhibiting the impact crack is not effective. The research was taken to measure the properties of fresh concrete mixture of Synthetic Macro-fiber reinforced concrete. And investigated the influence of fiber length and volume fraction on the impact resistance of Synthetic Macro-fiber reinforced concrete. The results showed that these fibers could obviously improve the impact resistance of concrete. There was a best Synthetic Macro-fiber volume fraction. The length of the Synthetic Macro-fiber had a certain influence on the impact resistance of concrete.

Development and Application of High Performance Green Hybrid Fiber-Reinforced Concrete (HP-G-HyFRC) for Sustainable and Energy-Efficient Buildings

2014 ◽  
Vol 629-630 ◽  
pp. 299-305 ◽  
Author(s):  
Rotana Hay ◽  
Claudia Ostertag
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Industrial Wastes ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Fiber Volume

The synergy of hybrid fibers allows for an enhanced concrete composite performance at a lower fiber volume fraction as compared to other types of fiber-reinforced concrete. This paper outlines the development process and properties of a new concrete composite termed high-performance green hybrid fiber-reinforced concrete (HP-G-HyFRC). Steel and polyvinyl alcohol (PVA) fibers were used as discontinuous reinforcement of the composite. Up to 60% of cement by mass was replaced by industrial wastes comprising slag and fly ash. At water-binder ratio of 0.25 and with the presence of coarse aggregates, careful proportioning of the mix constituents allows for a composite that is highly flowable. At a combined fiber volume fraction of only 1.65%, the composite also exhibits a deflection hardening behavior which is known to be beneficial for both serviceability and durability of structures. The composite was proposed to be used in an innovative double skin façade (DSF) system consisting of 30 mm air gap in between two thin HP-G-HyFRC skins with no main reinforcing rebars. It was shown that the DSF system alone allows for about 7.6% reduction of cooling energy in buildings.

EVALUATION OF COMPRESSIVE STRENGTH OF SYNTHETIC FIBER REINFORCED CONCRETE

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Saman Hedjazi ◽  
Daniel Castillo
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Synthetic Fibers

This paper evaluates the effect of discrete fibers in concrete on the pulse velocity and mechanical properties of FRC. Two different type of synthetic fibers consisting of Polypropylene and Nylon were investigated. The effect of concrete mix proportions such as types of fiber, volume fraction of fiber, water-to-cement ratio (w/c), and curing conditions were examined. An experimental program was designed and conducted on 100 mm x 200 mm cylindrical specimens to evaluate the properties of FRC. The compressive strength obtained from the Compression Test Machine (CTM) was compared to those calculated from UPV. The difference between two types of synthetic fibers on concrete properties were investigated. Results show that the highest compressive strength of Polypropylene Fiber Reinforced Concrete (PFRC) was achieved at 0.5% fiber volume fraction, whereas for Nylon Fiber Reinforced Concrete (NFRC) the highest compressive strength was obtained at 1.0% fiber volume fraction. Additionally, results show that the available equations relating UPV to compressive strength of concrete need modifications when used for different fibers. Therefore, either new or modified empirical equations are needed for better estimation of mechanical properties of FRC.

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