Damage Tolerance of Reinforced Concrete (RC) Beams with a Layer of PE Fiber Reinforced Strain-Hardening Cement Composite (PE-SHCC)

2013 ◽  
Vol 372 ◽  
pp. 219-222
Author(s):  
Yeon Jun Yun ◽  
Seok Joon Jang ◽  
Hyun Do Yun

This work evaluated the applicability of polyethylene (PE) fiber reinforced strain-hardening cement composite (PE-SHCC) layer at the bottom of reinforced concrete (RC) beams to improve the flexural performance and cracking behavior. PE-SHCC material with specific compressive strength of 70MPa was reinforced with 1.5% PE fibers at the volume fraction. Four RC beams with cross-section of 130 x 170mm and length of 1,460mm were made and tested under four-point monotonic loading. Three beams were layered with PE-SHCC material and one whole RC beam was a control specimen for comparison. Principal variable is the thickness of PE-SHCC layer; 20, 40 and 60mm that are equivalent to 11, 23 and 35% of beams depth. Experimental results indicated that the addition of PE-SHCC layer enhanced the crack-damage mitigation of RC beams and improve the structural behavior, such as strength and ductility, of RC beams.

2010 ◽  
Vol 168-170 ◽  
pp. 2037-2043
Author(s):  
Yin Gu ◽  
Wei Dong Zhuo ◽  
Yu Ting Qiu

This paper proposes a concept of layered fiber reinforced concrete (LFRC) beam. In the concept of a LFRC beam, low-modulus fiber and high-modulus fiber are randomly dispersed and uniformly distributed into the concrete matries of the compression and tension zones, respectively. The static behaviors of LFRC beam are investigated from both experimental and numerical aspects. Four-point bending tests are performed on two simply supported T-shaped LFRC beam specimens and an ordinary T-shaped RC beam specimen with large scales. Comparison between the testing results of LFRC and RC beam specimens shows that the initial cracking load, flexural toughness and post-yielding stiffness of a LFRC beam can be significantly improved, but the ultimate loads are nearly without change. Numerical simulations are also carried out to investigate the static behaviors of the LFRC beam specimens. It is found that the simulation results are agreed well with that of tests. Further numerical parameter analysis for the LFRC beam specimens is conducted. The effects of high-modulus fiber volume fraction on the static behaviors of LFRC beams are studied. The research results show that the additions of high-modulus fibers have little effect on the initial stiffness, yielding loads and ultimate loads of LFRC beams; both the load and displacement at the initial cracking point increase linearly with the increasing volume fraction of the high-modulus fiber, but both the yielding displacement and ultimate displacement decrease linearly with the increasing volume fraction of the high-modulus fiber.


2006 ◽  
Vol 33 (6) ◽  
pp. 726-734 ◽  
Author(s):  
Fariborz Majdzadeh ◽  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Pitcha Jongvivatsakul ◽  
Linh V. H. Bui ◽  
Theethawachr Koyekaewphring ◽  
Atichon Kunawisarut ◽  
Narawit Hemstapat ◽  
...  

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.


2011 ◽  
Vol 243-249 ◽  
pp. 5618-5623
Author(s):  
Jian Hui Li ◽  
Ying Li ◽  
Zong Cai Deng

The research program is aimed at investigating the effectiveness of application of good ductile hybrid fiber reinforced polymer (FRP) to upgrade corroded RC beams. A total of 5 RC beams are tested under flexural load, the results show that compared with the un-strengthened corroded RC beam, the crack, yield, maximum and ultimate load of corroded RC beam strengthened with hybrid FRP sheets is increased by 14%, 35%, 102% and 109% respectively, and the displacement ductility factor is only decreased by 11%, which indicate that the hybrid FRP sheets can improve significantly the flexural performance of corroded RC beam.


2013 ◽  
Vol 658 ◽  
pp. 34-37 ◽  
Author(s):  
Seung Ju Han ◽  
Hyun Do Yun

This experimental study investigates the flexural behavior and toughness of sprayable strain-hardening cement composite (SHCC) developed to retrofit seismically reinforced concrete structures with non-ductile reinforcement details. Three SHCC mixtures with specified compressive strength of 50 MPa are mixed and tested. All SHCC mixes with different dosage and combination of admixtures such as superplasticizer and powder admixture were reinforced with 2.2 % polyvinyl alcohol (PVA) fibers at the volume fraction. This paper focuses on the flexural toughness based on the flexural test results for 100 x 100 x 400 mm prisms. The flexural toughness is evaluated in accordance with ASTM C 1018. The results indicated that less than 2.5 % dosage of hybrid superplasticizer and powder admixtures respectively provides excellent sprayability and flexural behavior of SHCC mixed in this study. A strong influence of hybrid superplasticizer and powder admixture on the flexural toughness of SHCC mixes was observed.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Wonchang Choi ◽  
Seok-Joon Jang ◽  
Hyun-Do Yun

This research investigates the interfacial behavior between polyethylene (PE) fiber-reinforced strain-hardening cement composite (PE-SHCC) and reinforcing bars that are spliced in the tension region to determine feasibility of reduced lap-spliced length in PE-SHCC. Twenty test specimens were subjected to monotonic and cyclic tension loads. The variables include the replacement levels of an expansive admixture (0% and 10%), the compressive strength of the SHCC mixtures (40 MPa and 80 MPa), and the lap-spliced length in the tension region (40% and 60% of the splice length recommended by ACI 318). The PE-SHCC mixture contains polyethylene fiber to enhance the tensile strength, control the widths of the cracks, and increase the bond strength of the lap splice reinforcement and the calcium sulfo-aluminate- (CSA-) based expansive admixture to improve the tension-related performance in the lap splice zone. The results have led to the conclusion that SHCC mixtures can be used effectively to reduce the development length of lap splice reinforcement up to 60% of the splice length that is recommended by ACI 318. The addition of the calcium sulfo-aluminate-based expansive admixture in the SHCC mixtures improved the initial performance and mitigated the cracking behavior in the lap splice region.


2020 ◽  
Vol 25 (1) ◽  
Author(s):  
Kathiresan Karuppanan ◽  
Vennila Govindasamy

ABSTRACT This paper presents the flexural performance of newly developed hybrid fiber reinforced concrete-filled steel tubular sections. The test parametres are fiber volume fraction and fiber hybridation ratio. Initially mechanical properties studied for 10 mono fiber reinforced concrete mixes using steel and Polypropylene fibres with 0.5%, 1.0%, 1.5%, 2.0% and 2.5% volume fraction. Based on the performance optimum fiber dosage was determined in each fiber, with the same volume fraction three different fiber hybridation was developed. Developed hybrid fiber reinforcement concrete, conventional concrete and optimum mono fiber reinforced concrete was used in the concrete-filled steel tubular beams and columns to determine the structural performance. The test results shows that, fiber reinforced concrete-filled steel tubular beams display significant improvement in the flexural performance.


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Seok-Joon Jang ◽  
Sun-Woo Kim ◽  
Wan-Shin Park ◽  
Koichi Kobayashi ◽  
Hyun-Do Yun

This paper describes the effects of expansive admixture on the mechanical properties of strain-hardening cement-based composite (SHCC) mixtures. Also, this study investigates structural performance of reinforced concrete (RC) beam specimens repaired with SHCC and Ex-SHCC (SHCC with expansive admixture). In this study, SHCC and Ex-SHCC mixtures with two specified compressive strength values of 30 MPa and 60 MPa and the fiber volume fraction of 1.5% were investigated. The expansive admixture replacement ratio of 10% by cement weight was used in this study. The test results indicate that the compressive, tensile, and flexural strength values of the SHCC mixtures increased when expansive admixture was included in the mix; however, their toughness and ductility decreased. The study results also show that the application of both SHCC and Ex-SHCC mixtures to repair damaged RC beam specimens can lead to significant structural performance improvement by mitigating crack damage and increasing ductility.


Sign in / Sign up

Export Citation Format

Share Document