scholarly journals Investigating the Effects of Fiber Reinforced Concrete on the Performance of End-Zone of Pre-Stressed Beams

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2093
Author(s):  
Jalal ◽  
Shafiq ◽  
Zahid
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Polyvinyl Alcohol ◽  
Strain Energy ◽  
Fiber Reinforced Concrete ◽  
Coated Steel ◽  
Fiber Reinforced ◽  
Cracking Behavior ◽  
Industrial Buildings ◽  
Post Tensioned

This paper presents the results of the behavior of end zone of post-tensioned (PT) beams made of fiber reinforced concrete (FRC). The principal aim of using FRC was to enhance the ductility and post-cracking behavior of end-zone of post-tensioned beams. A stronger and tougher end-zone of PT-beams is necessary when it is subjected to dynamic loading. Post-tensioned (PT) beams are typically used for the construction of bridges and industrial buildings, which are often subjected to vibrations and cyclic loading. Pre-mature cracking of the end zone (EZ) of a PT-beam is considered the type of problem that may cause the structural collapse. In this research program, polyvinyl alcohol (PVA) and copper-coated steel (CCS) fibers were used in concrete for improving the EZ performance of PT-beams. The use of FRC caused a 50% reduction in the shear reinforcement within the end zone of the PT-beam, which also avoided the congestion of steel in the end zone. Hence, the concrete was placed homogeneously, and smooth finished surfaces of the beams were obtained. FRC controlled the bursting of the end zone during the transfer of the full pre-stress force, and approximately 25% increment in the strain energy of the end zone was observed, which was also found efficient in strain diminution along the length of the beam.

scholarly journals Mechanical and Post-Cracking Characteristics of Fiber Reinforced Concrete Containing Copper-Coated Steel and PVA Fibers in 100% Cement and Fly Ash Concrete

2021 ◽  
Vol 11 (3) ◽  
pp. 1048
Author(s):  
Asif Jalal ◽  
Luqmanul Hakim ◽  
Nasir Shafiq
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fly Ash ◽  
Fiber Reinforced Concrete ◽  
Coated Steel ◽  
Fiber Reinforced ◽  
Cement Concrete ◽  
Cracking Behavior ◽  
Fly Ash Concrete ◽  
Cracking Characteristics

This experimental study investigated the effects of polyvinyl alcohol (PVA) and copper-coated steel (CCS) on the mechanical properties and the post cracking behavior of fiber reinforced concrete (FRC). In designing high-performance concrete mixes, cement replacement materials are the essential ingredients. Therefore, the research objective was to investigate PVA and CCS fiber’s post-cracking performance in 100% cement concrete and concrete with 80% cement and 20% fly ash. The fiber content was fixed as a 0.3% volumetric fraction. CSS fibers required 15% more superplasticizer to achieve the desired slump of fresh concrete than the PVA fibers. Simultaneously, CCS fibers showed a 10% higher compressive strength than the concrete made of PVA fibers. Both fibers exhibited a similar effect in developing tensile and flexural strength. PVA fibers showed a value of 47 Gpa of secant modulus, and CCS fibers resulted in 37 Gpa in 100% cement concrete. In post-cracking behavior, CCS fibers showed better performance than the PVA fibers. The reason for this is that CCS showed 2.3 times the tensile strength of the PVA fibers. In comparing the two concretes, fly ash concrete showed about 10% higher compressive strength at 56 days and about 6% higher tensile and flexural strength. Similarly, fly ash concrete showed more than 15% first crack strength and flexural toughness than the 100% cement concrete in post-cracking behavior. Fiber-reinforced concrete containing PVA or CCS fibers showed enhanced post-cracking characteristics and its use could be preferred in structural applications.

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 Numerical Simulations of GFRP-Reinforced Columns Having Polypropylene and Polyvinyl Alcohol Fibers

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Liaqat Ali ◽  
Ahsan Nawaz ◽  
Yong Bai ◽  
Ali Raza ◽  
Muhammad Kashif Anwar ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Polyvinyl Alcohol ◽  
Circular Cross Section ◽  
Fiber Reinforced Concrete ◽  
Elastic Model ◽  
Fiber Reinforced ◽  
Hybrid Fibers ◽  
Element Analysis ◽  
Gfrp Bars

The present investigation aims to propose a numerical model for assessing the complex damaging response of glass fiber-reinforced polymer- (GFRP-) reinforced concrete columns having hybrid fibers and confined with GFRP spirals (GFHF columns) under concentric and eccentric compression. Fiber-reinforced concrete (FRC) consists of polyvinyl alcohol fibers (PVA) and polypropylene fibers (PF). A total of six GFHF circular columns were constructed having a circular cross section of 250 mm and a height of 1200 mm. A commercial package ABAQUS was used for the finite element analysis (FEA) of the GFHF columns by using a modified concrete damage plastic (CDP) model for hybrid fiber-reinforced concrete (HFRC). The damaging response of GFRP bars was defined using a linear elastic model. The results depicted that the failure of GFHF columns occurred either in the upper or in the lower half portion with the rupture of GFRP longitudinal bars and GFRP spirals. The decrease in the pitch of GFRP spirals led to an improvement in the axial strength (AS) of GFHF columns. The eccentric loading caused a significant reduction in the AS of columns. The comparative study solidly substantiates the validity and applicability of the newly developed FEA models for capturing the AS of GFHF columns by considering the axial involvement of longitudinal GFRP bars and the confinement effect of transverse GFRP spirals. So, the suggested numerical model having a complex system of equations for HFRC can be used for the accurate analysis of HFRC members.

scholarly journals Tension Stiffening Behavior of Polypropylene Fiber- Reinforced Concrete Tension Members

2021 ◽  
Vol 53 (2) ◽  
pp. 210209
Author(s):  
Aris Aryanto ◽  
Berto Juergen Winata
Keyword(s):  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Tension Stiffening ◽  
Cracking Behavior ◽  
Tension Members ◽  
Polypropylene Fiber Reinforced Concrete ◽  
Fiber Addition

This paper focuses on comparing the behavior of RC tension members with and without the addition of polypropylene fibers at various corrosion levels. Eight cylindrical tensile specimens were tested to evaluate their tension-stiffening and cracking behavior. The content of polypropylene fiber added into the concrete mix was the main variable (0.25%, 0.50%, 0.75%, and 1.0% of total volume). The corrosion level was varied from slight (5%), medium (10%) to severe (30%) and, like the other variables, applied only to 1.0% polypropylene fiber-reinforced concrete (PFRC) specimens. The test results showed that the fiber addition significantly increased the tension-stiffening effect but was largely unable to reduce the effect of bond degradation caused by corrosion. Moreover, the addition of polypropylene fibers was able to improve the cracking behavior in terms of crack propagation, as shown by smaller crack spacing compared to the specimen without fiber addition at the same corrosion level.

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