Load-Carrying Capacity of a Fiber-Reinforced Annular Tree-Layer Composite Plate Clamped on its External and Internal Contours

2016 ◽  
Vol 52 (2) ◽  
pp. 271-280 ◽  
Author(s):  
A. A. Jahangirov
Keyword(s):  
Carrying Capacity ◽  
Composite Plate ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Layer Composite ◽  
Tree Layer ◽  
Load Carrying

Ultra-Durable Concretes: Structure at the Micro- and Nanoscale

MRS Bulletin ◽  
2004 ◽  
Vol 29 (5) ◽  
pp. 324-327 ◽  
Author(s):  
Christian P. Vernet
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Remarkable Improvement ◽  
Load Carrying ◽  
Wide Particle Size Distribution

AbstractUltrahigh-performance concretes (UHPCs) are obtained by optimizing several technologies: minimizing the amount of water added, using superplasticizers and a wide particle size distribution, and packing the particles to improve fluidity with minimized water additions and to optimize load-carrying capacity. Fibers can be incorporated to increase ductility, leading to ultrahigh-performance fiber-reinforced concretes (UHPFRCs). Such enhanced concretes can approach the compressive strength of steel, with a remarkable improvement in durability. UHPCs offer new solutions for innovative construction, especially in aggressive environments.

Responses of Plain and Steel Fiber-Reinforced Concrete Beams to Temperature and Mechanical Loads: Experimental Study

2000 ◽  
Vol 1740 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ali Alavizadeh-Farhang ◽  
Johan Silfwerbrand
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Load Carrying

To study the structural responses of plain and steel fiber-reinforced concrete pavements under combined mechanical and thermal loads, two test series have been conducted with plain and steel fiber-reinforced concrete beams. The magnitude and duration of the differences in the induced stresses caused by traffic load and a positive nonlinear temperature gradient (the top surface was warmer than the bottom surface during the day) may lead to some relaxation of thermal stresses and subsequently increase the load-carrying capacity. Considering the loss of support contact in the interior part of the concrete pavement, the experimental study of combined loading with restrained concrete beams may provide some insight and an indication of whether the superposition of stresses is a proper approach. The beams were subjected to solely thermal, solely mechanical, and combined thermal and mechanical loads while the rotation of the beam at supports was prevented. The results of tests conducted with both plain and steel fiber-reinforced beams showed that the superposition of stresses under combined loading before cracking gave a satisfactory estimation of the load-carrying capacities. The results also showed that the effect of relaxation of stresses due to short-term thermal loads was not noticeable in the load-carrying capacity achieved in tests with combined thermal and mechanical loads. On the contrary, a tendency for reduction of the load-carrying capacity was observed at higher thermal gradients. In addition, the overall structural responses of steel fiber-reinforced concrete beams under mechanical load and a nonlinear temperature gradient combined were similar to the responses of plain concrete beams up to the cracking stage. However, the release of thermal stresses due to cracking and the considerable residual load-carrying capacity after cracking were the most important observations for steel fiber-reinforced concrete beams.

scholarly journals Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
S. Talukdar ◽  
N. Banthia
Keyword(s):  
Energy Absorption ◽  
Carrying Capacity ◽  
Absorption Capacity ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Bonding Agents ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Timber Beams

A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP) for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

scholarly journals Manufacturing and Performance Evaluation of Carbon Fiber–Reinforced Honeycombs

2019 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
Sanjeev Rao ◽  
Jimmy Thomas ◽  
Alia Aziz ◽  
Wesley Cantwell
Keyword(s):  
Performance Evaluation ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Static Compression ◽  
Epoxy Resin System ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

In this work, the manufacturing characteristics and a performance evaluation of carbon fiber–reinforced epoxy honeycombs are reported. The vacuum-assisted resin transfer molding process, using a central injection point, is used to infuse a unidirectional dry slit tape with the epoxy resin system Prime 20 LV in a wax mold. The compression behavior of the manufactured honeycomb structure was evaluated by subjecting samples to quasi-static compression loading. Failure criteria for the reinforced honeycombs were developed and failure maps were constructed. These maps can be used to evaluate the reliability of the core for a prescribed loading condition. Improvements in the load-carrying capacity for the reinforced samples, as compared with unreinforced specimens, are discussed and the theoretical predictions are compared with the experimental data. The compression test results highlight a load-carrying capacity up to 26 kN (~143 MPa) for a single hexagonal cell (unit cell) and 160 kN (~170 MPa) for cores consisting of 2.5 × 3.5 cells. The failure map indicates buckling to be the predominant mode of failure at low relative densities, shifting to cell wall fracture at relative densities closer to a value of 10−1. The resulting energy absorption diagram shows a monotonic increase in energy absorption with the increasing t/l ratio of the honeycomb core cell walls.

Eccentricity-based design-oriented model of fiber-reinforced polymer-confined concrete for evaluation of load-carrying capacity of reinforced concrete rectangular columns

2016 ◽  
Vol 35 (23) ◽  
pp. 1734-1758 ◽  
Author(s):  
Mohamed F M Fahmy ◽  
Omar A Farghal
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Fiber Reinforced Polymer ◽  
Confined Concrete ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Rectangular Columns

This study aimed to evaluate the load-carrying capacity of reinforced concrete rectangular columns confined with fiber-reinforced polymer composites and subjected to small eccentric loading. Seven design-oriented models of fiber-reinforced polymer-confined concrete were implemented in OpenSees software to establish the theoretical axial force-moment interaction diagram for rectangular columns. The examined models were categorized into two types: stress–strain models developed for fiber-reinforced polymer-confined non-circular concrete tested under the effect of concentric loading and others designed for fiber-reinforced polymer-confined non-circular concrete subjected to eccentric loading. The accuracy of these models was examined against the experimental results of eccentrically loaded fiber-reinforced polymer-confined reinforced concrete rectangular columns. Results indicated that the local stress–strain law obtained from the concentric compression tests would not reflect very well the local behavior of the compression zone of fiber-reinforced polymer-reinforced concrete members subjected to the combined effect of flexural and axial loadings. Adoption of a rational approach reflecting the impacts of eccentric loadings on the stress–strain relationship of the fiber-reinforced polymer-confined concrete revealed a much better evaluation of the load-carrying capacity of both reinforced concrete rectangular columns and plain concrete square columns under the effect of axial loads with various eccentricities.

scholarly journals A Study on the Strengthening Performance of Concrete Beam by Fiber-Reinforced Polyurea (FRPU) Reinforcement

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jun-Hyuk Song ◽  
Eun-Taik Lee ◽  
Hee-Chang Eun
Keyword(s):  
Carrying Capacity ◽  
Concrete Beams ◽  
Glass Fibers ◽  
Concrete Surface ◽  
Strengthening Effect ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Content Ratio ◽  
Load Carrying ◽  
Flexural Ductility

Polyurea coating helps improve the ductility and toughness of structural members. A fiber-reinforced polyurea (FRPU) composite provides high load-carrying capacity and is applied by simply spraying it onto the member surface. Unlike existing reinforcement approaches, the FRPU coating method can prevent the ductility of concrete beams from deteriorating and the concrete surface from debonding. In this study, 20 concrete beams were tested with respect to their load-carrying capacity and flexural ductility using polyurea or FRPU reinforcement. The test variables included the type of reinforcing fibers, coating thickness, and weight-to-content ratio of the fibers in the FRPU. Moreover, the load-carrying capacity and mechanical behavior of all specimens were compared according to the content of the steel fibers, milled glass fibers, or carbon nanotubes (CNTs). Specimens reinforced using polyurea or FRPU were confirmed to retain the load-carrying capacity and flexural ductility to a certain degree after concrete failure at the tension face of the midspan section. The concrete beams ultimately failed through the fracture of polyurea or FRPU without debonding. Experiments were conducted to illustrate the strengthening effect by FRPU and determine its superiority.

Damage Theory for Discontinuously-Reinforced Composites Including Cracked Inhomogeneity

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1801-1807
Author(s):  
Young Tae Cho ◽  
Duck Young Yoon ◽  
Kwang Hee Im
Keyword(s):  
Carrying Capacity ◽  
Short Fiber ◽  
Fiber Reinforced Composites ◽  
Load Carrying Capacity ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Infinite Body ◽  
Equivalent Inclusion Method ◽  
Load Carrying ◽  
Damage Theory

In particle or short-fiber reinforced composites, cracking of the reinforcements is a significant damage mode because the cracked reinforcements lose load carrying capacity. This paper deals with an incremental damage theory of particle or short-fiber reinforced composites. The composite undergoing damage process contains intact and broken reinforcements in a matrix. To describe the load carrying capacity of the cracked reinforcement, the average stress of a cracked ellipsoidal inhomogeneity in infinite body, which was proposed in the previous paper is introduced. An incremental constitutive relation of particle or short-fiber reinforced composites including the progressive cracking damage of the reinforcements have been developed based on the Eshelby's equivalent inclusion method and Mori and Tanaka's mean field concept. Influence of the cracking damage on the stress-strain response of the composites is demonstrated.

scholarly journals Rehabilitation of Reinforced Concrete Deep Beams Using Carbon Fiber Reinforced Polymers (CFRP)

2018 ◽  
Vol 12 (8) ◽  
pp. 179 ◽  
Author(s):  
Shereen K. H. Hassan ◽  
Mu`tasim S. Abdel-Jaber ◽  
Maha Alqam
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Carrying Capacity ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Deep Beams ◽  
Reinforced Polymer ◽  
Cfrp Composites ◽  
Load Carrying

Reinforced concrete structures that incorporates deep beams are generally susceptible to deterioration due to weathering effects and sulphur attacks, under-design in the detailing of concrete cover and/or reinforcement, and construction errors. In lieu of demolishing and replacing these structures, rehabilitation and strengthening using carbon fiber composites becomes a cost-effective viable alternative. Recent advances in research and innovation have introduced concrete repair and strengthening systems that are primarily based on fiber reinforced polymer composites. These systems have offered engineers the opportunity to provide additional stability to the structural elements in question and to restore the damaged portions back to their original load carrying capacity.  This paper investigates the effect of Carbon Fiber Reinforced Polymer (CFRP) composites in enhancing the flexural performance of damaged reinforced concrete deep beams. Two types of CFRP composites and epoxy were used in the experimental investigation carried out and as described by this paper: 1) high strength carbon fiber reinforced polymer (CFRP) plates, commercially known as MBrace Laminate, that are bonded using an epoxy resin specifically suited for the installation and used to strengthen existing structural members; and, 2) MBrace Fiber 230/4900, a 100% solids, low viscosity epoxy material that is used to encapsulate MBrace carbon, glass, and aramid fiber fabrics so that when it cures, it provides a high performance FRP sheet.Test samples were divided into four groups: A control group, and three rehabilitated test groups with CRFP fibers, where the main variable among them was the percent length of CRFP used along the bottom beam extreme surface between supports (i.e, for two of the groups reinforced with MBrace laminates), and the use of MBrace Fiber 230/4500 CRFP sheets on the 4th beam along its vertical sides as well as the bottom extreme face between supports. All beams had similar cross-sectional dimensions and reinforcement, and were designed to fail in flexure rather than shear. The results show that CFRP composites, both laminated and sheet type, have increased the load carrying capacity in comparison to the control specimen, where observations were recorded pertaining to the delayed formation of vertical flexural cracks at the section of maximum moment, and diagonal shear cracks at beam ends. The increase in the load carrying capacity varied among the three rehabilitated test group beams, with the 4th group showing the highest ultimate load carrying capacity when compared to the control specimen. 

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