Effects of driving forces and bending fatigue on structural performance of a novel concrete-filled fibre-reinforced-polymer tube flexural pile

2006 ◽  
Vol 33 (6) ◽  
pp. 683-691 ◽  
Author(s):  
Karim Helmi ◽  
Amir Fam ◽  
Aftab Mufti ◽  
J Michael Hall
Keyword(s):  
Prestressed Concrete ◽  
Driving Forces ◽  
Marginal Effect ◽  
Lateral Loads ◽  
Bending Fatigue ◽  
Reinforced Polymer ◽  
Composite Pile ◽  
Fibre Reinforced Polymer ◽  
Ultimate Moment ◽  
Prestressed Piles

The effects of driving forces and high-cycle fatigue on the flexural performance of a novel pile consisting of a concrete-filled glass-fibre-reinforced polymer (GFRP) tube (CFFT) are investigated. A 367 mm diameter CFFT pile was driven and then extracted from the ground. Two 6 m segments cut from the upper and lower ends of the pile were tested to failure under monotonic bending and compared with a similar undriven CFFT pile. In addition, a 625 mm diameter CFFT and a conventional 508 mm square prestressed concrete pile of similar moment capacities, both 13.1 m long, were driven, tested in the field under lateral loads, and compared. It was found that driving forces have a marginal effect (about 5% reduction) on the flexural strength of CFFT piles. Also, CFFT piles have larger deflections than prestressed piles do. Because the GFRP tube is the sole reinforcement for the CFFT system, a comprehensive fatigue test program was conducted: coupons cut from the tube were tested under cyclic loading at various stress levels (20%–60% of ultimate) to establish the S–N curve and stiffness-degradation characteristics of the tube. A full-scale 367 mm diameter and 6 m long CFFT pile was tested under reversed cyclic bending at 60% of ultimate moment to validate the coupon test results. It is recommended that the service moment be limited to 20%–30% of ultimate moment to achieve at least 1 million cycles.Key words: composite pile, CFFT, driving, bending, fatigue, cyclic, FRP, tension.

Carbon Footprint Analysis of Fibre Reinforced Polymer (FRP) Incorporated Pedestrian Bridges: A Case Study

2012 ◽  
Vol 517 ◽  
pp. 724-729
Author(s):  
Jian Guo Dai ◽  
Tamon Ueda
Keyword(s):  
Construction Industry ◽  
Carbon Footprint ◽  
Prestressed Concrete ◽  
Environmental Friendliness ◽  
Pedestrian Bridge ◽  
Reinforced Polymer ◽  
Pedestrian Bridges ◽  
Fibre Reinforced Polymer ◽  
Footprint Analysis

This paper presents a case study on the carbon footprint of a fibre reinforced polymer (FRP)-incorporated pedestrian bridge in comparison with a conventional prestressed concrete (PC) one. The CO2 emission is used as an index and calculated for both the material manufacturing and the construction processes. It is shown that using an FRP-incorporated pedestrian bridge to replace a conventional prestressed concrete (PC) bridge may reduce the CO2 emission by 18% and 70%, respectively, during the material manufacturing and construction periods, leading to a total reduction by about 26%. Such reduction is expected to be more significant if the life-cycle CO2 emission is accounted for, since the former type of bridge is free of corrosion and almost maintenance-free. Therefore, FRP-incorporated bridges may become a more competitive alternative to conventional reinforced concrete (RC) or PC ones with the increasing attention paid on the sustainability and environmental friendliness of construction industry by our society.

Strengthening precast-prestressed hollow core slabs to resist negative moments using carbon fibre reinforced polymer strips: an experimental investigation and a critical review of Canadian Standards Association S806-02

2006 ◽  
Vol 33 (8) ◽  
pp. 955-967 ◽  
Author(s):  
Abdelhadi Hosny ◽  
Ezzeldin Yazeed Sayed-Ahmed ◽  
Amr Ali Abdelrahman ◽  
Naser Ahmed Alhlaby
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Bending Moments ◽  
Hollow Core ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Negative Moment ◽  
Fibre Reinforced Polymer ◽  
Prestressing Strands ◽  
Negative Moments

Behaviour of precast-prestressed hollow core slabs has been extensively studied when these slabs are subjected to positive bending moments, a practical application typical of hollow core slabs. However, in many projects it may be required to have an overhanging part of the roof to act as a cantilever. In doing so, and using precast-prestressed hollow core slabs, the slabs would be subjected to negative moments, atypical for hollow core slabs. In this paper, the behaviour of precast-prestressed hollow core slabs is experimentally investigated when they are subjected to negative bending moments. A proposed strengthening detail to increase the negative moment resistance of hollow core slabs using bonded carbon fibre reinforced polymer (CFRP) strips is presented. The CFRP strips were bonded to the top side of full-scale precast-prestressed hollow core slabs in the negative moment zone in different configurations. In two of the tested slabs the bond between the prestressing strands and the concrete was initially broken (during casting of the slabs) in the negative moment zone. The slabs with the bonded CFRP strips were tested to failure and the load–deflection behaviour was recorded. The results of the tests are presented and the strength enhancement of the hollow core slabs using the proposed technique is reported. The increase in the negative moment resistance of the CFRP-bonded hollow core slabs experimentally determined is also compared with the CSA-S806-02 prediction for the moment resistance of concrete elements with bonded CFRP strips.Key words: carbon fibre reinforced polymer (CFRP) strips, hollow core slab, flexure strengthening, prestressed concrete, precast slabs, prestressing strands.

Flexural behaviour of reinforced or prestressed concrete beams including strengthening with prestressed carbon fibre reinforced polymer sheets: application of a fracture mechanics approach

2007 ◽  
Vol 34 (5) ◽  
pp. 664-677 ◽  
Author(s):  
Yail J Kim ◽  
Mark F Green ◽  
R Gordon Wight
Keyword(s):  
Fracture Mechanics ◽  
Size Effect ◽  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Mechanics Model ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper describes the application of a fracture mechanics model (Hillerborg 1990) to concrete structures, including strengthening with prestressed carbon fibre reinforced polymer (CFRP) sheets. One benefit of the proposed fracture mechanics model, consisting of a unique combined stress–strain response of concrete, is that it includes the size effect of reinforced concrete beams; however, its application and validation have not been fully investigated. The proposed model is reviewed and further developed to cover prestressed concrete beams including a beam strengthened with a prestressed CFRP sheet. To evaluate the model, various approaches such as finite element analysis, a strength-based model, a conventional design method, and experimental results are compared with the fracture mechanics model. The size-dependent parameter (ε1) significantly affects the predicted behaviour of reinforced or prestressed concrete beams, depending on the contribution of reinforcement. Based on the current assessment, ε1 = 0.005 is recommended as an upper limit for normal strength concrete.Key words: carbon fibre reinforced polymer sheet, flexure, fracture mechanics, prestressed concrete beam, reinforced concrete beam, strengthening, size effect.

Fibre reinforced polymer materials for prestressed concrete structures

2003 ◽  
Vol 21 (2) ◽  
pp. 95-101 ◽  
Author(s):  
H.Y. Leung ◽  
R.V. Balendran ◽  
T. Maqsood ◽  
A. Nadeem ◽  
T.M. Rana ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Concrete Structures ◽  
Polymer Materials ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

scholarly journals An Experimental Study on Concrete Flat Slabs Prestressed with Carbon Fibre Reinforced Polymer Sheets

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yin Shen ◽  
Shaohui Lu ◽  
Fangyuan Li
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Utilization Efficiency ◽  
Cfrp Sheets ◽  
Flat Slabs ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Fibre Reinforced Polymer ◽  
Anchoring System ◽  
Fibre Reinforced Polymer

Carbon fibre reinforced polymer (CFRP) is currently used to reinforce buildings in civil engineering in the common forms of sheets, while the utilization efficiency of a CFRP materials greatly decreased when the CFRP material is directly bonded to the structure because of the lack of the effect of the exertion of a prestress. A paper spool-inspired anchoring method is proposed to overcome the shearing problem in the anchoring system through the friction between layers. Anchoring and jack-up tensioning devices for CFRP sheets are also designed and produced. A prestress is successfully applied to single and multiple CFRP sheets (80% tensioning strength is achieved), thus verifying the tensioning effect of the prestress. Based on these results, prestressed concrete flat slabs were designed with pretensioned CFRP sheets. The corresponding mechanical properties of the concrete flat slabs are tested to verify the feasibility of using CFRP sheets to apply a prestress. The results show that the uniformity of the fibre stress during the tensioning of the CFRP sheet is the key to the success of the application of the prestress.

Strengthening of concrete columns with carbon fibre reinforced polymer wrap

2003 ◽  
Vol 30 (3) ◽  
pp. 543-554 ◽  
Author(s):  
P L Shrive ◽  
A Azarnejad ◽  
G Tadros ◽  
C McWhinnie ◽  
N G Shrive
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Concrete Columns ◽  
Element Model ◽  
Maximum Load ◽  
Design Methods ◽  
Reinforced Polymer ◽  
Confining Effect ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

Reinforced and prestressed concrete columns with one or two layers of carbon fibre reinforced polymer (CFRP) wrap were tested to failure in axial compression. When the results were compared with the maximum load predictions of two proposed design methods, the predictions consistently underestimated actual loads. The design methods are thus conservative. A simple analysis for circular columns reveals that the confining effect of the wrap is not engaged until the concrete actually starts failing and dilating. A finite element model of a chamfered square column confirms this analysis, as do strain readings from the tests. It is shown that strength gains are not linearly related to wrap thickness. The failure mechanism suggests that design should not be based on the ultimate strength or strain of the wrap and that strength gains can be expected to reduce with increasing brittleness of the concrete and with increasing eccentricity.Key words: concrete columns, FRP wrap, reinforced, strengthening.

New Canadian Highway Bridge Design Code design provisions for fibre-reinforced structures

2007 ◽  
Vol 34 (3) ◽  
pp. 267-283 ◽  
Author(s):  
A A Mufti ◽  
B Bakht ◽  
N Banthia ◽  
B Benmokrane ◽  
G Desgagné ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Highway Bridge ◽  
Code Design ◽  
Design Code ◽  
Bridge Design ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Deck Slabs ◽  
Fibre Reinforced Polymer ◽  
Precast Construction

This paper presents a synthesis of the design provisions of the second edition of the Canadian Highway Bridge Design Code (CHBDC) for fibre-reinforced structures. New design provisions for applications not covered by the first edition of the CHBDC and the rationale for those that remain unchanged from the first edition are given. Among the new design provisions are those for glass-fibre-reinforced polymer as both primary reinforcement and tendons in concrete; and for the rehabilitation of concrete and timber structures with externally bonded fibre-reinforced-polymer (FRP) systems or near-surface-mounted reinforcement. The provisions for fibre-reinforced concrete deck slabs in the first edition have been reorganized in the second edition to explicitly include deck slabs of both cast-in-place and precast construction and are now referred to as externally restrained deck slabs, whereas deck slabs containing internal FRP reinforcement are referred to as internally restrained deck slabs. Resistance factors in the second edition have been recast from those in the first edition and depend on the condition of use, with a further distinction made between factory- and field-produced FRP. In the second edition, the deformability requirements for FRP-reinforced and FRP-prestressed concrete beams and slabs of the first edition have been split into three subclauses covering the design for deformability, minimum flexural resistance, and crack-control reinforcement. The effect of sustained loads on the strength of FRPs is accounted for in the second edition by limits on stresses in FRP at the serviceability limit state.Key words: beams, bridges, concrete, decks, fibre-reinforced-polymer reinforcement, fibre-reinforced-polymer sheets, prestressing, repair, strengthening, wood.

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