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.

Losses in partially prestressed concrete

1988 ◽  
Vol 15 (5) ◽  
pp. 890-899
Author(s):  
B. DeV. Batchelor ◽  
Jayanth Srinivasan ◽  
Mark F. Green
Keyword(s):  
Key Words ◽  
Prestressed Concrete ◽  
Effective Modulus ◽  
Highway Bridge ◽  
Design Code ◽  
Bridge Design ◽  
Prestress Losses ◽  
Concrete Members ◽  
Modulus Method

The calculation of prestress losses by the age-adjusted effective modulus method is analyzed and compared with the Ontario highway bridge design code predictions for partially prestressed concrete. Specifically, the effect of nonprestressed reinforcement on prestress losses is studied. The age-adjusted effective modulus method for calculating prestress losses is outlined, and plots of prestress losses versus partial prestressing ratio are presented and analyzed. It is shown that prestress losses decrease with increasing amounts of nonprestressed reinforcement. Also, the Ontario highway bridge design code expressions, which are intended for use with fully prestressed sections, are not suitable for use in the design of partially prestressed concrete members. Key words: concrete (prestress), design, partial prestressing, prestress losses.

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

2007 ◽  
Vol 34 (10) ◽  
pp. 1379
Author(s):  
A A Mufti ◽  
B Bakht ◽  
N Banthia ◽  
B Benmokrane ◽  
G Desgagné ◽  
...  
Keyword(s):  
Highway Bridge ◽  
Code Design ◽  
Design Code ◽  
Bridge Design

Evaluation of the new Canadian highway bridge design code shear provisions for concrete beams with fiber-reinforced polymer reinforcement

2008 ◽  
Vol 35 (6) ◽  
pp. 609-623 ◽  
Author(s):  
Ahmed K. El-Sayed ◽  
Brahim Benmokrane
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Highway Bridge ◽  
Test Results ◽  
Fiber Reinforced ◽  
Design Code ◽  
Bridge Design ◽  
Shear Design ◽  
Reinforced Polymer

The Canadian highway bridge design code (CHBDC) contains provisions for designing concrete members with fiber-reinforced polymer (FRP) reinforcement. In the second edition of the code, new shear design procedures for FRP-reinforced sections are provided. These procedures are consistent with those for steel-reinforced members in the code, in consideration of some modifications that account for the substantial differences between FRP and steel reinforcement. The shear approach adopted in the CHBDC follows the traditional approach of Vc + Vs for shear design. This paper presents an evaluation of this approach by comparing it with experimental shear strengths of available test data on beams longitudinally reinforced with FRP bars and with or without FRP stirrups. In addition, the CHBDC approach was compared with the FRP shear design provisions currently in effect in North America using the available test results. The comparison shows that the CHBDC method significantly underestimates the shear strength of FRP-reinforced concrete beams. A proposed modification to this method is presented and verified against available test results.

Reply to the discussion by A.K. El-Sayed on “New Canadian Highway Bridge Design Code design provisions for fibre-reinforced structures”

2007 ◽  
Vol 34 (10) ◽  
pp. 1378
Author(s):  
A A Mufti ◽  
B Bakht ◽  
N Banthia ◽  
B Benmokrane ◽  
G Desgagné ◽  
...  
Keyword(s):  
Highway Bridge ◽  
Code Design ◽  
Design Code ◽  
Bridge Design

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.

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