440.4R-04
Prestressing Concrete Structures with FRP Tendons
2004, 35 pp.
$63.50

Fiber-reinforced polymers (FRPs) have been proposed for use instead of steel prestressing tendons in concrete structures. The promise of FRP materials lies in their high-strength, lightweight, noncorrosive, nonconducting, and nonmagnetic properties. This document offers general information on the history and use of FRP for prestressing applications and a description of the material properties of FRP. The document focuses on the current state of design, development, and research needed to characterize and ensure the performance of FRP as prestressing reinforcement in concrete structures. The proposed guidelines are based on the knowledge gained from worldwide experimental research, analytical work, and field applications of FRPs used as prestressed reinforcement. The current development includes a basic understanding of flexure and axial prestressed members, FRP shear reinforcement, bond of FRP tendons, and unbonded or external FRP tendons for prestressing applications. The document concludes with a description of research needs.

Keywords: anchorage; bond length; crack; deflection; deformation; development

length; ductility; fatigue; jacking stresses; post-tensioning; prestressed concrete;

pretensioning; reinforcement ratio; shear; tendon.

Contents:
CONTENTS

Chapter 1—Introduction

1.1—Organization and limitations of document

1.2—Historical development and use of FRP reinforcement

1.3—Design guidelines and technical committees

1.4—Research efforts

1.5—Demonstrations and field applications

1.6—Definitions

1.7—Notation

Chapter 2—FRP tendons and anchorages,

2.1—FRP tendon characterization

2.2—Commercial tendons

2.3—Description of tendons

2.4—Anchorage characterization

Chapter 3—Flexural design

3.1—General considerations

3.2—Strength design methodology

3.3—Balanced ratio

3.4—Flexural design and capacity prediction

3.5—Strength reduction factors for flexure

3.6—Flexural service stresses

3.7—Jacking stresses

3.8—Creep rupture of FRP tendons

3.9—Correction of stress for harped tendons

3.10—Relaxation and friction losses

3.11—Overall design approach

3.12—Ductility or deformability

3.13—Minimum reinforcement

Chapter 4—Serviceability

4.1—General

4.2—Deflection

4.3—Crack width and spacing

4.4—Fatigue

Chapter 5—Shear

5.1—General considerations in design of FRP stirrups

5.2—Shear strength with FRP stirrups

5.3—Spacing limits for shear reinforcement

5.4—Minimum amount of shear reinforcement

5.5—Detailing of shear stirrups

Chapter 6—Bond and development

6.1—Introduction

6.2—Transfer length

6.3—Flexural bond length

6.4—Design considerations

Chapter 7—Unbonded and external tendon systems

7.1—Unbonded prestressed members

7.2—External prestressing

Chapter 8—Pile driving and in-place flexure,

8.1—General

8.2—Demonstration studies

8.3—Discussion

8.4—Conclusions

Chapter 9—Research needs

Chapter 10—References

10.1—Referenced standards and reports

10.2—Cited references

Appendix A—Design example