Critical Literature Review of High-Performance Corrosion Reinforcements in Concrete Bridge Applications

Final Report July 2004 FHWA-RD-04-093 View Table of Contents View PDF Version (465 kb)

FOREWORD

Economic considerations historically have precluded consideration and widespread utilization of high-performance (corrosion-resistant) reinforcements (such as stainless steels) in bridge construction. However, with the advent of life cycle cost analysis as a project planning tool and of a requirement that major bridge structures have a 75–100-year design life, the competitiveness of such steels has increased such that enhanced attention has been focused upon these materials in recent years.

This investigation was initiated to evaluate the corrosion resistance of various categories of high-performance reinforcement, including new products that are becoming available, in bridge structures that are exposed to chlorides. Both long-term (4-year) test yard exposures and accelerated laboratory experiments in simulated concrete pore waters were involved. The ultimate objective is to: (1) evaluate the corrosion properties and rank the different candidate materials; and (2) develop tools and short-term tests to help practitioners project long-term performance in actual structures. This interim report presents the results of a critical literature review of corrosion issues and behavior for high-performance reinforcements as applicable to bridges and as a precursor to the experimental program.

T. Paul Teng, P.E.
Director, Office of Infrastructure
Research and Development

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for its content or use thereof. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trade and manufacturers' names appear in this report only because they are considered essential to the objective of this document.

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TABLE OF CONTENTS

INTRODUCTION

• General
• Overview of Corrosion-Induced Concrete Deterioration Processes
  • General
  • Corrosion Mechanism
  • Representation of Corrosion-Induced Concrete Deterioration
  • Corrosion Control Alternatives
  • General
  • Existing Structures
  • New Structures

CORROSION-RESISTANT REINFORCING STEEL

• General
• Stainless Steels
  • General
  • Relevant Material Properties
  • Corrosion Behavior of Stainless Steels
  • Pitting Mechanism

EXPERIMENTAL METHODS AND FINDINGS

• Background
• Laboratory Studies in Synthetic Aqueous Solutions
• Laboratory Studies with Cementitious Embedments
• Test Yard-Type Exposures
• Cross-Procedural Experiments
• Specific Reinforcement Alloys
  • General
  • Nitronic 33
  • MMFX
  • Proprietary Ferritic Stainless Steels
  • Clad Stainless Steel
• Actual Structures
  • Progresso Pier
  • Detroit, MI (Interstate (I)-696 over Lenox Road)
  • Trenton, NJ (I-295 over Arena Drive)
  • Ontario, Canada

DISCUSSION

BIBLIOGRAPHY

LIST OF FIGURES

• Figure 1. Photograph of a cracked and spalled marine bridge piling
• Figure 2. Schematic illustration of the various steps in deterioration of reinforced concrete due to chloride-induced corrosion
• Figure 3. Schematic polarization curve for stainless steel in an aqueous solution with and without Cl^-
• Figure 4. Schematic anodic polarization curves illustrating dependence of the anodic polarization curve for stainless steels on temperature, Cl^- concentration, and alloy composition
• Figure 5. Schematic illustration of the Øcrit and Øcorr parameters
• Figure 6. Seawater exposure data illustrating a correlation between Øcrit – Øcorr and weight loss due to pitting
• Figure 7. Schematic illustration of the combined effect of pH and Cl^- onØcrit
• Figure 8. Graphical representation of accelerated screening test data at pH 7
• Figure 9. Graphical representation of accelerated screening test data at pH 13
• Figure 10. Most positive corrosion potential for different alloys in solution and in concrete
• Figure 11. Threshold Cl^--OH^- ratio as a function of potential for stainless and carbon steels
• Figure 12.  Threshold Cl^- concentration for different reinforcement types in aqueous solutions of different pH
• Figure 13. Current density as a function of admixed chloride concentration for mortar specimens potentiostatically polarized at 0 mV_SCE
• Figure 14. Time-to-corrosion as a function of admixed Cl^- concentration
• Figure 15. Critical pitting potential as a function of admixed Cl^- concentration for stainless and carbon steel specimens in both carbonated (C) and uncarbonated (UC) mortar. The number in the caption indicates the PREN for each alloy
• Figure 16. Comparison of c_th for welded and unwelded stainless and carbon steel specimens in carbonated and uncarbonated mortar. The number in the caption is the PREN. Where no carbon steel data are indicated, c_th was zero
• Figure 17. Attempted cross correlation of Cl^- threshold on a cement w/o and on a [Cl^-]/[OH^-] basis
• Figure 18. Weight loss of different reinforcements during a 10-year United Kingdom exposure
• Figure 19. Corrosion rate of various mortar-coated reinforcement types in an aqueous macrocell test arrangement
• Figure 20. Corrosion rate of various reinforcement types in concrete slabs undergoing Southern Exposure testing
• Figure 21. Comparison of corrosion rates in the different environments (multiple listings of same alloy represent results for duplicate specimens)
• Figure 22. Corrosion rate of MMFX and carbon steel under cyclic salt fog exposure
• Figure 23. Perspective view of the Progresso pier.
• Figure 24. Photograph of hinged arches and piling
• Figure 25. Corrosion of an exposed reinforcing bar

LIST OF TABLES

• Table 1. Comparison of Øcrit and Øcorr for selected materials
• Table 2. PRE/PREN for some common stainless steels
• Table 3. Polarization resistance and corrosion rate data for CRR candidates in accelerated screening tests at pH 7
• Table 4. Polarization resistance and corrosion rate data for CRR candidates in accelerated screening tests at pH 13

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