Bridges

Cover of Realising 100-year Bridge Design Life in an Aggressive Environment: Review of the Literature
Realising 100-year Bridge Design Life in an Aggressive Environment: Review of the Literature
  • Publication no: AP-T313-16
  • ISBN: 978-1-925451-40-5
  • Published: 23 November 2016

This report details a literature review on durability issues that affect the service life of reinforced concrete structures.

The review focused on information from sources within Australia and overseas, including published literature, standards, codes and jurisdiction reports.

Recent amendments to test methods, specifications and codes, particularly Section 5.4 (Concrete Durability) of the Australian Standard AS 5100.5 (Bridge Design), are also discussed.

This work informed a program of experimental work focussing on concrete durability.

Also see the related report AP-T317-16 Realising 100-year Design Life of Bridge Structures in an Aggressive Environment: Experimental Work.

  • Summary
  • 1. Introduction
    • 1.1. Issues
    • 1.2. Information Collected for Review
  • 2. Durability Issues
    • 2.1. Amendment of AS 5100.5-2004 – Clause 4
    • 2.2. Durability Planning: Main Issues
    • 2.3. Protective Measures to Increase Service Life
    • 2.4. Current Practice for Long Service Life Prediction
    • 2.5. In-service Maintenance Phase
    • 2.6. Improvement of Current Practice
      • 2.6.1. Code and/or Specification Requirements
      • 2.6.2. Prediction of Service Life
      • 2.6.3. Use of Stainless Steel
  • 3. Definition of Service Life
  • 4. Performance of Reinforced Concrete Materials
    • 4.1. Reinforcing Steel Corrosion
    • 4.2. Mitigation of Steel Corrosion
    • 4.3. Alternatives to Conventional Reinforcing Steel
      • 4.3.1. Epoxy-coated Bars
      • 4.3.2. Galvanised Steel Bars
      • 4.3.3. Stainless Steel Bars
      • 4.3.4. Carbon Steel Bar Coupled with Stainless Steel Bar
    • 4.4. Defects Formed in Concrete at Early Ages
      • 4.4.1. Thermal Cracking
      • 4.4.2. Delayed Ettringite Formation
    • 4.5. Long-term Durability Problems of Concrete
      • 4.5.1. Carbonation of Concrete
      • 4.5.2. Chloride-induced Steel Corrosion – the Threshold Value
      • 4.5.3. Corrosion Rate Increase with Chloride Content
      • 4.5.4. Steel Corrosion in Carbonated Concrete
      • 4.5.5. Salt Scaling/Erosion
      • 4.5.6. Acid Water
      • 4.5.7. Alkali-aggregate Reaction
      • 4.5.8. Structures Affected by AAR in Australia
      • 4.5.9. Diagnosis of AAR and Characterisation of Concrete
      • 4.5.10. Test Methods for Detecting Reactive Aggregates
      • 4.5.11. Sulfate Attack
      • 4.5.12. Acid Sulfate Soil
      • 4.5.13. Physical Salt Attack
    • 4.6. Surface Coating Treatments for Attack Mitigation
  • 5. Prediction of Service Life
    • 5.1. Time to Onset of Potential Failure
      • 5.1.1. Diffusion Coefficient Variations – Dependence on Temperature and Time
      • 5.1.2. Carbonation Rate
    • 5.2. Time to Detectable Failure Due to Steel Corrosion
      • 5.2.1. Time to Corrosion-induced Cover Cracking
    • 5.3. Time to Functional Failure Due to Steel Corrosion
    • 5.4. Probability of Failure
  • Penetration of Chloride Ions into Concrete
  • 6. Tests for The Evaluation of Durability
    • 6.1. Resistance of Concrete to Chloride Penetration
      • 6.1.1. Apparent Chloride Diffusion Coefficient of Concrete Exposed to Seawater
      • 6.1.2. Accelerated Tests for Chloride Diffusion Coefficient
    • 6.2. Other Transport Properties of Concrete
      • 6.2.1. Apparent Volume of Permeable Voids
      • 6.2.2. Water Sorption Test
      • 6.2.3. Resistance to Carbonation
    • 6.3. Tests for Preventable Potential Durability Problems
      • 6.3.1. Alkali-aggregate Reactivity
      • 6.3.2. Resistance to Sulfate and Acid Attacks
    • 6.4. Corrosion of Stainless Steels
  • 7. Summary and Conclusions
    • 7.1. Materials for Experimental Work (Austroads 2016)
      • 7.1.1. Concrete Materials
      • 7.1.2. Steel Component
  • References
  • Appendix A Comparison of Requirements for Concrete Mix Design and Durability by Four Jurisdictions
  • Appendix B Threshold Values for Steel Corrosion
  • B.1 Carbon Steel
  • B.2 Stainless Steel
  • Appendix C Exposure Conditions of Gateway Bridge Site
  • C.1 Chemical Composition of the Brisbane River Water
  • C.2 Soil Analysis Results
  • Appendix D PSTR Requirements for Design Life
  • D.1 PSTR Requirements for Concrete Mix
  • Appendix E Calculation of Accumulated Corrosion
  • Appendix F Minimum Design Life of Bridges and Bridge Sub-Assets (as per Roads and Maritime (2012a) – Gerrinong Upgrade)