A FRAMEWORK FOR DURABILITY DESIGN AND BOND DETERIORATION DUE TO CORROSION

This paper summarizes the current understanding of the mechanics of bond resistance at the interface between the concrete and plain and deformed steel bars and how it is influenced by the corrosion of the steel reinforcing bars. Some of the available research on analytical models for bond in uncorroded and corroded steel bars is reviewed. The influence of some of the significant parameters influencing the behavior of corroded steel rebars, such as the concrete strength, crack width, extent of rebar corosion (measured by the mass loss or the cross-sectional area loss), concrete cover thickness, bar diameter and the loss of the rebar lugs reported in some recent paper are summarily presented. Based on the overall trends observed, a preliminary design method for durability against deterioration of bond at the steel-concrete interface due to corrosion of rebars is proposed. The need for more research on these and other parameters influencing the phenomenon is stressed before a more reliable design method developed using a semi-probabilistic approach can be developed.

• INTRODUCTION

• BOND AT STEEL-CONCRETE INTERFACE

• DEFORMED STEEL REBARS

• COMPUTER MODELS – UNCORRODED REBARS

• BOND OF CORRODED BARS

• FLY ASH CONCRETE

• COVER THICKNESS-BAR DIAMETER (Cd/_b) RATIO

• CORROSION CRACKING RESISTANCE FACTOR

• CRACK WIDTH AND BAR LUG PERFORMANCE

• DURABILITY DESIGN FRAMEWORK

• PRELIMINARY DESIGN PROCEDURE

• CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES