PERFORMANCE OF REINFORCED CONCRETE PILES EXPOSED TO MARINE ENVIRONMENT

Six marine piles were extracted from the Port of Singapore after 32 years in service. The wharf was repaired 22 years after installation due to excessive corrosion of its under deck structures. Remedial work using the jacketing method with prepacked aggregates and grouting techniques was used to reinstate the deteriorated concrete. The wharf was eventually demolished to make way for modern container facilities. The piles were extracted in the process to examine their residual properties. This present paper compares numerical predictions, using Fick's second law of diffusion, against concentration profile of watersoluble chloride obtained from the atmospheric, tidal and submerged zones of the piles. Concentrations of water-soluble chloride at the level of steel reinforcement were compared with the loss in mass of the reinforcing bars. The results show that the numerical estimates were in good agreement with the actual values of water-soluble chloride concentrations obtained under Singapore conditions. From regression analysis, diffusion parameters and threshold concentrations of water-soluble chloride for steel corrosion were calculated and these provided useful means in design of estimating the service life of concrete in the local marine environment.

• INTRODUCTION

• BACKGROUND

• ANALYTICAL CONSIDERATION

• RESULTS AND DISCUSSION

• CONCLUSIONS

• ACKNOWLEDGEMENTS

• REFERENCES