PREDICTION OF SERVICE LIFE IN CRACKED REINFORCED CONCRETE STRUCTURES SUBJECTED TO CHLORIDE ATTACK AND CARBONATION

Reinforcing steel bars in reinforced concrete structures are protected from corrosion by passive film on the steel surface inside concrete with high alkalinity. However, when the passive film breaks down due to chloride ion and CO₂ ingressed into the RC structures, corrosion initiates at the surface of steel bars. Then internal pressure by volume expansion of corrosion products in reinforcing bars induces cracking and spalling of cover concrete, which reduces not only durability performance but also structural performance in RC structures. A service life prediction of RC structures subjected to chloride attack is carried out by using a micro-mechanics based corrosion model. The service life prediction model is composed of a chloride penetration model and carbonation model to evaluate the initiation of corrosion and a steel corrosion model to evaluate the rate and the accumulated amounts of corrosion for the cracking of cover concrete. By implementing the models into a finite element analysis program, a time and space dependent corrosion analysis and a service life prediction of RC structures due to chloride attack and carbonation are simulated. The effect of the crack widths and the degree of carbonation on the corrosion and on the service life of the RC structures are analyzed and discussed.

• INTRODUCTION

• CONCRETE DURABILITY ANALYSIS MODEL

• SERVICE LIFE PREDICTION OF CRACKED CONCRETE

• CONCLUSIONS

• REFERENCES