1. Service Life Prediction Model for Concrete Structures

2. LIFE-365
Simplistic model for predicting the service life and life-cycle costs of reinforced concrete exposed to chlorides

3. History of LIFE 365
NIST workshop outlined the need for a consensus corrosion service life model.
1999 – ACI Strategic Development Council (SDC) formed a consortium to fund LIFE 365 development.
August LIFE 365 v1 released
2005 – second consortium formed to continue development and improvement of LIFE 365.
January 2008 LIFE 365 v2 released

4. Service Life
Construction to First Repair

5. Two Stage Service Life Model
Figure 4.1 Two-Stage Service Life Model Proposed by Tuutti (1982)
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Figure 4.1
Tuuti

6. Initiation Period
Time for Chloride to penetrate to the rebar, accumulate to threshold to initiate corrosion.

7. Initiation Period Model
Diffusion Mechanism
Fick’s Second Law
Finite Element Model
Inputs
Cover
Quality
Exposure
Threshold

8. Propagation Period
Time necessary for sufficient corrosion to require repair

9. Propagation Period Model
Assign a fixed value - will be modeled in the next version

10. Input Parameters Cs Surface concentration of chloride ion
D Diffusion coefficient
M Diffusion decay coefficient
Ct Chloride threshold
tp Propagation period
T Temperature