In this book, deep investigations have been conducted for the effects of various environmental actions namely, chloride, temperature, oxygen, carbonation and moisture on the corrosion of reinforcing steel in concrete through extensive experimentation and modeling for the environment variables that have been overlooked in the past research. A semi-experimental-theoretical approach was adopted. The enhanced corrosion model being in close agreement with the experiment results predicts the corrosion rate and potential of steel in concrete for mass and energy transport through porous media with good accuracy and precision. Influential parameters on prediction of corrosion in RC structures involving the severe environmental loadings are experimentally determined and numerically discussed through parametric study. Appropriate parameters for material modeling of corrosion on the basis of present computational scheme are successfully identified by experimentation.