Reinforced concrete bridge substructures are affected a great deal by chloride ions entering from deicing salts or saltwater. They destroy the passivity of the steel and cause it to corrode. A chloride diffusion spreadsheet model will help us to predict the amount of chloride concentration around the surface at different depths. A diffusion process was assumed for the chloride ingress. The binding materials, surface chloride, chloride diffusion coefficient, age factor and threshold value -all will have a great influence on the outputs of the model. Later, the result of the model is compared with that of another model life-365. Finally, a correlation is developed between the state's practice methods and the outputs from the model. This relationship would be very effective in determining the condition of the substructures of the bridges and in making a decision for either removal or rehabilitation while considering cost and time.