CONCRETE BRIDGE PROTECTION AND REHABILITATION: CHEMICAL AND PHYSICAL TECHNIQUES. SERVICE LIFE ESTIMATES

This report presents a study on estimating the service life cycle of reinforced concrete bridge components exposed to chloride-laden environments. Current treatment options are identified and an opinion survey was used to obtain first estimates of service life. Because the transport of chloride through concrete is a complex phenomenon, the movement of chloride was modeled as apparent diffusion. Definitions of four categories of corrosive environment were developed from diffusion parameters. The end of functional service life of untreated bridge decks and bridge substructures was defined according to the level of damage for whole deck or worst damaged lane. The decision to rehabilitate was affected by the amount of physical damage, availability of funds/labor, condition of substructure, average annual daily traffic, and distribution of physical damage. To estimate the service life of untreated and rehabilitated bridge decks, data from 52 bridge decks distributed in different environmental conditions were collected. Models estimating the service life of untreated and rehabilitated bridge decks were developed and compared with models developed based on historical data and the time-to-rehabilitate model.