SERVICE LIFE AND COST COMPARISONS FOR FOUR TYPES OF CDOT BRIDGE DECKS

This study examines costs and performance of four types of reinforced concrete bridge decks currently in service on Colorado Department of Transportation (CDOT) highway bridges. These four types allow a comparison between bare decks and decks with waterproofing membranes, and between decks with uncoated steel reinforcement and decks with epoxy-coated steel reinforcement. Histories of deck condition ratings are used to estimate deck service life and to generate population models of service life. Decks with waterproofing membrane have longer service life than bare decks. Condition data indicate longer service life for decks with uncoated reinforcing steel, but this outcome may be due to the limited extent of condition data for decks having epoxy-coated reinforcement. Costs for bridge decks are evaluated as initial costs, present values, and annualized costs. By all present value and annualized cost measures, decks with waterproofing membrane are least expensive. This outcome is not sensitive to the value of the discount factor.