Life-cycle cost based maintenance plan for steel bridge protection systems

Life-cycle cost analysis was used to compare different alternative strategies for steel bridge paint systems. It was also used as a tool for steel bridge paint rehabilitation planning. The existing paint systems are lead-based and zinc-vinyl, while the new system is an inorganic/organic zinc, epoxy, and urethane paint system (three-coat). Economic analysis using present value (PV) and equivalent uniform annual cost (EUAC) was applied to compare several steel bridge paint system alternatives. The PV and EUAC were also used to compare different rehabilitation scenarios within the same alternative. Life-cycle cost analysis computations indicate that the three-coat paint system was better than others. Researchers concluded that the best scenario for three-cost system rehabilitation was doing spot repairs every 15 years of paint life. A maintenance plan based on life-cycle cost analysis also favored the "spot repairs every 15 years" scenario. A sensitivity analysis was also conducted to account for uncertainty in the cost, conditions, and subjective data.