This study analyzes the National Bridge Inventory in the U.S. to determine the\nrelative structural deficiencies of bridge materials, comparing between the overall national values\nand each state, geographically. The analysis considers the most common bridge construction\nmaterialsââ?¬â?concrete, steel, and prestressed/post-tensioned concrete. The results suggest need to\nreassess the efficacy of best performance practices for steel bridges and for states with structural\ndeficiencies above the national average. Geographic consistency of structurally deficient bridge\ndensity with population density shows need to improve intervention strategies for regions with\nhigher levels of service usage. The study also compares the relative operational lifespan of bridge\nmaterials in each state. The average structurally deficient bridge ages are lower than the 75-year\nlife-cycle expectancy. Prestressed/post-tensioned concrete bridges reveal relatively lower lifespan.\nOver time, concrete and steel bridges show some gradual improvement with decreasing percentage\nof structural deficiency and increasing lifespan. Prestressed/post-tensioned concrete bridges reveal\nshifting earlier accumulation of structural deficiency for a particular age group. The study also reveals\nrelative climate effects. Climate conditions correlate differently with the structural deficiency and life\ncycle of bridge materials in each state. Structurally deficient bridge densities show correlation with\nclimate maps, especially under colder and moist conditions.
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