Consider it Bridge Week or Bridge Days, as the Lake Champlain Bridge center span is set for floating and lifting any day now.
Hardly any structure proves to be permanent; very few materials hold up for eternity. Concrete is a particularly troublesome material to many because moisture and salt and lack of maintenance equal a recipe for structural failure. Yes, I am referencing the 1929 Lake Champlain Bridge; but I am also thinking about the small concrete bridges across the nation. These bridges have concrete decks and concrete piers and railings, and we are losing them at an exponential rate.
Often, these small bridges face the fate of poor hydraulics or structural and geometric inadequacies; simply put, they do not meet AASHTO standards and any projects that rehab these bridges are required to bring them up to federal standards and code. But because these bridges were so ubiquitous in the middle decades of the 20th century, they are hardly significant, according to many. Some are significant for technology or design or engineering, but mostly they come across as yesterday’s steel girder, single span (i.e. boring) bridges. Furthermore, repairs to these bridges have destroyed their integrity, and with that, any eligibility for significance.
However, I have recently found myself disheartened by the fate of these bridges; I love small concrete bridges with decorative concrete piers and interesting railings. Whenever I cross a new 3 bar aluminum (or worse! steel w-beam type) bridge, I wonder what it has replaced and when. Alignments have likely been straightened and a bridge with character destroyed. (Go ahead, call me a transportation preservation nerd; blame it on the day job).
Covered bridges are adored and respected. Metal truss bridges are heading in that direction. But, concrete bridges that aren’t elaborate concrete arch bridges are often overlooked. I’m working on understanding the context and significance of small concrete bridges so I can either a) come to terms with the fate of such bridges or b) convince others of their importance. That doesn’t mean that I am the only one who thinks about concrete bridges, but I am looking for others who would like to talk about them. We can’t save everything in preservation, nor should we, but as time passes we need to reevaluate what is important, what is diminishing, what has been insignificant, and figure out what to do with these resources. How are they treated differently if they are out on a dirt road in the middle of nowhere v. in a historic district. (Okay, that’s probably an easy answer, but what if the concrete is indicative of the landscape and a certain era of road travel?)
What are your thoughts on small concrete bridges? For now, I’m still pondering and gathering any historical context I can find.