Focus on Bridge Joints: The bridge joint is the interface between the road and the bridge, and it should be at the top of the list for preventative maintenance. Many older bridges incorporated a strip seal of some form to waterproof for the joint. Some bridges lack this joint sealant all together, creating an opening for moisture and debris to accumulate on the bearing seat. Installing and maintaining the joint seal is a low-cost way of avoiding bigger problems in the future and a good way to extend the life of your bridge. Watch for tearing in the seal and make sure to regularly clear objects that could tear into the seal, such as bolts, screws, nails, wood, and even discarded coffee cups and vaping cartridges, which some drivers still consider OK to toss from their vehicles while out on the road. Pay special attention to bridges in high traffic areas where it is more likely road debris will get into the joint.
Replace or Eliminate the Joints: At some point, through a combination of wear and tear along with routine aging, you will need to completely replace the seal. As much as possible, replace joints before they have completely failed to protect the superstructure and substructure below. When it comes to replacements or major rehabilitations, move the bridge joints off the bridge to eliminate the need for future costly maintenance. One solution could be the use of an integral abutment, moving the joint to the end of the approach slab.
Turn Up the Road Sweeper: One of the lowest cost, most effective things you can do to maintain bridge life is to regularly use a road sweeper to clean off your bridges. Removing dirt, sand, rocks, road salt, and objects such as nails, screws, glass, and other items prevents ponding of water that could damage bridge joints. Water is the number one enemy of bridges and allowing it to flow as intended will improve the structure’s service life. Instead of once a year, consider doubling or tripling your bridge cleaning efforts. It is a relatively low-cost method to achieve high return on service life.
Install Remote Water Gauges: One of the most common causes of catastrophic bridge failures is scour, where water removes the soil supporting a bridge’s foundation. Typically, this is a known issue well in advance of the failure, as identified in biennial inspection reports. Consider installing remotely monitored gauges to measure water levels and water flow, which will give you an indication of when bridges are experiencing higher flow events. This can be used as a part of a scour plan of action to trigger an off-cycle bridge inspection to ensure the foundation has not been compromised during the flood event. This is especially important if bridges are located in floodplains and subject to an increasing number of flooding events, as is common, for example, in parts of the Upper Midwest.