One of the biggest challenges of doing bridge and highway structure rehabilitation and repair is getting the work done while minimizing the impact on traffic. Here’s how one crew used smart bridge maintenance techniques to prevent a traffic nightmare while completing a concrete deck repair.
THE PROJECT: New Jersey Turnpike bridge deck rehabilitation
When doing new concrete bridge construction, a concrete boom pump truck is often positioned on the ground, with the boom reaching up and over the top of the bridge deck. However, that’s not an option for doing a bridge deck repair because regulations prohibit booming over traffic on an active roadway.
For this concrete bridge deck repair project on an elevated section of a New Jersey highway, the contractor chose to position a concrete boom pump truck underneath the bridge and thread the boom through a hole in the concrete bridge. Then the boom was attached to a 400 foot pipeline on the concrete deck to pour the material.
The equipment: Putzmeister BSF 32.16H truck-mounted concrete boom pump
To pump concrete for the bridge deck repair from underneath, the contractor needed a concrete boom pump truck with a long enough reach to get the boom up through the hole in the bridge.
Many times, a concrete deck repair like this would be done with a high pressure line pump, concrete supply trucks, and long lengths of pipeline positioned on top of the bridge. However, doing that has quite a few disadvantages:
- Putting all the equipment on the bridge takes up more space on the roadway and setup usually requires the entire bridge (or at least one direction of traffic) to be closed. Whenever possible, it’s preferable to keep some of the bridge open during the repair to prevent traffic problems.
- Pouring with a boom pump truck from underneath can accomplish a longer pour with a shorter length of pipeline. In this case, the contractor could pour in two directions starting from the same hole, so 800 feet of concrete deck could be poured with 400 feet of pipe.
Why is the pipe length important? First of all, it takes more manpower (and therefore more cost) to manage a longer pipeline and clean it out. Also, the longer the pipeline, the more concrete is wasted after each pour is complete. For each 200 feet of pipe, a yard of concrete must be flushed out and disposed of. So if you use 1000 feet of pipe, that’s 5 yards of concrete to clean out and cart away. It’s always better to use a shorter length of pipe when possible.
That’s why this concrete bridge deck repair technique of pouring from underneath the bridge is so smart: it saves the contractor money and headaches, while also saving local drivers from traffic headaches!
Obviously, for this concrete bridge construction technique to work, you need access to the underside of the bridge. So if there’s water, railroad tracks, unstable ground conditions, or a steep slope under the bridge, you may have to stick with using a high-pressure line pump on top of the deck.
Steps for doing concrete bridge deck repair with a boom pump underneath:
- Set up a concrete boom pump truck underneath the bridge.
- Close down the lane(s) for bridge deck repair, and make a hole at the center of the pour location for the boom to come through from underneath the bridge.
- Set up pipeline on the bridge deck to be prepared, starting at the location of the hole and extending outward. The pipeline should be long enough the reach the length of roadway you plan to complete with a single pour.
- Place the end of the boom through the hole and attach to the hose and pipeline.
- Pour from the furthest point back to the hole.
- The next day, set up your hose and pipeline going in the other direction from the hole, and complete another pour before you need to move the boom pump truck.
Here at Alexander Wagner Company, we have been providing concrete pumping equipment, supplies and service to contractors in the New York metro area for decades. We’re happy to answer your questions and share our expertise. Feel free to reach out to us anytime!