The driveway at our new house crosses over a creek, which requires 3 concrete culverts, about 16' long and 30" in diameter. The culverts are each made of two pipes with a joint in the middle. Without going into details, a lot of care was taken in construction, including gravel under the culverts and more. However, the pipes settled, so the joints have lowered a bit. I talked with the county engineers and the designer and everyone felt the best solution was to grout the cracks this created in the pipes.
I still have a small amount of water leaking from the pipes. (I suspect there are microfissures between the grouting and the culverts, since we've tried tracing the leaks without success, even with tracer dye.) We've worked out how to handle the drainage. I would like to find a sealant I can use on these joints where the grouting has been done and see if it's possible to stop the leaking with some kind of sealant.
There are a few factors to take into account:
- This is in a creek, so any sealant will be under running water all the time. (I found one product at a chain store, but under the Q&A for the product, the makers said it shouldn't be under water all the time.)
- This is in an area officially designated as wetlands. I can dam up a pipe and pump it dry before and while working on it. I can keep it blocked for a few days after if I need time for any sealant to set.
- Since this is in the wetlands, and feeds into a local lake, I need to be sure that after any sealant is dry, I won't have any issue with chemicals being washed downstream from the work where it can kill fish or crawfish or anything else. Of course, I also have to make sure it doesn't put anything into the water supply that is bad and can be traced back to me.
- While the normal flow through the pipes is not too heavy, the structure is designed to easily withstand a 100 year flood and when we have storms, the flow increases significantly.