First, a rather long winded background. I have a customer with an 60" ADS corrugated pipe (in three sections) that runs under a narrow creek crossing. The heaviest load it sees are a few horses. Last year I was called out to work on a washout problem on the outlet side that also received quite a bit of runoff from the sides. I regraded and compacted the bank and installed geo with 20 or so tons of 8x12 rip rap anchored on the banks. The inlet side looked fine at the time and the customer didn't want to mess with it. That said, I set about 2 tons of rock on the banks on inlet side. We had major flooding this spring and the repair didn't budge, but now there's another problem. When the owner had the original pipe installed, they poured a vertical concrete footing at the inlet that starts at the pipe invert and extends 18" below the surface. The runoff found it's way under the concrete and is entering back into the pipe at the first soil tight joint. Probably have the bell installed backwards. My plan is to grade/slope the entrance and install heavy pond liner material anchored with rip rap to stop the inlet leakage problem. I've done it before with no problems several years later. So here's my question. While I'm there I'd like to seal the interior at the joints. I've used WR Meadows mastic and fiberglass tape on exterior joints before, but has anyone used a product on the interior that's worked? Keep in mind that the customer doesn't want to remove and re-bed the pipe.
We have never went inside to fix a joint so I can't help you there. In our area we would dig up the joints wrap with fabric then pour a concrete collar around the joint. Done it quite often and never had any callbacks. I am not sure how old the ADS is but they used those couplings that were held together with zip cords and they did not have o rings in them. The new bell type ADS with o rings is much better.
From what the owner told me they're the old zip style. For reasons that are beyond my understanding...they installed 3-5' sections. :beatsme If I dig it up to collar the joints I might as well replace the pipe so he never has to worry about it again. I'm hoping I can figure something else out for the interior.
I assumed 20 foot sticks not 3 to 5. Maybe he had a bunch of pieces laying around and just bought the couplings:badidea
I'd agree with Landclearer. He used 3 cutoff pieces , probably got them for nothing. The old style didn't have a bell and spigot, you just butted them up and used the coupling to make the connection. The pipe was nearly impossible to make watertight at the joints on new construction so was banned by the local county highway dept from use in their ROW. I'd stop the inlet leakage as you propose and call it good enough