Conduit seals at manholes

QUESTION
Anyone know of a paper or article that summarizes various conduit seals for waterproofing and water pressure? Looking at hydrophilic foams but don’t have any experience with them.

REPLIES

rcwilson
Conduits into manholes leak water. My experience is that it is more effective, but costly, to put in sump pumps than to waterstop the conduits. Any method to stop he water intrusion seems to fail.

That said, Roxtec also makes a retrofit product that looks like it will work to seal conduit entries after cables are installed. It is custom manufactured. Raychem (Tyco?) had a C02-filled, adhesive-coated, mylar balloon system that wrapped around the cables and expanded to seal when inflated with CO2 that seemed to work on one project.

Our problems were usually leaking manholes and leaking ducts with the field personnel looking for easy cheap solutions. Duct seal and other putty type compounds could not withstand the hydraulic pressure. We could hear them popping out as the rains came.

SOURCE
https://www.eng-tips.com/viewthread.cfm?qid=336693
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