Alchemy-Spetec Blog

Crack Injection and Curtain Wall Grouting – Part 4

Posted by Charlie Lerman on Mar 20, 2017 12:10:22 PM

Steps to (2).pngManhole Leak Repair

Leaking manholes can cause unnecessary damage to the environment and can be costly if left untreated. Water leaks can create voids that can lead to sink holes, roadway collapses and system failures. Chemical Grouting is a low cost, durable repair method for manholes which can often prolong the life of the structure.

Injection Methods for Manhole Repair

Brick Manholes

  • Drill to the outside of the manhole and into the soil through the brick.
  • Repair all pipe penetrations, and have oakum ready to help plug leaks.
  • Start injection of material at the bottom and work your way up.

Precast Manholes

  • Repair all pipe penetration and apply oakum rings if too wide.
  • Drill injection holes into the manhole rings at the four main clock positions (12-3-6-9).
  • Start injecting material from the bottom up.

Storm Culvert Leak Repair

Storm culverts transport large volumes of water. When they leak this allows exterior soils to be carried in the storm culvert allowing sink holes above. Chemical grouting these structures is a non–excavation repair, which will seal joints and leaks and stabilize soils. Unlike pumping concrete, chemical grouts add little to no weight to surrounding soils. Injection of storm culverts can be achieved by manned entry or via probe grouting from above when access is not considered feasible.

Injection Methods for Culvert Repair

Manned Entry Method

  • All joints need to be identified and inspected for any possible concrete repair that may need to be performed prior to injection process.
  • Wide joints should be packed using oakum rope and chemical grout to minimize waste and contain injection grout in joint, once prepared injection can be performed.

Probe Grouting Method

  • Map off leaks using a CCTV camera.
  • Measure out and mark locations on the street or soil above.
  • Drill holes though street or soil above at each location.
  • Insert injection pipe to a depth of one foot below bottom of repair point.
  • Start injecting a rate of 1 gallon per foot stopping at the top of the pipe.

It is important to remember that a leak is a round-the-clock problem. A small leak can eventually lead way to a larger leak, which can be catastrophic if left untreated. The longer you wait before repairs, the more expensive it becomes.

Want more information on leak seal repairs?

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Topics: All Posts, Seal Leaks