Regarding water infiltration in utility vaults, precast joints often serve as weak links. Conventional methods like cementitious grouting offer temporary solutions but often fail to withstand structural movements or shifting over time, resulting in a reoccurrence of leaks.

Repairing Precast Joint Leaks with Spetec PUR GT350

Utility vaults are constructed from precast concrete sections that are joined together. The connections between these concrete sections are called precast joints. Over time, precast joints may develop small gaps caused by things like soil movement or temperature changes. These gaps allow water to leak into the utility vault.

An effective solution is using a combination of Spetec PUR GT350 and Spetec Oakum. Spetec PUR GT350 is a flexible polyurethane grout that can accommodate movements between sections of precast concrete. Spetec Oakum is an oil-free dry jute rope that, when used in conjunction with the grout, helps seal large and irregular-shaped defects.

Installation Steps

1. Clean the surfaces where you plan to apply the Oakum. Moistening the surfaces can enhance the reaction with the resin.
2. Cut the Oakum into appropriate lengths.
3. Saturate the Oakum with Spetec PUR GT380 resin in a clean container, allowing time for the resin to soak in.
4. Using gloves, pull a section of the saturated Oakum through a loose set to remove excess resin.
5. Dip the Oakum in a pail of water to initiate the resin's expansion.
6. Tightly pack the Oakum into the leaking precast joint using an appropriate tool, such as a screwdriver or wooden dowel.
7. If needed, inject additional resin directly through the Oakum via a grout needle or by drilling holes into the concrete behind it.
8. Allow the material to cure overnight before trimming any excess foam.

Repairing Pipe Penetration Leaks with Spetec PUR F400

Pipes for utility lines pass through openings in the walls of utility vaults. These openings are called pipe penetrations. Concrete and/or sealant around the pipe penetrations can break down over time. The vault walls may also shift a little bit. Both of these issues can lead to gaps around the pipe penetrations, allowing water to leak into the vault.

Qualified contractors can use Spetec PUR F400 combined with Spetec Oakum to achieve long-lasting results.

Installation Steps

1. Soak Spetec Oakum in Spetec PUR F400 polyurethane grout, and then quickly submerge it in water.
2. Immediately pack the soaked Oakum around the pipe sitting in the sleeve, allowing it to harden into a tightly sealed gasket.
3. If further sealing is required, use an injection needle to fill the area behind the Oakum with more chemical grout.

The longevity of this approach is remarkable, offering durability that could last up to 50 years.

Key Takeaways

• Polyurethane grouts like Spetec PUR GT350 and Spetec PUR F400 offer superior performance and durability for sealing leaks in utility vaults.
• When used in conjunction with Oakum, these grouts provide effective solutions for addressing leaks at precast joints and pipe penetrations.
• Following the appropriate installation or repair steps ensures that the leak-sealing measures will be long-lasting, potentially offering up to 50 years of durability.

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