Alchatek Blog

Manhole 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?

What is Curtain Wall Grouting and Why is it Effective?

Curtain wall injection is the process of drilling holes through a structure in a diamond pattern, then injecting the grout into soil on the other side. This procedure creates a curtain wall made of a resin/soil mixture that prevents water from getting back into the structure. It is often required if there are multiple cracks or leaks in a wall. Filling each individual crack may cause you to waste time following the water from crack to crack. Curtain wall grouting allows you to stop multiple leaks at one time and protects the structure on a long term basis.

This procedure was first performed in 1960 on a sewer manhole with a multiple leak problem. As described above, chemical grout was injected through to the outside of the manhole. This created a “positive side seal” (on the side the water is coming from), blocking water from penetrating the joints of the structure.

This method is still used today and is the most effective method for grouting manholes to stop infiltration.  It is effective on structures constructed from a wide variety of materials, including wood, steel, concrete, rubble walls, stone, block and brick.

A Brief Overview of the Curtain Wall Grouting Process

Other Situations Requiring Curtain Wall Grouting

In addition to the “too many leaks” scenario, curtain wall grouting may be required when all cracks cannot be identified in a leaking wall, when previous crack injection has failed, or when a structure has a negative crack injection history. It is also used in masonry, dealing with stone and CMU walls that do not crack inject well.

Material selection is based on various factors such as soils, voids, and moisture conditions. Call us at 404-618-0438 to discuss which material is right for your project.

Want to learn more about this procedure?

Crack Injection

Crack injection has many advantages over other methods.  For example, if you’re sealing a leak in a water tank, you can inject from the outside of the tank. So the tank can remain in service while you repair it. Having to dry a crack, like you do with epoxy resin, is not needed as this material reacts with water. The material also remains flexible at all times.

Crack injections can be applied in both vertical cracks and in horizontal cracks. With vertical cracks, it is imperative to start at the bottom of the crack and work your way up the crack until it is filled. This forces the material up and through the crack and will simultaneously push the water up and out as well. With horizontal cracks, injection can be started at either the left or right end.

The crack injection process is rather simple, but some mis-steps can prove quite costly. For best results, follow the steps below after discussing them in detail with a trained professional...

A Few Words on Acrylate Grouts

Customers who joined us in the Alchemy Polymers era may not be familiar with the acrylate grouts we’re now offering after the merger with with Resiplast US.  Acrylates offer a very wide range of set time control, which makes them good for everything from very tight cracks to gushing leaks (not to mention soil stabilization). One thing to be aware of: all wetted metal equipment parts that acrylates come into contact with must be stainless steel.

Crack Injection Products

If you’re not completely familiar with all or our products, talk to a tech support rep to determine which one is the best for your project. Alchemy-Spetec offers the following crack injection solutions…

Acrylates

AG100, AG200 and AG300

Polyurethanes

PU F400, PU F1000 and AP Seal 500

Want more information on leak seal technologies?

What are Chemical Grouts?

Chemical grouts are water reacted or chemically reacted materials that are designed to shut down active water leaks, stabilize soils and lift slabs in various structures.

Some of these materials are formulated to stop high volume leaks (2000 gpm) or used to stop small leaks in water and waste water treatment tanks.

Geotechnical applications include but are not limited to:

Soil Stabilization, Railroad Ballast Rock Stabilization, Tunnels, Mines, and Seawall Repairs

Why Chemical Grouts?

Chemical grouting serves as the most efficient permanent repair procedure.  It also features little disruption to the local communities as repair times are not extensive. As you all know, leak repairs must be preformed prior to coatings. But why is chemical grouting important? Grouting is the only permanent repair procedure that seals leaks from the positive side (where the water’s coming from) and fills voids in record times.

Hydrophilic & Hydrophobic

It is crucial to understand the basic differences in hydrophilic, hydrophobic, and multiple component chemical grouts. Choosing the correct repair materials for a job is very important.  Let’s dive into the specifics to gather a deeper understanding of the different types of polyurethane grouts.

Hydrophilic

Hydrophilic grouts injected in a confined space shrink more but create a better bond with the substrate. Hydrophilic chemical grouts are resilient and flexible after full cure and allow movement within structures without causing damage to the seal or bond.

Alchemy-Spetec Product Examples: AP Seal 500, PU GT350

Hydrophobic

Hydrophobic grouts injected in a confined space have very little shrinkage, but depend much more on expansion to create their bond with the substrate. Hydrophobic chemical grout has a low viscosity characteristic that permeates loose and non-consolidated soils readily and effectively.

Alchemy-Spetec Product Examples: AP Fill 700, PU F400, PU H100

Multi Component

Multi-component closed cell foam maintains its physical form and is not subject to shrinkage due to wet/dry cycles. It is a rapid curing; self-leveling concrete repair material perfect when minimal down time is required.

Alchemy-Spetec Product Example: AP Lift 475

Cured polyurethane is harmless for the environment and resistant to biological attacks.

Want more informoation on leak seal grouts?

Aging sewer and storm water systems across the country are plagued by infiltration and inflow; especially in areas with high water tables and sandy soils. Over time, compacted soils around catch basins, manholes, and culverts relax and result in deflection of joints and pipe connections. The end result is infiltration of ground water into the storm and waste water systems. This infiltration erodes the soils surrounding below grade drainage structures resulting in sinkholes, settling roadways, and property damage; not to mention the extra cost of treating that uninvited ground water.

The solution is a combination of sealing leaking joints both from within the drainage structures and through point grouting from street level. Expansive polyurethanes such as AP Seal 500 and AP Fill 700 produced by Alchemy-Spetec can be injected directly into pipe and manhole connections where they react with infiltrating water and expand to seal off leaking joints. Additional point grouting from street level fills voids and permeates loose soils. This relieves hydrostatic pressure from the structures and strengthens the ground to support the above roadways and sidewalks.

For below grade structures that a man can safely enter, direct polyurethane injection is the best option. Holes can be drilled directly into the joints or leaking cracks, injection ports are then installed, and AP Seal 500 is directly injected to permanently seal active leaks.

If interior access is limited, point grouting technique can be implemented. This involved driving pipes into the vicinity of the active leaks on the outside of the structures and injecting AP Fill 700.
 

If you would like to discuss either of these products or procedures, please call us at 404-618-0438.

Want more info on infrastructure leak seal and void fill?

In the video clip at the bottom of this post, you'll see polyurethane being used to seal air leaks in new manholes before they were vacuum tested. I was on this "do or die" job as a consultant. Apparently they had been having trouble with the first type of product they tried.

I remember stepping out of my truck and being greeted by our customer with the words, "I don't wanna' hear can't! I don't wanna hear won't! We gotta make this work!" Based on my experience working with polyurthane, I wasn't too worried. It all worked out in the end and the manholes passed the vacuum seal tests. Take a look at the video for an overview of the polyurethane leak seal process...

Want in-depth info on polyurethane leak seal?

Since we haven’t discussed it very much in our blog posts, you may be surprised to learn how much we have to offer on large scale and international projects. In this post I’ll share a list of recent examples to provide a sense of how we can assist in these types of situations.

New York City, New York - Metropolitan Transit Authority

AP Seal 500 leak seal resin was used to repair thousands of feet of cracks through­out new subway tunnels.

Toquepala, Peru - Southern Peru Copper Mine

On this job, we provided the crew with AP Lift 440 rigid polyurethane foam to stabilize loose soil beneath a concrete building. We also provided on-site consulting services.

Guangzhou, China - Guangzhou Highway

We provided AP Lift 475 foam and on-site consultation for soil stabilization and the lifting of a bridge approach slab.

Saskatchewan, Canada – MGM Seed and Grain

AP Lift 440 was used to level 900,000 lbs of interior sunken concrete slabs. We also provided on-site technical consulting. Later, 24” thick slabs supporting grain silos were raised and stabilized.

Tijuana, Mexico – Federal Courthouse

On this project, AP Soil 600 stabilization foam was used to shore up the foundation beneath a sinking multi-story concrete building.

Cincinnati, Ohio – Cincinnati Zoo

In the African Lion Exhibit there was a leak in the concrete moat that surrounds the enclosure. AP Seal 500 was applied to the problem areas to stop the water flow and prevent the unnecessary loss of water.

Conclusion

Regardless of the location or size of your job, we’re here to help. We have extensive experience consulting on locations all over the globe and our products are proven performers on the largest, most challenging projects.

Want more in-depth info on AP products?

Single component, water activated, hydrophobic, low viscosity, closed cell polyurethane injection resin. As the ideal leak seal for cutting off high-flow, underground leaks, AP Fill 700 is a proven polyurethane leak stopper and void filler for all types of concrete structures. Also see our AP Seal 500 Concrete Crack Sealant.

Applications

• Cutting off high flow leaks.
• Concrete void filling for all types of structures.
• Cutting off underground water flows.
• Consolidating loose soil.
• Filling voids under concrete slabs.

Advantages

• Very low viscosity.
• Water impermeable polyurethane resin.
• Adjustable set time – as fast as 20 seconds.
• Injected as a single component.
• Phthalate free available (more environmentally friendly).
• Certified To NSF 61-5 (approved for contact with drinking water).

Check out the AP Fill 700 sample demo! 

Want in-depth info on cutting off high flow leaks?

AP Seal 500 is a single component, low viscosity, flexible hydrophilic polyurethane injection resin. AP Seal 500 is the proven industrial concrete crack sealant. A powerful polyurethane resin that is optimal for sealing hairline cracks, pipe penetrations, joints and larger defects in concrete structures. Also see our AP Fill 700 Concrete Void Filling Resin.

Applications

• Sealing cracks in concrete structures through pressure injection.
• Sealing hairline cracks, expansion joints, wide cracks, pipe joints, pipe penetrations.
• Saturating dry oakum to create a flexible gasket for sealing pipe penetrations, joints and larger defects in concrete structures.

Advantages

• Polyurethane injection with no catalyst required.
• Tenacious bond to wet concrete.
• High elongation polyurethane concrete crack sealant.
• Thin enough to penetrate tight cracks.
• Moderately hydrophilic.
• Phthalate free (more environmentally friendly).
• Certified To NSF 61-5 (approved for contact with drinking water).

Watch the AP Seal 500 sample demo! 

Want in-depth info on sealing leaks?

We're happy to announce that Alchemy Polymers has been profiled in a feature article on SprayFoamInsider.com. This is a good match, since we get a lot of interest from spray foam professionals looking to expand their skill set into slab lifting and other forms of concrete repair. After doing a fair amount of background research, Editor Jay Davidson has written an overview of our company's mission and the solutions we offer for critical concrete infrastructure issues.

The article opens as follows...

Alchemy Polymers, LLC is comprised of combat veterans when it comes to battling the elements and saving valuable infrastructures with their polyurethane resins. Contractors can even “sign up” for “boot camp” training to learn the valuable secrets of polyurethane applications from those who have literally been in the trenches. Their winning polymer injection solutions have a highly successful track record for repairing and restoring sea walls, retaining walls, tunnels, bridges, dams, concrete slabs, highways, pipelines, railways, sink holes, homes, buildings, subways and other below ground structures.

You can read more in Jay Davidson's piece Alchemy Polymers, LLC is Winning the Battle to Restore Infrastructures.  Needless to say, we're happy to see Alchemy Polymers featured on SprayFoamInsider.com.

Want additional in-depth info on Alchemy Polymers products and procedures?