Alchatek Blog

In this post we will discuss the many advantages of GT350, as we follow through with the overview of the Alchemy-Spetec product line.

What is GT350?

GT350 is an MDI based hydrophilic, one-component flexible polyurethane injection resin for waterproofing.

What are the advantages & applications?

GT350 is used for shutting off water leaks in concrete, brick work and sewers where movement and settlement may occur. It can also be used for water cut off in walls. In addition, GT350 can be injected behind sheet piles and secant piles for curtain wall grout repairs. Last but not least, it can be used in tunnel joint segments and open wall joints with highly active water leaks.

Additional Information

Cured polyurethane is harmless for the environment and highly flexible, making it resistant to biological decay. It is ideally suited for structures where a high degree of settlement and movement can occur.

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In the previous post we went over the properties of AG100. Today we will discuss the properties of AG200, which is in the same family. (If you haven’t already, be sure to check out my previous blog post on AG100.)

What is AG200?

AG200 is a three-component, water-swelling hydrogel based on acrylate or methacrylate that hardens to an elastic product.

What are the advantages & applications?

AG200 is known for its low blending viscosity, which can be compared to the consistency of water. This acrylate is mainly used for curtain wall grouting. In addition, it can also be used to redirect ground water, stabilize soils prior to excavation, and inject cracks. The set times can be controlled by varying the amounts of catalyst on the resin side and salt on the water side.

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In this post, I’ll continue my overview of the Alchemy-Spetec product line with a profile of H100. If you haven’t already, be sure to check out my previous articles on F400 and F1000.

What is H100?

H100 is a one-component, closed cell, water activated, semi-flexible polyurethane leak seal injection resin.  Its low viscosity and hydrophobic properties make it ideal for both soil stabilization and cutting off large water leaks.

What are the uses for H100?

There are a plethora of applications for H100, primarily cutting off high flow leaks and soil stabilization. Some specific uses include cutting off sewer water leaks and soil stabilization around sewer structures. Other uses include water cut-off of leaks in foundations such as diaphragm walls, piling sheets and secant piles. H100 is also good for stabilization and water cut-off of large cracks, voids and gravel layers. H100 has been used to stabilize soil and anchors in porous geology along with crack and gravel layer injections in concrete structures. In addition, it's is an ideal resin for probe grouting below grade pipes and manhole injections. Last but not least, injections in combination with cement-based grout work very well with pre and post injections in mines, tunnels, pipe jacking, drill & blast and TBM applications.

Advantages of H100

The one component, closed-cell structure allows the cured polyurethane resin to seal large water leaks in cracks and joints permanently. With adjustment of the percentage of H100 ACC accelerator it is also possible to alter the reaction times. Once H100 is cured, it exhibits high strength and good chemical resistance. This in turn makes it harmless to the environment and resistant to biological attacks. Not to mention it is also WQA certified to come in contact with drinking water.

Alchemy-Spetec no longer carries this product.  Click here to read about our current Leak Seal product line. 

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There are many polyurethane resins that are used to treat water leaks. Today we will review F400. I have recently joined Alchemy-Spetec as Western Regional Manager, and I'm studying up on the product line. I thought it would be beneficial to share what I'm learning about the Spetec line with our blog readers, as many who joined us in the Alchemy Polymers era may be new to these products as well.

What is F400?

F400 is a one-component polyurethane leak seal injection resin that is designed to shut off water leaks. It's a closed cell, flexible, hydrophobic, low viscosity resin. It's also solvent and phthalate free.

What is F400 used for?

F400 is used to shut off water leaks in concrete, brickwork and sewers where movement and settlement may occur. It also makes a great water cut-off for leaks in foundations such as
diaphragm walls, piling sheets and secant piles. In addition, you'll find it helpful for sealing water-carrying cracks and joints in tunnel segments. Not to mention cuurtain grouting behind tunnel, concrete, brickwork and sewer walls. It's also great for injection of water cut-off membranes and liners in tunnels.

Want an in-depth overview of Alchemy-Spetec leak seal solutions and procedures?

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

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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.

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