Alchatek Blog

How Polyurethane Grout Injection Works for Stormwater Infiltration Prevention

During a period of heavy flooding, stormwater systems become more susceptible to erosion and the infiltration of polluted water. For municipalities, infiltration of polluted stormwater means costly treatment of water and infrastructure repairs to damaged pipes.

The Stormwater Infiltration Issue

• Ground water rising and falling puts hydrostatic pressure on pipe and manhole joints causing them to fail.
• Water flowing in and around catch basins and roadways causes soil to erode.
• Water flowing into failed joints erodes soil from around the infrastructure causing potholes, cave-ins, and loss of structural integrity of the storm water system. Pipes can become misaligned causing much more expansive problems. 

The Solution: Polyurethane Grout Injection

• Point grouting is a method of driving injection pipes to the points of failure and injecting a resin such as Spetec PUR H200.
• The resin expands and cures quickly to seal off the leaks and fill voids in the soil.

The Favorable Outcome

• Sealing the joints prevents further soil erosion.
• Filling the voids with a resin like Spetec PUR H200 reduces the hydrostatic pressure on the joints.
• The resin also permeates the soil and increases the load bearing capacity which can prevent future misalignment of the pipes.

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Alchemy-Spetec is already known for providing the most powerful polymers and painless procedures contractors need to achieve the rapid results their projects demand.

However, on construction projects of almost any scope and size, ensuring the safety of public drinking water is also mission-critical. That's why the following Alchemy-Spetec' polyurethane resin products have received the official NSF seal of approval for contact with drinking water: 

AP Lift 430

AP Lift 475

AP Soil 600

AP Fill 700

Spetec PUR H100

Spetec PUR H200

Spetec PUR F400

Spetec PUR GT500

Spetec PUR HighFoamer

Spetec AG200

This single designation ensures compliance with the Safe Water Drinking Act (SDWA) and guarantees peace of mind for in-the-field stakeholders on construction projects of almost any scope and size.

The SDWA helps ensure the water we drink, bathe in, cook with, and use in myriad other ways in daily life is safe for consumption. The federal law was put in place to maintain public health standards for drinking water systems. It defines what is considered a contaminant – both man-made and naturally occurring; and outlines the agencies responsible for regulating, monitoring, and enforcing adherence to the law, primarily the Environmental Protection Agency.

The SDWA gives the EPA latitude to impose criminal and civil penalties on industries not in compliance. In 2014 enforcement efforts policing clean water netted $163 million in penalties and fines, 155 combined years of incarceration for sentenced defendants, and $16 million in court-ordered project clean-ups.

Because so many of those defined contaminants are pertinent to even the most basic construction projects – turbidity from soil runoff, leaching from PVC pipes, potentially harmful and corrosive chemicals, and more – understanding and adhering to the law is particularly important for industry stakeholders. Contractors and engineers must be able to confidently choose vendors whose products and services won’t become the source or cause of drinking water contamination either in the short or long-term. NSF certification offers assurance that such problems won’t occur or will, at a minimum, be addressed.

“NSF, an independent, private, not-for-profit, third-party certification organization founded in 1944, has developed numerous health-based certification programs and consensus standards including those that relate to drinking water,” reads an NSF compliance brief. “The purpose of its certification program is to promote public health and enrich the quality of life. Through its Council of Public Health and Health Advisory Board, which includes EPA health professionals, it obtains guidance in developing and maintaining programs and standards. NSF also partners with code councils to ensure ongoing compliance.”

The products Alchemy-Spetec offers that can help net the most reliable and cost-effective results for contractors. NSF-certified products and materials are evaluated and lab-tested, and production facilities such as our own are inspected and annually audited for re-testing to maintain certification.

Alchemy-Spetec voluntarily undergoing such a rigorous certification process is invaluable to customers because it provides assurance that, at the end of the day, our arsenal of products are not only the top-performers in the market, but also protectors of the environment.  Powerful polymers, painless procedures, rapid results!

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Concrete restoration and waterproofing contractors see so many different kinds of leaks out in the field that categorizing them into basic groups is not an easy task.  However, that’s what we’re going to try and do.  The reason for this is to demonstrate how just two products in your arsenal can accomplish 90% of leak sealing tasks.

Alchemy-Spetec manufactures a range of polyurethane resins for Sealing Leaks, Stabilizing Soil, and Lifting Slabs.  Today we’ll focus on Spetec PUR GT500 and Spetec PUR H200 to demonstrate the versatility and scope of leak sealing that can be accomplished with these two products.  To be clear, the leaks we are addressing today are leaks through concrete, below grade structures, and through the soil.

Leaks through concrete are generally going to be through cracks, joints, and honeycomb (areas in poured concrete of mainly course aggregate with voids in between).  Depending on water volume and pressure, and the size of the joint or crack, you are going to encounter weeping leaks, steady leaks, and gushing leaks.  And of course there are also the “sometimes it leaks” types of situations.  All of these can be stopped permanently with Spetec PUR GT500, Spetec PUR H200, or a combination of both.

Spetec PUR GT500

This flexible hydrophilic injection resin is very low in viscosity and is excellent for injecting into hairline cracks and standard cracks and joints up to 3/8” wide.  It bonds aggressively to concrete and handles any movement within the crack because of its flexibility.  Spetec PUR GT500 is a single component resin designed to penetrate deep into the cracks, react with the water, and seal the leaks.  Its reaction time is slowed down somewhat in order to allow it to migrate throughout the crack.  On larger cracks which are actively leaking, a little oakum or backer rod can be wedged into the crack to prevent the resin from running out before it sets up.

Spetec PUR H200

Because the rapid expansive properties of this semi-rigid hydrophobic resin make it great for filling voids, it’s also excellent for shutting down strong and gushing leaks up to thousands of gallons per minute.  The low viscosity of this product allows it to be injected into hairline and smaller cracks as well, but it is mainly used for stopping the big ones.  Use Spetec PUR H200 with an accelerator to adjust the set time according the conditions of the leak. 

Spetec PUR H200 is also an excellent product for the process known as “curtain grouting”.  For instance, earthen dams and ponds often have water migrating through the soil creating voids, water loss, and potential failure.  Grouting into the soil in a grid pattern can seal off this water migration.  The resin expands into the ground and penetrates through the fines, and then bonds well with the surrounding earth.

Spetec PUR GT500 & Spetec PUR H200

Sometimes a leak requires a combination of both products.  Here is an example from an actual job:

There was a below grade utility vault that housed valves for two sewer force mains.  There were 24” and 18” ductile iron pipes penetrating the vault to connect to the valves.  Around the pipe penetrations, a previous contractor had used clay and mortar to try and seal it, but the water table was about 10’ above the penetrations and it had blown out the seals.  The entire vault (14’L x 12’W x 20’H) would fill up with water within a few hours.

Once again, these basic products were all that was needed to stop the leak.  The new contractor punched holes into the side of the vault near the pipe penetrations and installed injection ports.  Spetec PUR H200 with the standard catalyst was pumped through the ports and the hydrostatic pressure of the water forced the reacting resin back through the pipe penetrations slowing the leak and then quickly sealing it off.  Because there is some vibration in a pipe, Spetec PUR GT500 was then injected in a circle around the penetration creating a flexible seal and shutting down any trickles.  In this case the water table was so high that as the polyurethane expanded and reacted with the water, it literally travelled up the exterior of the vault and came in through some unseen cracks and poorly sealed joints, sealing those issues off as well.

It's is easy to go into a product catalog and become overwhelmed by the array of choices.  But don’t over think it!  Two products, or a combination of both, may be all you need to get the job done. 

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Alchemy-Spetec products will now officially be promoted under the Leak Seal and Geotech lines.  As holds true with most mergers (Alchemy Polymers and Spetec formed Alchemy-Spetec in 2017), the integration of products and services can take time.  This rebrand will be reflected in two separate product catalogs.  One for Leak Seal products and one for Geotech products. We are confident that the two-catalog offering is the best solution for our partners and customers. 

Both product types are now easily discernible by the Spetec or AP nomenclature in which Spetec represents Leak Seal, and AP represents Geotech. 

The Geotech line encompasses all two-part rigid polyurethanes used for void filling, slab lifting, permeation grouting, and soil stabilization; as well as acrylic grout used for permeation grouting, and all associated pumping equipment and accessories. Due to the technical support requirements of geotechnical applications in terms of equipment use, accessory setup, and application technique, this line will remain a direct sale to contractors performing slab lifting and soil modification applications.  

Conversely, the Leak Seal line remains a distributor sale through our continued support of distribution partners.  The Leak Seal line encompasses all water-activated grouts, acrylic grouts, waterstop products, mechanical packers and ports, and all associated dispensing equipment.   Since structural repair products are also sold through distribution, they are included in the Leak Seal catalog.

If you have any questions about the Alchemy-Spetec Leak Seal or Geotech product lines, please contact Jim Spiegel at jspiegel@alchemy-spetec.com for further assistance. 

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As we move toward a more clear definition of the Spetec and AP product lines representing our Leak Seal and Geotech product lines respectively, we're making a couple of product branding adjustments effective this week (or as soon as current stock is depleted).

AP Seal 500 will be rebranded as Spetec PUR GT500.  We are also introducing a water-activated semi-rigid polyurethane foam injection resin to the leak seal line which will be known as Spetec PUR H200.  Both of these products feature NSF/ANSI 61-5 approval for contact with drinking water. 

Spetec PUR GT500 is the exact same AP Seal 500 product you know and love, but rebranded to fit in with the Spetec leak seal product line.  This single component, low viscosity, flexible hydrophilic polyurethane injection resin is optimal for sealing hairline cracks, pipe penetrations, and joints in concrete structures.

Spetec PUR H200 is a single component, water activated, hydrophobic, low viscosity, closed cell polyurethane injection resin. Because it expands twice as much and (with the right catalyst) sets up 2.5 times as fast as the Spetec PUR H100, it's an ideal leak seal solution for quickly cutting off high-flow, underground leaks.

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A few years ago, we were asked to do a product demonstration for the Utilities division of Orange County, FL (which includes Orlando). Truthfully, I have dealt with Orange County since the mid 1990’s. They have a crew that does infiltration grouting among other things.

We were supposed to demonstrate our product on a fairly slow leak in a manhole. Not by design, but this was the leak they were scheduled to fix in the time frame we had scheduled the demo. Originally, they asked me to bring 5 pails of AP Fill 700. I also brought both our slow and our fast catalyst.

When I showed up in the morning, they told me they found a different leak which was a gusher. They asked if I had about 10 pails. I told them I only brought five. They said, “we’ll try your stuff first, then we'll finish up the leak with the current product we are using.”

We showed up to the jobsite and Tom, who has been doing leak seal for many years, said basically the same thing. “That’s all you brought?” Tom was quite a skeptic - at first.

They popped the lid off of the manhole and revealed a gusher at the bottom – about 12 feet down from the roadway and leaking probably 15 gallons a minute. The county performs what is called “Point Grouting”, which is a process where a pipe is driven from the surface down to the area near the leak. Polyurethane grout is pumped through the pipe to fill up the void and seal the leak. Tom expected to use between five and ten pails of grout.

We catalyzed the resin with a maximum dose of our fast catalyst. Tom started pumping. I had my fingers crossed hoping that he had the injection pipe in the right location. He did. The foam started coming out of the defect in the bottom of the manhole within 30 seconds. By the time he had pumped half of a 5 gallon pail, the leak was completely sealed. Tom went from a skeptic to a believer in less than five minutes. “I want some more of that, boss!” he said to Paul Morrisson – Utilities Supervisor.

Paul summed it up best – “Based on our extensive prior experience, we expected to use five to ten pails to stop this leak. With AP Fill 700 we were able to do the job with 1/10th that amount of material. Alchemy-Spetec product will save our crews a lot of time and labor and save the taxpayers of Orange County a lot of money.”

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Welcome to the 3rd and final part of my blog post series “Sealing Leaks on Remote Job Sites”. In Part 1 and Part 2 of this series, I described a remote leak seal job I assisted a customer with and the unique preparations it required. So to pick up the story where I left off - there we were, in the jungle, about a mile from our trucks. Of course we were doing our best to deal with the August heat and humidity. At least we had poison ivy, ticks, and yellow jackets to keep us company as we tackled these pipe penetration leaks on the aerial manholes.

As I mentioned, we removed as much of the old mortar from the pipe penetrations as we could. We also drilled our port holes at this time, about 5 inches apart and all the way around the pipe penetration. The port holes were drilled at a 45º angle, and located so that the injected resin would hit the pipe about midway through the penetration. Then we flushed out the areas and port holes with clean water.

Now it was time to seal it. We soaked oakum in the polyurethane and then gave it a quick dip in a bucket of water to get it activated. Then we packed it into the pipe penetration as deep as we could get and all the way around the pipe completely to form a back seal. Then we did it again forming another seal all the way around the pipe penetration but this time towards the outside wall of the manhole. Finally we injected the urethane into the ports working our way from the bottom to the top, completely around the pipe penetration.

For this application, AP Seal 500 was the right choice. It reacts when contacted by water, it's flexible, and it bonds tenaciously to concrete. Plus, its low viscosity allows it to get into tight cracks and voids to seal off leaks. If there is water present in the cracks, it can be injected straight. We actually injected it with water using a two chambered cartridge and static mixer. One chamber held the resin and the other was filled with water just prior to injecting. The reason we did this was because we were working during the middle of the day when sewer flow was the lowest. There was no leaking water present in the penetrations so we had to provide our own. Injecting with the water provided the “kick” to make the urethane foam expand and form an excellent seal between the front and back oakum gaskets we created.

Although it was not in the contract, we couldn't ignore the other small leaks through the manhole walls. Plus we wanted to help the county in return for their clearing the footpath to the manholes. These particular leaks were below the pipe penetrations and were constantly seeping sewage water. There were literally hundreds of yellow jackets swarming on the wet manhole face but they didn't bother us. To repair these leaks we drilled port holes that would intersect the cracks at an angle. As always, we flushed out the holes with clean water. As an experiment, we only put in a couple ports and then started injecting the same polyurethane; this time without additional water as there was already water present in the cracks. Sure enough, the low viscosity resin traveled throughout the cracks as it was injected and sealed off the areas where water was working its way through.

When we were finished, the manholes were completely dried out and there was no longer sewage leaking into the sandy soils beside the creek. It always feels good to get a job done when there's the added benefit of doing something to protect the environment. It also feels good when a project goes smoothly because you took the extra time to visualize it, plan the work, and work the plan.

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In Part 1 of this series, I laid out the challenges my customer's crew faced repairing pipe penetrations on aerial manholes in a very remote area. The repairs aren't that hard, but when you have to carry all of your materials and gear across creeks and down gullies, you have to work smart.

Previously, I indicated how we took the time to do a thorough site evaluation. Then we created a plan and a master list of what we would need; knowing we would have to carry everything in and out. We decided to repair the penetrations with a combination of polyurethane soaked oakum as a packing material and a low viscosity hydrophilic polyurethane that we would inject.

These particular pipe penetrations had originally been sealed with mortar and the manholes were of brick construction. Since they were also quite old, the leaks were not very hard to find. In fact there were gaps up to one inch in width between some of the pipes and the penetration holes. The mortar had just crumbled away. In addition to the penetration leaks, there were also several leaks through the walls of the manholes. A skim coat of mortar had been applied to the outside surface, covering the bricks. But now waste water and sewage was finding its way through the many brick seams and joints, and the crumbling mortar too.

I'll spare you some of the things we used that are common to all of our jobs; items such as buckets, mechanical ports, drill bits, gloves, safety glasses, etc. Items of note that did come in handy on this remote project were as follows:

1. Plastic sheeting to cover our gear when it rained and ponchos for ourselves.
2. A hand powered, 2-component cartridge gun. We were prepared to use a small CO² tank to power our pneumatic gun but it turns out we did not need much pressure to inject the resin.
3. Battery powered Ridgid brand hammer drill with 3 extra batteries. It took one battery to drill port holes 360º around each 22” diameter penetration. During lunch we would take the batteries to the truck and recharge them with our generator.
4. We brought a light weight plastic chemical sprayer. We were able to fill it with water from the creek and it generated enough pressure to flush our drill holes and the areas around the penetrations where we dug out the old mortar.
5. Light weight dry oakum. This was great for sealing the large gaps. Dry oakum can be soaked in polyurethane, packed into joints and cracks, and activated with water. It will swell up and become like a flexible gasket.
6. Bug spray and a sense of humor.

In my next and final installment on this subject, I'll go into detail about how we actually completed the repair and saved the planet. To wrap up this one, I would just say that it pays to think things through and be creative. There are usually several ways to get the job done; in our case we had to get the job done without exhausting ourselves getting there and back. We brought lightweight cartridges and oakum, battery powered hammer drills, and simple plastic sheeting to protect from the elements. These things took the place of pumps, compressors, electrical power, and shelter.

There's one last thing I recommend looking in to: Even though this was a job that could only be accomplished on foot, the owner of the pipeline was the county and they have to maintain a path so they can walk the line, make repairs, and cut up trees that fall across the pipes connecting the manholes. For this job we worked hand in hand with the county, walked the line with them, and got them to send in their crew to clear out the path anew for us. Our repairs repaid them for their free help.

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Hopefully these tips on overcoming obstacles on remote job sites will be of assistance on your next out-of-the-way project. At one point I had the opportunity to advise a customer who was repairing pipe penetrations of aerial manholes along a drainage basin in SW Atlanta. Aerial manholes are typically found in low spots next to creeks and rivers. They are usually connected by steel or ductile iron sewer pipes that are above ground and thus, so are the penetrations.

The conditions of the job site were unique as there was no access to the individual manholes except by foot. This particular project covered a winding 1-1/2 miles through ravines and involved several crossings of the stream. The goal was to seal the 18” and 22” pipe penetrations that were leaking raw sewage down the faces of the manholes located along the creek. In this report I will let you know how we got started in preparation for the unique set of challenges this project presented.

First of all, a thorough evaluation of a remote job site must be undertaken. This should be done prior to submitting a bid, but it should also be done again with an extra set of eyes prior to commencing the work. Then create a plan and a master list of what you will need:

1. Consider all of the possibilities of how to mobilize; where can you set up the nearest base camp for your trucks and supplies.
2. What tools or alternative tools can be used to get the job done; realize there are certain conveniences you're not going to have, like generators and air compressors, and find alternative methods.
3. Select the right Leak Seal materials to get the job done such as AP Seal 500, AP Fill 700 and activated oakum.
4. Prepare a good safety plan. We experienced rugged terrain, snakes, bees, ticks, extreme heat, downpours, and lightning. Think about how to protect your people, your materials, and your gear. Make sure to have first aid and hydration available on site and at the base camp.
5. Have a communication plan – make sure you have reception between the job site and the base camp. If cell phones don't work then bring walkie talkies. Have someone at the base camp to watch gear, to get supplies when necessary, and to be available for help in case of an emergency.
6. Be prepared to clean up your job site with respect for the environment. If you haul it in, be ready to haul it out.
7. Last of all, choose the right people for your crew. Think carefully, because these kinds of jobs are not for timid or easily discouraged personality types.

In my next post I will go into detail on the procedures and tools we used to stop the leaks through a combination of polyurethane injection and activated oakum.

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Water leaking through concrete can lead to structural failures, sinkholes, and other costly types of property damage. For property owners, it is important to be aware of potential problem areas in your facility, factory, or residence. For concrete restoration and waterproofing contractors, it is important for your business to know where to look for leak sealing opportunities.

So where are the areas that contractors and property owners need to be looking? Here we have broken it down into two broad categories: Commercial / Industrial / Municipal and then of course, Residential.

Commercial / Industrial / Municipal

• Tanks: Water and Wastewater Treatment Plants, Aquariums
• Infrastructure: Concrete Pipe, Manholes, Pipe Penetrations, Lift Stations, Pumps Stations, Utility Vaults
• Industrial Plants: Machinery Pits, Containment Structures, Retaining Walls, Slab Joints
• Tunnels: Tunnel Segments, Retaining Walls, Headwalls and Wing Walls
• Commercial: Floors, Parking Structures, Elevator Pits, Basements
• Specialized arenas for sealing leaks in Mines, Dams, and Power Plants.

Residential

• Single Family: Basements, Foundation Walls, Swimming Pools, Fountains, Seawalls, Retaining Walls
• Multi Family: Elevator Pits, Parking Garages, Seawalls, Pools, Basements
• Farms: Silos and Tanks, Earthen Dams, Manmade Ponds

Alchemy-Spetec manufactures an effective range of polyurethanes designed to seal leaks for all of the above issues. We also strive to continually educate the market. 

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