When an old brick retaining wall in downtown Greenville collapsed and crushed three cars, Wurster Engineering and Construction was called in to stabilize the embankment and install a new wall system. Based out of Greenville, SC, Wurster is a geotechnical engineering and construction firm that specializes in soil and embankment stabilization. The project would require removal of the remaining brick wall, soil nailing the embankment, installing a shotcrete wall, and then tying in a new brick wall to the stabilized embankment.

However, one problem remained. There was one area where there was a portion of the brick wall that needed removal, but the temporary concrete retaining wall to protect the property had been poured on a bed of gravel that was being held in place by the remaining brick. The gravel under the temporary wall footing was contained by the remaining brick, which when removed would cause all of the gravel to run out. This section was about 30-35’ long, 2’ high, and 4-5’ deep from the face of the wall to the back.

Powerful Polymer

In order to solve this issue, Wurster Engineering and Construction selected AP Fill 720 to permeate the gravel and hold it in place while the brick was removed. This polyurethane resin was the ideal choice because of its ability to thoroughly permeate the gravel, lock it all together, and then cure to a high compressive strength. With the gravel locked in place, Wurster Engineering and Construction was able to install supplemental support jacks under the temporary retaining wall. After the jacks were in place, they were able to install the soil nails followed by the shotcrete.

Painless Procedure

Approximately 50 gallons of AP Fill 720 were used to build this solidified wall of gravel behind the remaining brick wall. Injection probes were spaced 18” apart to ensure proper permeation and coverage needed to create one solid mass. The crew came in at a steep 20 to 30-degree angle behind the brick and put in about 2 gallons of polyurethane per probe, with 5% catalyst mixed in. The crew then installed more probes at a shallow 60-degree angle in the areas that needed further permeation and coverage. These extra placements of approximately 2 gallons per probe were essential to keeping the gravel in place from side to side and front to back. This entire process took one day to complete with a small crew of three people.

Rapid Result

The day after grouting, the site work demolition subcontractor chiseled off the remaining brick from the solidified AP Fill 720 gravel wall - and the project was determined to be a complete success. The entire job was finished quickly with minimal mobilization costs. We appreciate our friends at Wurster Engineering and Construction for trusting Alchemy-Spetec’s material and consultation for geotechnical projects such as this one.

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One of the most common questions I get about leak seal grout is along the lines of "Can I do this or that? Will it work?". I get this type of question regularly because every job is very unique and there is no one precise grouting procedure that fits everything. Let me introduce you to a term I love to use: exploratory grouting. This is the phase in which you are trying various methods until you find one that works for your particular application. While this just sounds like guesswork, it is very far from that.

So, I have come up with a short three-item list of the things you should not do while chemical grouting with urethanes:

1. Do not eat the grout!
2. Do not get the grout in your eyes!
3. Do not add water to the grout before pumping it. (Actually, there are rare times you do this.)

If you do not break those three rules, your work falls under exploratory grouting. We have a standardized leak seal crack injection procedure that will maximize your result (in a laboratory setting). But concrete restoration does not happen in a laboratory. Start with the procedure, but understand that the procedure is written for the spirit of what we are trying to accomplish. It is not written in stone (as long as you're following the three rules I have listed above).

Pro tip: Number one, do not eat the grout, seems like a no-brainer but it exists because we had a call from someone saying, "My worker ate your grout". 

In summation, remedial waterproofing is often an explorative process and can require on-the-fly adjustments. Setting expectations, maintaining open communication with all involved parties, and attention to detail are essential to making the waterproofing process efficient and successful. Here at Alchemy-Spetec, we have a wealth of experience navigating all types of waterproofing projects. We look forward to assisting you with your specific needs.

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New year's message from Alchemy-Spetec Co-Owner and President Stephen C. Barton. (Stephen has been at the forefront of the concrete repair industry for over 30 years. Running leak seal crews in his teens, developing breakthrough polyurethane technology in his twenties, and helping grow the market ever since; Mr. Barton has been a leader in the field for most of his life.)

At the end of every year, I tell my team the same thing. “We have to reinvent ourselves. What got us to this point won’t get us where we want to go.” Every year we do just that. However, 2021 was special. We had to reinvent ourselves just about every month.

I won’t waste your time by repeating the phrase “supply chain issues”. I will say this: our team worked exhaustively to scour the earth for raw materials, reformulate our products, and finally manufacture and test the new formulations. In the end, we did everything in our power to live up to our entire reason for being – to serve our customers.

We learned more in the last year than we have since the inception of the business. We have more raw material options, formulations, and test data than ever before. These lessons learned will help us serve our customers more effectively than ever in 2022.

A lot of people are looking forward to putting 2021 in the rear-view mirror. Personally, I’m going to miss the challenges from last year that forced us to learn and grow. However, I’m sure 2022 will present some of the same issues and some unexpected new ones. I say, “Bring it on!” What doesn’t kill you makes you stronger.

Finally, I would like to say “Thank you” to all our customers who patiently waited for material to show up and endured the sticker shock of rapid inflation. Our team will be there for you again this year. Happy New Year! Now, let’s get to work…

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It has become an Alchemy-Spetec holiday tradition to re-post this safety blog I wrote a few years ago.  Merry Christmas and Happy New Year!  (Andy Powell - Alchemy-Spetec Southeast Regional Manager.)

This time of year, most people will spend a little extra time with their loved ones.  It is also a time to reflect on the loved ones we miss that are no longer with us.  Like most of us, I know people who have either been lost or have suffered through a loss.  In those cases, there was nothing that could have been done to stop it.  However, there are things that we can do to guard against job-related safety hazards.

I've been fortunate enough to spend time in an OSHA safety training class.  It was required in order to be present supervising a project at a chemical facility.  Signing in at 6 AM, I’ll admit I was not looking forward to spending all day there.  By the end of the day, I was glad that I went.

In an intro video, the narrator said that every morning when you kiss your loved one goodbye before you go to work, keep in mind that someone, somewhere will not come home from work that day.  Workplace accidents are almost entirely preventable.  Investigations typically find the cause quite easily. 

The class I attended contained a dozen or so modules, each one with a video case study followed by the teaching.  Every case study module covered a different accident where people didn’t come home from work that day.  All of them could have been prevented.  I learned about fire, electrical and chemical safety; as well as confined space, ladders, scaffolds, and working in trenches.  I have worked in the construction industry since my teenage years, so it was sobering to look back and think about some of the close calls I had.

If you're a contractor or industry-related business owner looking for a good investment, send your employees to one of these classes.  It’s an excellent opportunity for them to learn safety principles that can protect you, your other employees, and your business from being lost.  It’s a gift that will keep on giving.  You don’t need Christmas as a reason to do this, but in the spirit of the season, you may want to make it the reason.  

Click here to find an OSHA safety class near you.

Merry Christmas and Happy New Year!

Do you know that leak that returns every year no matter how much hydraulic cement you put on it? Why not make this next time the last time you have to mess with it? Polyurethane grouts have some unique properties that allow them to do things concrete cannot. One of the most glaring is its flexibility.

I like to ask the question, "What is the difference between a joint and a crack?" A joint was engineered by humans while mother nature adds her cracks where the engineer did not see the need for one. They allow the concrete the ability to flex a bit as needed. These cracks can be caused by temperature changes, loading, and unloading, or even a difference in the coefficient of expansion of dissimilar materials, like a metal pipe in a concrete wall.

So, as you pick up that bucket of hydraulic cement, ask yourself, "Is this a dynamic leak? Is movement the issue at hand?" More often than not, movement is the issue and the solution is a flexible polyurethane grout. Spetec PUR GT500 and Spetec PUR F400 are two of the main Alchemy-Spetec grouts used in parking garages, elevator pits, and such. Spetec PUR GT380 is the main grout when it comes to sewers, wet wells, and the like. All of these grouts are highly flexible, NSF 61 certified for contact with drinking water, and allow the concrete to move without allowing it to leak.

Another misconception is that a repair material needs to be dry to effectively waterproof a structure. With polyurethanes that is completely wrong. We want and require water present when injecting the urethane grouts.

So, in summary, the best practice is to quit using hydraulic cement in situations where it will fail because of movement. Instead, waterproof once and effectively with a flexible polyurethane grout and be done with it.

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Polyurethane foam was first discovered in 1937 by Dr. Otto Bayer who lived in Leverkusen, Germany. Bayer was a German chemist and was the head of the research group that discovered this new material. His fundamental idea of combining small volumes of chemical substances together to react into a dry foam material was viewed to be an impossibility. But after many trials and difficulties, Bayer eventually succeeded in synthesizing the first polyurethane foam.

Polyurethane was initially used as a cheap replacement for rubber. Widespread use began in World War II when many other materials became scarce. Polyurethane use quickly spread as a key component in many products, from specialized paper to protective military garments to gloss finishes and protective coatings.

In the 1950s, many companies such as DuPont, BASF, Dow, and Union Carbide started producing polyurethane for an even wider variety of applications including adhesives, insulation, and foam upholstery cushions. By the 1960s, polyurethane began being used for grouting purposes as we know it today. Here’s a brief snapshot of the history of polyurethane grouting:

• The 3M Company in the United States and Takanaka in Japan both introduced polyurethane grouts in the 1960s.
• 3M’s product was called Elastomeric Sewer Grouting Compound. As the name indicates, it was intended for use in underground utilities.
• Takanaka’s product was called Takanaka Aqua-Reactive Chemical Soil Stabilizer (TACSS). As the name indicates, it was intended for use in soil stabilization projects.
• In the early 1980s, DeNeef obtained the rights to TACSS and began distributing polyurethane grout worldwide. By the mid-1980s, there were almost a dozen manufacturers of polyurethane grouts.

Alchemy-Spetec CEO Stephen C. Barton started his career pumping 3M 5600 to seal cracks in the Atlanta subway system back in 1985. He was amazed at what it could do back then, and we're all still amazed at what our products do today. Despite still being specified in outdated documents, 3M exited the business many years ago and no longer manufactures the grout. In the last few decades, polyurethane grouting has become a widely accepted method for sealing leaks, stabilizing soil, and lifting slabs.

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The Alchemy-Spetec structural repair product line consists of products for patching, joint filling, spall repair, anchoring, and bonding.

Cementitious Patching Material

AP Gel Patch is a polymer modified, cementitious patching material for structural repair of deteriorated concrete. For use on above or below grade structures. It can be used on vertical or overhead structures. Read more...

Poyurea Joint Filler

AP Joint Fill 800 is a two-component hybrid polyurea joint filler with fast reaction allowing for shave time in as little as 5 minutes. The fast reaction allows for minimal down time and facilities to be in operation quickly.  Read more...

Polyurethane Spall Repair

AP Fast Repair 850 is a zero VOC, two-component polyurethane system. The high-quality thermoset is designed for fast repair of concrete (spalls, cracks, etc.). Its low viscosity allows for maximum penetration into cracks and porous concrete. This product can be mixed with up to equal parts oven dry silica sand to increase product yield and compressive strength.  Read more...

Non-Sag Epoxy for Structural Anchoring/Bonding

AP NS950 Epoxy is a two component, non-sag structural epoxy designed to offer exceptional mechanical strength in anchoring/bonding applications. Due to its high bond strength to concrete, it is ideal to use for anchoring threaded rod or rebar dowels. The consistency of AP NS950 EPOXY is good for capping for crack injection or general surface repairs. AP NS950 EPOXY is 100% solids, VOC free and Butyl Glycidyl Ether (BGE)* free.  Read more...

Low-Viscosity Expoxy for Structural Bonding of Cracks

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AS Pump Flush is a high-performance pump flush that is friendly to the environment and does an excellent job flushing out injection pumps. AS Pump Flush is a new and improved version of AP Flush 121 and Spetec Pump Cleaner.

Features

• New and improved formula.
• Now with more powerful iso neutralizers.
• For use with most Alchemy-Spetec pumping equipment.
• Available in 5 Gallon Pails.

Benefits

• Iso neutralizers protect your pump and hoses.
• Longer flush shelf life.
• More repeated flush use.

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When an old brick retaining wall in downtown Greenville collapsed and crushed three cars, Wurster Engineering and Construction was called in to stabilize the embankment and install a new wall system. Based out of Greenville, SC, Wurster is a geotechnical engineering and construction firm that specializes in soil and embankment stabilization. The project would require removal of the remaining brick wall, soil nailing the embankment, installing a shotcrete wall, and then tying in a new brick wall to the stabilized embankment.

However, one problem remained. There was one area where there was a portion of the brick wall that needed removal, but the temporary concrete retaining wall to protect the property had been poured on a bed of gravel that was being held in place by the remaining brick. The gravel under the temporary wall footing was contained by the remaining brick, which when removed would cause all of the gravel to run out. This section was about 30-35’ long, 2’ high, and 4-5’ deep from the face of the wall to the back.

Powerful Polymer

In order to solve this issue, Wurster Engineering and Construction selected AP Fill 720 to permeate the gravel and hold it in place while the brick was removed. This polyurethane resin was the ideal choice because of its ability to thoroughly permeate the gravel, lock it all together, and then cure to a high compressive strength. With the gravel locked in place, Wurster Engineering and Construction was able to install supplemental support jacks under the temporary retaining wall. After the jacks were in place, they were able to install the soil nails followed by the shotcrete.

Painless Procedure

Approximately 50 gallons of AP Fill 720 were used to build this solidified wall of gravel behind the remaining brick wall. Injection probes were spaced 18” apart to ensure proper permeation and coverage needed to create one solid mass. The crew came in at a steep 20 to 30-degree angle behind the brick and put in about 2 gallons of polyurethane per probe, with 5% catalyst mixed in. The crew then installed more probes at a shallow 60-degree angle in the areas that needed further permeation and coverage. These extra placements of approximately 2 gallons per probe were essential to keeping the gravel in place from side to side and front to back. This entire process took one day to complete with a small crew of three people.

Rapid Result

The day after grouting, the site work demolition subcontractor chiseled off the remaining brick from the solidified AP Fill 720 gravel wall - and the project was determined to be a complete success. The entire job was finished quickly with minimal mobilization costs. We appreciate our friends at Wurster Engineering and Construction for trusting Alchemy-Spetec’s material and consultation for geotechnical projects such as this one.

Want more information about soil stabilization?

As the weather gets colder, contractors in some regions will need to prepare their PolyBadger Lifting Systems for storage during the off-season. We're providing step-by-step instructions for that procedure in this article.

Prepping a PolyBadger for Winter Storage

1. Establish power to the cabinet and heat the hose (A heater, B heater, and hose) to the target temperature of 130° F.
2. Introduce material to the cabinet.
3. Turn the air supply on and recirculate to heat up the ISO and resin.
4. Once the PolyBadger is up to temperature, turn off the air supply and remove airlines from the stick pumps.
5. Remove the supply and the recirculation line from the A-side stick pump.
6. Drain all the remaining material from the pump and clean with brake cleaner.
7. Place the stick A side stubby stick pump into a 5-gallon pail of the AP Flush 121.
8. Reconnect the supply line and leave the recirculation line to drain in a purge pail.
9. Repeat steps 5-8 on the B-side stick pump.
10. Reconnect air supply to stick pumps, hold return lines in a purge pail, and slowly open the air valve on the stick pumps.
11. You will notice material slowly pushed out of the recirculation line into the purge pail. Continue to pump AP Flush 121 through the system until it comes out of the recirculation line clear, with no added color or debris.
12. Shut the air valve supplying the stick pumps. This will stop the flow of material.
13. Reconnect the recirculation lines to the appropriate stick pump and tighten.
14. Turn the recirculation pump valves to supply the hose.
15. You can remove the Handi Gun or leave it on for this stage, holding the hose in the purge pail. Turn on the supply valves on the end of the hose just before the Handi Gun. Slowly open the air valve on the stick pumps and pull the trigger on the gun.
16. You will notice material slowly pushed out of the hose line into the purge pail. Continue to pump AP Flush 121 through the system until it comes out of the hose line clear, with no added color or debris.
17. Shut the air valve supplying the stick pumps. This will stop the flow of material.
18. Remove the stick pumps from the AP Flush 121. (Make sure to mark your pails A and B for future use).
19. Insert stick pumps into AP Pump Saver 195. (Make sure to mark your pails A and B for future use)
20. Push the AP Pump Saver 195 through the hose line. You will notice the AP Flush 121 slowly pushed out of the hose line into the purge pail. Continue to pump AP Pump Saver 195 through the system until it comes out of the hose line clear (you will notice a thick, clean fluid).
21. Turn off supply valves on the hose just before the Handi Gun.
22. Disconnect the air supply to the stick pumps.
23. Move the hose supply valve into recirculation position to depressurize the system.
24. Shut off supply valves to the cabinet.
25. Turn off heat zones.
26. Turn off the main disconnect.
27. Remove residual grease from interior cabinet pumps.
28. Replace with new grease.

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