In a recent media interview, I was quoted as follows: “Ultimately, the customer is the property owner, somebody who’s got a problem. Even though we’re selling to contractors, we kind of all have to be on the same page.” That view has motivated us to pay close attention to what contractors, engineers AND property owners are most concerned about regarding the use of polyurethane. Over the years, we’ve noticed three main questions that arise over and over again:

1. Are the polymers strong enough?
2. Are they easy to install?
3. How quickly can the job be finished?

So we’re going to take a look at each of these three core issues in detail…

Powerful Polymers

Concrete Leveling Foams

In my blog post Slab Jacking With Polyurethane Foam – How Strong is Strong Enough?, I point out that the National Home Builders Association and the International Building Code list stiff clay as having a 4,000 lbs per square foot load bearing capacity and crystalline bedrock as having 12,000 lbs per square foot capacity. Our lifting foams have load bearing capacities of 7,200 to 14,000 lbs per square foot after curing in a free rise state. 

When Alchemy-Spetec foams cure in a confined state underground, that bearing capacity has been known to be even stronger. Testing data in the lab shows that our lifting foams will increase in compressive strength: In a space confined 25% by volume there will be an increase of 31% in psi and in a space confined by 75% there will be a 79% increase in the psi.

The Alchemy-Spetec lifting foams are used to level airport slabs supporting jumbo jets, heavy equipment, building slabs supporting tremendous loads, and even railway slabs supporting the heaviest freight trains.

Leak Seal Resins

Alchemy-Spetec leak seal resins have been used in many applications, including shutting down a 2-million gallon per day leak at a water treatment plant. The leak was reduced from 1,700 gallons per minute to just 10 gallons per minute (attributed to the many vintage valves and fittings that are still present at the plant). They are also used in other applications such as curtain wall grouting.

Soil Stabilization Resins

Unstable, eroded, or loose soil around infrastructure can result in settlement and damage to the structure. Voids can be filled, seawalls remediated, soil consolidated, and water migration halted by injecting the soil with Alchemy-Spetec soil stabilization resins. In my blog post Soil Stabilization Products Prevent Cave In Beneath Busy Intersection, I profiled a powerful example of AP Fill 700 in action. Inspectors in Orange County, Florida found a depression in the middle of a busy intersection that was due to an underground sewer line that wasn’t sealed. Water and eroding soil were infiltrating the sewer line causing the road to slowly settle. The resulting voids around the drainage structures had the potential to grow larger, eventually resulting in a complete cave-in of the roadway. A point repair was done from within the leaky pipe to stop the infiltration but they feared it was only a matter of time before the road gave way. We devised a solution for their crew to use the versatility of AP Fill 700 as both a permeation and void filling grout.  To keep the lane closure down to a bare minimum of time, the project was successfully completed on two separate Saturdays. The voids were filled, the loose soil was solidified, and only minor asphalt patching was required to make that area smooth for traffic again.

Orange County Utilities Supervisor Paul Morrison has been enthusiastic about AP 700 since the first time he tried it out on a severe manhole leak, when he had this to say…

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

AP Soil 600 is one of the most versatile permeation grouting products on the market. It can be characterized by its single component, moisture activated, hydrophobic, and low viscosity qualities. It can fortify sandy soil to strengths approaching 2,000 psi.

Painless Procedures

As I never fail to point out, application procedures for Alchemy-Spetec products are relatively painless. The installation process is very clean compared to replacing the structure or repairing with cement grout.  Polyurethane is lighter than cement, so it doesn’t sink. Alchemy-Spetec products do not shrink after installation. The closed cell structure makes these resins impermeable. 

Rapid Results

Application of polyurethane is usually less expensive than replacement. Polyurethane concrete repair is also less time consuming. Any structure repaired with Alchemy-Spetec products is usually ready for use 45 minutes after application.

There you have it – the three most critical issues for contractors, engineers and property owners regarding polyurethane concrete repair. By staying focused on these concerns we constantly remind ourselves WHY we do what we do. We do it for YOU.

Want in-depth info on polyurethane infrastructure repair resins?

As a technical consultant, I often assist customers when they're put to the test with difficult jobs. That's why we go out of our way to provide the powerful polymers and painless procedures they need to achieve the rapid results those projects require. For an in-depth dive into what we mean by powerful, painless and rapid - see this blog post I wrote awhile back. Then watch the video below to see powerful polymers, painless procedures, and rapid results in action... 

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Poor compaction, water erosion, broken pipes, and organic material in the soil can all lead to settling of a foundation or a roadway.  Traditional slab lifting can bring concrete and structures back into place but it doesn’t necessarily address the underlying issue or guarantee a long term fix.  Other methods of addressing deep soil issues require heavy equipment, extended down time, and collateral property damage.  These situations create problems for property owners as well as opportunities for the elite contractors that know how to fix them.

Alchemy-Spetec offers a unique combination of high quality structural lifting foams along with the equipment and training needed to address deep soil issues. Now you can achieve soil densification and lifting on large projects with the smallest footprint and least amount of heavy equipment required.

The Deep Lift™ process is powerful, painless, and rapid. Deep Lift™ gets to the root of the problems in the soil, it brings the structure back to level, and accomplishes this with minimal imposition or downtime to the property owner.

For a detailed explanation of the process, watch the animated video below... 

 Want more information on the Deep Lift process?

According to the Guinness Book of World Records, the honey badger is the world's most fearless animal. With ultra-thick skin and top of the line fighting instincts, this creature is not to be messed with. It boldly goes where similar animals consistently fear to tread. 

Let's take a deep dive into why Alchemy-Spetec's smallest slab lifting system, The PolyBadger, is named after this incredible animal. As Alchemy-Spetec regional manager Andy Powell mentions in this previous blog post...

"The Alchemy-Spetec PolyBadger lifting system is tough and compact. This system is an affordable entry-level slab lifting option for new contractors, as well as an extremely portable addition to the experienced contractor’s arsenal. The PolyBadger is a lot less expensive than your standard 20-foot trailer rig. The setup is simple and requires minimal equipment. The entire system can easily fit in the back of a pickup truck!"

Like the Honey Badger, the PolyBadger lifting system is both Tough and Compact

The PolyBadger slab lifting system is durably built and designed to go where other lifting systems simply cannot venture. Here's a quick rundown...

• The PolyBadger is smaller in size than most of the competition, at 30" wide and 48" long. Now that's what you call portable!
• This is one of the few systems powered through a common 120-volt wall outlet (vs the usual 240-volt requirement). Compatibility with common wall outlets exponentially increases your location possibilities.
• Essential elements (heaters, electronics, auto calibrator) are self-contained and protected in the cabinet for extra portability.  
• The cabinet is constructed from powder coated carbon steel and the frame is constructed from carbon steel box tubing. 
• The entire system is very maneuverable, resting on two swivel and two fixed 6-inch pneumatic castor wheels.  The wheels are are filled with light weight polyurethane instead of air, so they don't go flat. 
• The hose is built to last with a Teflon core and a stainless-steel braid. The system can operate with up to 200 feet of hose.

One last very important point:

Honey badgers are also mentally tough. They've been known to build stools with rocks in order to get over walls even break through locks on food freezers! Nothing stops them! The PolyBadger system's auto calibrator provides similar qualities to keep it going through thick and thin. As Andy Powell mentions in this previous blog post...

"The genius of the PolyBadger is the auto calibrator. It keeps the flow of A-side and B-side slab lifting material on ratio, eliminating the possibility of crossover clogging in the gun or the whip hose. The two low-pressure transfer pumps and auto calibrator are literally the only moving parts in the whole system. That means less downtime, less maintenance, and more productivity on the job."

Want more information on the Alchemy-Spetec PolyBadger lifting system?

Salt corrosion, tidal action, currents, boat wakes, storm surges and sometimes hurricanes all deliver a constant beating on the seawall. Contrary to popular opinion, many of the forces also come from the side of the wall facing the land. Did you realize that rainfall/storm events create more hydrostatic pressure than rising and falling tides? Every time it rains or the irrigation system runs, and every time the tide goes out; all of the groundwater above the waterline needs a place to vent or equalize. Massive pressure can build up if that water is trapped, making it impossible for it to drain into the sea or storm water system. That is a recipe for disaster which can easily be avoided with proper surveillance. Let's take a look at some of the external signs a seawall is in need of repair... 

Small Sinkholes Near the Wall

In landscaped areas, evidence of soil erosion is often quite obvious.  In this photo you can see that there is a small sinkhole developing at the inside corner of the seawall.  Some types of grass will actually keep larger sinkhole from being seen.  So check thoroughly.

Voids Near the Edge of the Wall

Obvious settling soil should have gotten the property owner’s attention in this case.  Too often, they ignore the warning signs until something more catastrophic occurs.

Cracking Concrete

Here, ground penetrating radar revealed loose soil zones beneath this concrete apron outside of a fish processing facility.  The steel sheet pile walls were losing soil and huge voids had developed.  Evidence of cracking concrete was not enough to get their attention as is often the case.  However, when a Lull forklift went through the slab, everything but foot traffic was prohibited from being on the apron.

Damage to Structures Up to 100 Feet Away

Capillary pathways of leakage can be found over 100 feet away from the visible leak, depending on the soil matrix.  The back of this pool deck had dropped about 6” already as the yard slumped towards the leaking seawall.

Causes of Seawall Damage – An Overview

Correct construction of a seawall will include a drainage system to handle the bulk of the water that comes from rain in addition to check valves, weep holes, or seams to handle the daily influx and outflow from tide and wave action. Although these systems are designed to retain the soil behind the seawall, over time the materials degrade or can be disturbed by settling.

This is a direct symptom of normal wear and tear from the natural environment and is unavoidable. The result is a loss of soil and the inevitable sinkholes and / or low spots that will occur along the wall. Other times, the weep holes and vents become clogged and the water has no way to escape except to force its way down and out from underneath the base of the wall. When this occurs there will again be sinkholes and sometimes wall failure.

Conclusion

When signs of sinking ground are observed, you can almost be sure there are voids below that are that are not seen from the above the surface easily and are indeed dangerous. Sometimes these voids can extend below an adjacent patio, dock, or pool deck, causing those to sink and crack as well. The key to keeping those problems at bay is to actively anticipate them.

If you live along the water, it is always going to be man against nature. That seawall is keeping your property from damage and from disappearing altogether. The key to extending the life of your seawall is the advanced polyurethane technology from Alchemy-Spetec. For more on the repair process itself, read An In-Depth Look at Polyurethane Seawall Repair. It's fast; clean, easy to install, and most of all, effective.

Want more in-depth info on polyurethane seawall repair?

In the previous post, An In-Depth Look at Polyurethane Seawall Repair – Part 1, we looked at causes of seawall deterioration, typical evidence of deterioration to look out for near seawalls, and the three most common seawall repair options: excavation, cement grout repair and polyurethane repair.

Now we’re going to take a deep dive into the qualities, applications and advantages AP Fill 700 – the Alchemy-Spetec product most typically used for seawall repair. We’ll also share a case study on a seawall crisis at an upscale marina that was resolved by contractors using AP Fill 700.

AP Fill 700 Advantages

AP Fill 700 is a single component, water activated, hydrophobic, low viscosity, closed cell polyurethane injection resin. In addition to seawalls, it’s a proven polyurethane concrete crack sealant for all types of structures. From our experience advising contractors, we’ve found it to be the most cost effective method for repairing seawalls.

Here are some of the advantages it has over other polyurethanes:

Lowest viscosity on market

AP Fill 700 has a viscosity of 110 to 130 cps. This allows for getting into thin cracks.

Closed cell, 0% permeability

The closed cell structure of this foam allows for ZERO percent permeability. No compromising of the repair material to worry about.

Adjustable set time

Adding various amounts of catalyst to adjust the set time allows for custom application of the material to address the specific nature of the seawall problem. A longer set time allows for the material to permeate and soak in around the structure before setting up. A shorter set time makes the material set up more immediately, which may be appropriate when there are large voids to fill or gushing leaks to stop.

Single component

This particular product does not require a “B” side to react with before setting up. This allows for simple, efficient installation.

Phthalate free

Some companies use phthalates in their polyurethanes. Because of their environmentally unfriendly nature, it’s not even legal to manufacture phthalates in the United States. Companies using them have to import them from overseas. Needless to say, AP Fill 700 does NOT contain phthalates – a known marine pollutant.

Approved for contact w/ drinking water

As mentioned in the previous post in this series, AP Fill 700 has been NSF certified for contact with drinking water. So, obviously installation in recreational or commercial bodies of water is no problem from an environmental perspective. Read more about NSF certification in the blog post Alchemy-Spetec's NSF Certification Spells Environmental Protection.

High bonding characteristics

Once AP 700 is installed, it’s NOT coming off. The adhesive qualities are unparalleled. This contributes to the vast advantage polyurethane has over cement grout when it comes to durability.

More about AP Fill 700

This material is designed to be efficiently delivered into all sized gaps and eroded depressions. It reacts with water or moisture in the soil and expands to fill the voids. It’s compatible with any seawall material: concrete, steel, vinyl, etc. And it permeates the most sandy of soils to form a solid, strong, watertight mass. It sets in less than 10 minutes. By being impermeable to water once in place, the likelihood of future erosion is vastly diminished. 

AP Fill 700 Applications

In addition to seawall repair, there are many other general applications for AP Fill 700. Here a few to keep in mind…

• Cutting off low and high flow leaks
• Concrete void / crack filling for all structures
• Cutting off underground water flows
• Soil stabilization
• Filling voids under concrete slabs
• Encapsulating contaminated soils

Durability

Leading experts in the polyurethane industry predict that this material lasts for hundreds of years once installed. Polyurethane is made from similar materials as plastic. There’s a reason why people campaign against the dumping of plastic waste in the middle of the ocean: it will be there forever. The edge of the ocean, properly installed as part of a seawall repair, is a much better place for it. And, yes, it tends to last forever.

Powerful

If needed, AP Fill 700 can quickly shut down leaks of thousands of gallons per minute. Rapid expansion makes it great for filling voids, wide cracks, pipe joints, pipe penetrations. Originally developed over 30 years ago, and continuously improved since, this technology has one of the longest histories of success in the field among uses of polyurethane foams

Efficient Installation

Results are immediately clear due to the visible exiting of sea water when the foam is injected. The low viscosity allows it to be injected into hairline, expansion joints and smaller cracks as well. AP Fill 700 is field proven in “curtain grouting” (earthen dam seepage protection), and consolidating loose soils.

Case Study

Let’s close out this two part series with a look at polyurethane seawall repair in action…

Situation

Owners of an upscale marina in Riviera Beach Florida noticed cracking in the slabs outside of their main boathouse. They also noticed that the slab had settled in several areas. The slabs in question were subject to heavy dynamic loads as a large forklift traversed the area, bringing 40' motor yachts in and out of the boathouse. Contractors came in and did a site evaluation, drilling holes to probe beneath the slab and also a sub surface investigation of the seawall to see if soils were being lost.

Solution

Most of the joints in the seawall were leaking sandy soil out - resulting in a void beneath the concrete slabs, which then cracked and settled. AP Fill 700 was specified to seal the concrete panel joints. It was injected behind the panels in the area of the joints, both vertically through the concrete, and horizontally from the water side of the panels. Proper venting was then installed to relieve hydrostatic pressure.

Results

The sandy soils have been stopped from escaping from behind the seawall. The concrete slabs were then lifted back into place with a combination of helical piles and AP Lift 475. There are no longer any voids beneath the slab so it is not flexing and cracking any longer. This marina was saved from a much larger, more catastrophic failure.

Want more info on polyurethane seawall repair?

The Spetec PUR H100 Hotshot Cartridge contains Spetec PUR H100, a one component, closed cell, hydrophobic, water reactive, solvent/phthalate free, low viscosity polyurethane injection resin for stabilization and water cut-off of large water leaks. The cartridge packaging is ideal for small jobs in locations that prohibit the use of pumps.

Advantages:

• Single component cartridge.
• Good compression strengths.
• Rapid set time.
• No volatile solvents.
• Cures to rigid foam.

Applications:

• Water cut-off.
• Dams.
• Manholes.
• Storm pipe joints.
• Box culverts.
• Limited access areas.

For details on preparation, application instructions, required tools and more, please download this Spetec PUR H100 Hotshot Cartridge datasheet.

Want more information on Alchemy-Spetec leak seal products?

Chemical grouts are commonly injected into leaking cracks and joints to stop the flow of water, sealing off cracks and filling voids. This procedure can be performed in both wet and dry situations, in potable water or wastewater tanks, and in a variety of other structures where water is leaking.

Procedure

Identifying and Preparing the Structure

• Clean crack surface using a wire brush, a grinder with wire cup wheel or other mechanical means, to remove mineral deposits, coatings or other debris. Pressure washing of the surface is also an option. If sever contamination exists, a chemical cleaner may be used, but must be flushed or neutralized before proceeding to the next step.
• When addressing wide cracks, use Oakum, hydraulic cements or epoxy gels as a surface seal over the crack prior to injection to contain chemical grout in the structure. When addressing high flow leaks, use Oakum soaked in chemical grout. Soak oakum in chemical grout and insert into the leaking crack or joint with a screw driver or similar tool. This will slow the water flow.
• pH notice: water used to activate Alchemy-Spetec chemical grouts must be in the pH range of 3-10 to achieve optimum performance.

Injection Port Spacing and Drilled Holes

• Port spacing is determined by the width of the crack: 3-4 inches apart in tight cracks and up to 24 Inches apart in wide cracks. Staggering ports from side to side (stitching) is always recommended.
• To intersect a crack at the mid-point, drill injection port holes toward the crack at a 45-degree angle, at a distance of one-half the thickness of the concrete. Example: In 12-inch-thick concrete, drill the injection port hole 6 inches back from the crack at a 45-degree angle to ensure crack is intersected at mid-point (longer drill bits may be needed to reach mid-point). See Diagram.
• Drilled holes should intersect the crack or joint at the midpoint, so the chemical grout can enter the crack in the center of the concrete and expand in both directions sealing the entire crack, filling any voids and micro cracks in the structure as the material expands and cures.
• Drilling injection holes is commonly performed using 3/8, ½, or 5/8-inch diameter drill bits.
• Flush drilled holes with clean water to remove dust and debris before inserting drive in port or mechanical packer.

Installing Injection Ports / Packers

• Various types of drive in ports and mechanical packers are available in the market.
• Drive in ports should be driven/hammered into the drilled hole until snug.
• Once the port is snug in the hole, insert a grease or zerk fitting into the port. Insert mechanical packers into the drilled holes until the top of rubber sleeve is just below the concrete surface.
• Tighten the packer using a wrench or ratchet, turning clockwise until firm. Do not over tighten.
• Install each port before injection but leave the grease coupler/zerk fitting off so you can monitor the travel.
• Avoid hammering on the grease coupler/zerk fitting.

Equipment and Equipment Set Up

• When using chemical grouts that are water reactive, use two separate pumps: one for water and the other for chemical grout. Caution: Never allow water to enter the chemical grout pump.
• Flush out the chemical grout pump and lines prior to use with an approved pump cleaning agent. This will ensure that the pump has no moisture in the system. Repeat flushing procedures when injection operations stop for a prolonged period of time.
• Pump hoses should be equipped with a high-pressure ball valve assembly. This allows easy connection to the injection port and an on-off grouting operation.
• Keep injection pump pressures low at the beginning of injection and increased slowly as needed to achieve full grout penetration. Extra high pump pressure may result in cracking or spalling of the concrete.

Flushing the Crack Prior to Injecting

• Flush the crack prior to injecting chemical grout to ensure that the crack is free of debris, that injection ports have intersected the crack, and that there’s enough water to cause the resin to react.
• Begin injecting water at the lowest port on vertical cracks or at one end (and then work across) on horizontal cracks. Continue injecting water until the crack has been flushed and clean water appears.

Injection of Chemical Grout

• Inject the liquid (catalyzed) resin into the injection packer.
• When injecting a vertical crack, start at the bottom and work upward as the material seals the crack.
• When injecting a horizontal crack, start at one end and work across the crack.
• REMEMBER: Keep pump pressures low at the beginning of the injection process and increase slowly as needed to achieve full grout penetration. Extra high pump pressures may result in cracking or spalling of the concrete.
• Inject at a rate that allows material to travel and completely seal the crack. Once you see material seep out at the adjacent port, pause injection and insert a grease coupler/zerk into that port. Then resume injection on the existing port.
• Advance to the next port when movement of material has stopped on the existing port, or when material is exiting the crack at an excessive rate.

Completion and Clean-up

• After fully injecting the crack with chemical grout, attempt to re-inject water into each port to ensure that the crack and drilled holes have been completely sealed.
• Next, remove each injection port/packer by pulling the port/packer out of the structure, or by drilling them clear to below the surface by 3 inches or more.
• After removing the ports/packers, fill the injection holes with hydraulic cement, non-shrink grout or epoxy gel material.
• Remove any wasted cured resin, used ports/packers, and construction debris.

COMMON MISTAKES TO AVOID

• Drilling too close to the crack can cause spalling of concrete.
• Drilling too close to the crack will not allow material to seal entire crack, which can result in re-occurring leaks.
• Injection of cracks with manual equipment (ex. grease guns) will not produce enough volume and may cause extreme waste and injection failure.
• Poor preparation of wider cracks may cause material waste, lea–ding to re-occurring leaks.
• Injection pump pressure which is too high can cause spalling and damage to the surface.

Chemical grouting for leak-seal applications can provide contractors a specialty repair service that will always have relevance and demand in below-grade structures and water-holding structures. By following these steps for product, packer, and pump selection, you will be on the right path to a successful leak-seal repair. For more details and information on the leak-seal methodology, please contact a knowledgeable Alchemy-Spetec team member.

Want more information on building a leak seal methodology?

Once the material is selected, an appropriate piece of equipment must be selected for dispensing the material. For most polyurethane injection resins, single component high-pressure piston pumps are required. These are typically electric airless design, but can also be pneumatic, drill-operated, or hand powered. Alchemy-Spetec offers the full line of Titan pumps with various ranges of pressure and volume. The Titan 440 is a good pump for small injections, or to act as a water flush pump to clean drill holes and to ensure drill hole intersects the crack or joint. For higher outputs, it is recommended to use the Titan 640 or PowrTwin 8900. These pumps will be much better equipped for large volume applications such as curtain grouting, or for single component soil injection applications. For small cracks and joints, Alchemy-Spetec offers the Drill Pump. The Drill Pump is drill-operated and capable of handling pressures as high as 5000psi. It is easily maintained and produces very minimal waste due to the small hopper size and mixed batches. For acrylic injections, a stainless-steel pump, the Alchemy-Spetec Gel Pump is required. Due to the oxidizing nature of the B-side sodium persulfate, stainless equipment is required. 

The coupler at the end of the hose set will be dependent upon the type of zerk fitting discussed in part 2 of this blog series. A button-top valve requires a sliding coupler, the Alchemy-Spetec ACP-2204, or the standard zerk coupler, ACP-2201. It is always recommended to have several couplers on-site as the injection grouts will eventually cure in the couplers and prohibit the passage of material. It is also recommended to keep a spare piston kit or packing kit for any pump and to have received training on the appropriate replacement technique should it need to be changed. 

Chemical grouting for leak seal applications can provide contractors a specialty repair service that will always have relevance and demand in below-grade structures and water-holding structures. By following these steps for product, packer, and pump selection, you will be on the right path to a successful leak seal repair. 

Want more information on building a leak seal methodology?