Alchatek Blog

Management at a luxury hotel in Atlanta contacted geotech specialists Panhandle Seawall and Infrastructure after discovering significant voids beneath their swimming pool during routine maintenance. What began as a standard pool inspection quickly escalated into a serious structural emergency that threatened the integrity of part of the building. PSI was able to mobilize within days, providing temporary support until the foundation contractor could underpin the column footing and provide a permanent solution.

Initial Assessment

The investigation began when hotel maintenance staff noticed several concerning issues:

• Visible cracks developing in the pool structure.
• Accelerated water loss beyond normal evaporation.
• Significant increase in monthly water bills.
• Further investigation revealed an approximately 800 cubic foot void beneath the pool.
• A critical structural issue where a column footing was precariously supported only by the edge of a rock formation.

The severity of the situation led to a partial condemnation of the hotel structure, requiring immediate intervention to prevent potential catastrophic failure.

Proposed Solution

After careful evaluation by the project engineers, AP Lift 475 was selected as the optimal solution due to its superior characteristics:

• Higher density formulation for enhanced structural support.
• Superior bearing capacity to meet engineering requirements.
• Rapid deployment capabilities for emergency situations.

The project required approximately 300 gallons of material, deployed in three separate sets, to provide the necessary structural reinforcement.

Procedures

1. Safety Implementation

• Installation of proper ventilation systems.
• Deployment of temporary support beams.
• Setup of adequate lighting for the work area.

2. Grout Implementation

• Initial deployment of the Deep Lock® method to solidify underlying soil.
• Systematic void filling through carefully timed injection intervals.
• Continuous monitoring of material flow and structural response.
• Progressive filling to ensure complete void elimination and stabilization of footing.

Results and Conclusion

• The emergency shoring proved successful on multiple fronts:
• Complete stabilization of the compromised column footing.
• Establishment of solid connectivity between the underlying soil and structural elements.
• Prevention of further structural degradation.
• Removal of condemnation threat to the building.
• Restoration of structural integrity to engineering standards.

The project demonstrated the effectiveness of polyurethane void fill as a rapid response solution for critical structural emergencies, successfully averting potential building failure while providing a long-term stabilization solution.

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The owner of a gas manufacturing facility contacted a Georgia-based contractor regarding significant floor settlement issues, with a warehouse slab dropping approximately 3-4 inches. The settlement made issues for the forklift traversing in and out of the warehouse and posed a risk to the workers.

Initial Assessment

Upon arrival at the site, the team conducted a thorough investigation. Using a probe, voids were identified beneath the slab, with the probe sinking up to 2 feet in some areas. A Dynamic Cone Penetrometer test revealed large voids 2-4 feet below the slab.  Poor drainage was evident, with improper crowning causing water to flow towards the building instead of away from it. Interestingly, a layer of unusually hard clay was noticed outside the building, suggesting possible prior remediation attempts.

Proposed Solution

AP Lift 430 was chosen for this project, providing an excellent injectable polyurethane grout solution. With its impressive 22x expansion capability and 7,200 psf compressive strength, it’s ideal for warehouse slabs that support heavy equipment. The grout’s hydrophobic properties ensure long-term stability by blocking water infiltration that could otherwise lead to void formation.

Procedures

1. Deep Injection (Void Fill)

• 32 injection points were established in a grid pattern (16 on each side) at 4 ft apart.
• At each point, the team injected 15-20 pounds of material at about 5 feet depth.
• A slight lift (approximately 1/16 inch) during this phase indicated successful void filling.

2. Slab Lifting

• Additional holes were drilled next to the wall, 3 feet from the wall, and 9 feet from the wall (6 feet from the first row).
• Injection began from the holes nearest to the wall and moved outward.
• Multiple passes were made, with some areas requiring 3-4 injections.
• Gradual lifting was employed to prevent slab cracking.
• Dial indicators were used to ensure even lifting across the warehouse floor.

Results

The project successfully stabilized the warehouse floor and restored it to its proper level. Effective void-filling addressed the underlying instability, providing a solid foundation for the slab. Success was evident in the restored functionality of the warehouse space and the elimination of safety hazards posed by the uneven floor. The property manager was pleased with the work and requested additional slab lifting services for their other facilities.

Want more information on lifting slabs with polyurethane?

Essential Details

Dates/Pricing (Discount Deadline Extended!)

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of the day, March 2nd. $745 March 3rd and later. ($50 discount for each additional participant.)

Location

Atlanta, GA

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

Essential Details

Dates/Pricing

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of the day, February 25th. $745 February 26th and later. ($50 discount for each additional participant.)

Location

Atlanta, GA

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

A concrete staircase in a prominent mixed-use complex in Atlanta needed urgent repairs due to a set of 75-foot-long sunken steps. This issue posed a significant trip hazard, potentially compromising visitor safety. The problem stemmed from a combination of factors working together over time. Water infiltration through expansion cracks had created voids beneath the stairs, weakening their foundation. Compounding this issue was the natural tendency of separate concrete pieces to expand and contract, moving independently. This movement was particularly problematic as it caused the steps to separate from the adjacent sidewalk. Over time, the repeated cycles of expansion and contraction, coupled with the underlying voids, led to the steps sinking and rolling, creating a hazardous situation. 

Local experts from Engineered Restorations were called in to tackle this tricky situation. The team faced the challenge of addressing safety concerns while preserving the structural integrity of the staircase.

Powerful Polymers

AP Lift 430 was selected as the repair material for this restoration project. This polyurethane foam has expansive properties that are suitable for lifting sunken structures. Once cured, AP Lift 430 provides support for long-term stability, aligning with the project's requirements.

Painless Procedures

The repair process began with an assessment of the trip hazard. This allowed the team to determine the extent of the problem and plan their approach. Next, backer rods between the steps and sidewalk were removed to prepare the area for treatment. Alchatek Surface Guard 125 was applied around the injection area to prevent any excess polyurethane from bonding to the concrete. Protective sheets were placed to shield nearby glass surfaces.

The team drilled holes through the 8-inch concrete steps to reach the underlying soil. Soil probes revealed firm underlying conditions. The team then implemented their injection strategy. They created an initial foam layer slowly, injecting it just once every ten seconds. This gradual approach prevented existing hairline cracks from expanding during the lifting process. The team continued to inject AP Fill 430 until the steps were level. Finally, they redrilled and applied a second injection layer beneath the first to fill any voids created in the process. New backer rods were then installed.

To enhance the longevity of the repair, the team took an additional crucial step. They sealed the expansion joints with silicone, creating an optimal water barrier. This silicone sealant is flexible, accommodating future expansion and contraction. This extra measure was designed to protect the structure from water infiltration and movement, addressing the root causes of the original problem. 

Rapid Results

In just four hours, the steps were restored to a level position, aligning with the adjacent walkway. This efficient repair method addressed the immediate safety issue while extending the structure's lifespan. By lifting the existing steps rather than replacing them, the property owner avoided substantial expenses associated with demolition, new materials, and extended labor time for a complete replacement. This approach ultimately provided significant cost savings.

Want more information on concrete leveling with polyurethane?

Essential Details

Dates/Pricing

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of day, February 25th. $745 February 26th and later. ($50 discount for each additional participant.)

Location

To Be Determined
(in Georgia)

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

At a new solar field installation in North Florida, there were areas of bad soil where the H piles were not passing the loading and pull testing.  Solar panels lay at an angle, and if a strong wind is coming from one direction, it can try to “lift” the panel and pile.  Conversely, a strong wind coming from the opposite direction creates a downward force and can drive the supporting pile into the soil.

Powerful Polymers

The general contractor contacted the grouting specialists at Stable Soils and asked if they could use cement grout to try and lock the piles into place. Because of the tight confines between rows of piles, the specialist suggested a polyurethane permeation grout, Alchatek's AP Soil 600. The required installation equipment is more compact and it is a lot cleaner to install than cement. AP Soil 600 is moisture-activated (the same as Gorilla Glue), but it only takes about 5% moisture in the soil to make it react.  AP Soil 600 is heavier than water by design, and it is also hydrophobic.  As it soaks in, it pushes through the moisture and displaces it.  Once it cures, the sand is locked together. As the AP Soil 600 soaks into the damp sand, it reacts and produces carbon dioxide.  The CO² creates a swelling effect, driving the resin further into the sandy soil.

Painless Procedures

Around 20 test piles were installed at the solar field.  AP Soil 600 was injected right against the steel at a depth between 3 and 4 feet.  About 1/3 of the piles received 1-1/2 gallons.  Another third received 1 gallon, and the final third was injected with 3/4 of a gallon.  All of the piles passed the pull testing and compression testing.  The project was awarded, and around 4000 piles were injected in total.  It was a complete success.

Fast forward to 2022 at a massive solar field installation in Ft. Green, Florida.  Like many solar fields, it was not necessarily on the best land.  The site was a filled-in phosphate mine, so the soil was layered with bands of clay, sand, and mine tailings. Once again, there were sections of the solar field where the piles were not passing the pull testing, load testing, and lateral testing.

Polyurethane grouting was proposed but the manufacturer of the components wanted the proposed material to go through more vetting.  Primarily they wanted to know if the polyurethane grout would last for the 25-year service lifespan of the solar field.  Job histories, accelerated testing results, and chemical resistance data was provided, to their satisfaction.

For this project, the owners wanted to get engineers involved in the grouting portion of the installation.  Mathers Engineering was in charge, and they contracted Madrid Engineering to handle the soil testing. Testing showed that there were layers of clay and sand (referred to as zebra striping), so the grout was targeted in the sandy areas.  The thought was that the permeated sand would be locked in between layers of clay, thus improving both compression and pull strength. 

For this installation, the same three different volumes of AP Soil 600 were tested.  Once again, only 3/4 of a gallon was deemed sufficient to pass the testing, so that was what was used.  5000 piles were injected on this project, about 90% of them with AP Soil 600.  There were some areas of organic soils, and for those, AP Fill 700 was injected and tested successfully.  AP Fill 700 has over 30X expansion and works well at improving organic soils.  The work was completed in the Spring of 2022, and the solar field went into service.

Rapid Results

In the Fall of 2022, disaster struck Ft. Green, a location unfortunately positioned directly in the path of a Category 3 hurricane. The storm’s ferocity was evident as it swept through, leaving behind a trail of destruction in its wake. Trees were toppled, and the solar field, designed to endure winds exceeding 100 MPH, faced unprecedented damage. The wind from the hurricane’s eyewall proved too powerful, driving piles of solar panels into the ground. Despite their robust design, many panels were shredded, and a significant number of the piles suffered movement, highlighting the sheer force of nature’s fury.

Out of 5000 piles injected, only 9 showed any sign of movement.  The polyurethane grout was put to the test and passed with flying colors.  Currently, this field is going through the insurance claim process, but the testing for the repair method has already been completed.  The embedded piles were jacked back up to level and then grouted in place with AP Soil 600.  All of them passed the test; now, the field is waiting for the insurance to be worked out so the rest of the damaged piles can be glued back into place. AP Soil 600 carries the NSF / ANSI 61 rating.  It is safe for contact with potable water, and in this application, it will not leach any chemicals into the soil or groundwater.

Want more information on stabilizing soil with polyurethane?

The owners of a college apartment complex in Georgia reached out to a local engineering firm after discovering a large void underneath the northwest end of the building. The issue was caused by stormwater collecting and flowing beneath the building's foundation. Over time, the foundation became exposed and now the grade has lowered by a foot from the original design.

Site Investigation and Initial Attempts

A dynamic cone penetrometer test revealed the soil was fragile, with two to three blow counts for the tested areas. Underpinning piles had been installed by the previous owner, but did not did not adequately stabilize the building's foundation. The shifting foundations caused the ceiling and wall in one of the top-level rooms to begin to crack and showed early signs of separation.

Proposed Solution

The engineering team recommended using injectable polyurethane grout. AP Lift 430 was selected for the job because of its high expansion of 22x and compressive strength of 7,200 psf. This polymer is also hydrophobic, which prevents water from causing further erosion of the void.

Implementation

1. Rod Placement: Injection rods were inserted horizontally into the void’s back, spaced 4 feet apart.
2. Foam Injection: Foam was injected through the rods until emerging from the exposed void area. This step ensured that the foam reached the farthest areas of the cavity.
3. Free-Shooting: The remaining exposed void was filled by direct foam application, ensuring comprehensive coverage.

Results and Conclusion

The end result was 658 gallons of expanded AP Lift 430 injected underneath the void. The polyurethane injection, combined with regrading work done in collaboration with a local engineering firm, successfully solved the issue and prevented further void formation underneath the student housing.

Want more information on geotechnical polymers and equipment?

Foundation foam is a trusted solution for engineers and contractors addressing soil stabilization and structural support challenges. This proven technology effectively tackles issues caused by unstable soil, from erosion to poor compaction. Over the years, it has established itself as an essential tool for maintaining the integrity of buildings, roads, and other infrastructure.

Why Soil Stability Matters

Unstable soil poses significant risks to structures built upon it. For instance, erosion, poor compaction, and freeze-thaw cycles can lead to settling, cracking, and even catastrophic failure. Moreover, these issues often occur deep beneath the surface, making them difficult to address using traditional methods. Therefore, reliable solutions are crucial for ensuring long-term structural integrity.

The Power of Foundation Foam

Foundation foam offers a dependable solution to these challenges. Unlike conventional methods, it can be injected deep into the soil without heavy excavation equipment, allowing for precise soil stabilization and compaction. Furthermore, the foam cures quickly. This rapid curing time significantly reduces project downtime and improves overall efficiency.

One-Component Standard Soil Stabilization

One-component foundation foam products offer durable and effective solutions for standard soil stabilization projects. These products are perfect for soil permeation, spreading through, and strengthening loose or unstable soil.

• AP Soil 600
• AP Fill 700
• AP Fill 720

Their ability to permeate soil makes them excellent choices for addressing issues like erosion, poor compaction, and water infiltration. As a result, these one-component foundation foam solutions can effectively stabilize soil without requiring extensive excavation or heavy machinery.

Two-Component Deep Lock® Stabilization

The Deep Lock® process utilizes two-component foundation foam products for deep soil issues. These include:

• AP Deep Lift 420
• AP Lift 430
• AP Lift 440
• AP Lift 475

The Deep Lock® process allows for soil stabilization at greater depths, thus making it particularly useful for large-scale projects or structures with significant foundation issues. Additionally, this method can achieve soil stabilization and compaction with minimal surface disruption.

Versatility in Application

One of the critical advantages of foundation foam is its versatility. It can be used in a variety of scenarios, including:

• Supporting settled buildings
• Enhancing soil density around pipes and tunnels
• Reinforcing bridge approach slabs
• Strengthening port and airport infrastructure

Foundation foam provides long-lasting support and protection against future settling or erosion in each application. Consequently, it has become a go-to solution for many construction and rehabilitation projects.

Comparing Foundation Foam to Traditional Methods

Compared to traditional soil stabilization methods, foundation foam stands out in several ways. For example, cement pressure grouting requires heavy equipment and can be messy and imprecise. Similarly, helical piers and push piers, while effective, are often more invasive and limited in their application.

In contrast, foundation foam is less invasive, faster to install, and addresses underlying soil issues more comprehensively. Moreover, it can be combined with other methods for even more effective results. Therefore, it offers a more flexible and efficient solution for many soil stabilization projects.

Environmental Considerations

An important aspect of foundation foam is its environmental safety. Alchatek foundation foams are NSF-certified to strict ecological standards. This certification ensures that the cured foam won't negatively impact groundwater quality. As a result, these foundation foams are a responsible choice for projects in environmentally sensitive areas. This rigorous environmental compliance further enhances their appeal as a trusted soil stabilization solution.

Long-Term Benefits

The long-term benefits of foundation foam are substantial. Once cured, the foam creates a stable, water-resistant barrier lasting decades. This longevity translates to reduced maintenance costs and improved structural integrity over time. As a result, property owners can enjoy peace of mind knowing their investments are protected for years to come.

A Solid Foundation for the Future

Consistently providing an effective solution to soil issues, foundation foam has proven instrumental in ensuring the longevity and safety of buildings and infrastructure worldwide. With its track record of success, foundation foam continues to be a go-to choice for construction and rehabilitation projects of all sizes. This time-tested technology remains at the forefront of creating stable and resilient structures for the present and future.

Want more information on stabilizing soil with foundation foam?

Are you a geotechnical contractor facing challenges with unreliable lifting foam that leads to costly callbacks? You can significantly reduce these issues by choosing quality lifting foam from a manufacturer focused on slab lifting applications. The right solution makes all the difference in achieving consistent, successful results.

The Painful Costs of Job Callbacks

The financial impact can be severe when callbacks occur due to subpar lifting foam. You can lose revenue when you have to redo jobs without additional payment. Meanwhile, new project starts may be delayed, creating a ripple effect throughout the schedule. As a result, resource allocation becomes inefficient, further straining the business.

Impact on Business Reputation

Low-quality foam products can severely damage customer relationships. Negative online reviews may start appearing, which can hurt your lead-generation efforts. Property managers and other repeat customers may look elsewhere for future projects. Moreover, the likelihood of receiving valuable referrals decreases substantially. In this competitive industry, maintaining a solid reputation is essential for long-term success.

Benefits of a Specialized Manufacturer

Choosing a manufacturer focusing exclusively on polyurethane for slab lifting makes a notable difference. Specialized manufacturers maintain rigorous quality control standards throughout the production process. Furthermore, this dedicated approach ensures that you receive consistent results with every application. This approach provides better outcomes than relying on a general foam manufacturer who could be producing everything from spray foam insulation to material for couch cushions.

Quality Lifting Foam: The Foundation of Success

Reliable quality lifting foam leads to satisfied customers and more substantial business growth. With proper materials and consistent results, contractors can build lasting relationships with repeat customers while maintaining a solid reputation in the industry. 

Want more information on quality lifting foam?