Alchatek Blog

One Atlanta Plaza experienced significant settling of sidewalks and approach slabs around the perimeter of the building, creating safety hazards for pedestrians and visitors. The multi-story structure includes underground parking levels supported by piles, which remained stable, but the transition areas connecting to surrounding sidewalks were built on compacted fill. Over time, differential settlement occurred between the pile-supported structure and the soil-supported approach slabs, with some areas dropping approximately half an inch. Building management had previously attempted fixes by creating concrete "ramps" at transition points, but these temporary solutions continued to deteriorate as settlement progressed.

Initial Assessment

Engineers inspected the site and identified that the compaction difference between the soil immediately adjacent to the building foundation and the surrounding area was causing uneven settlement. This resulted in cracking of curbs, trip hazards at entrance points, and visibly sagging pavement sections, particularly noticeable at the approach to the parking garage. The most affected areas showed clear separation between the stable pile-supported structures and the settling exterior slabs. Entrance points where the differential settlement created ADA (Americans with Disabilities Act) compliance issues, and potential liability for trip-and-fall incidents were of particular concern. This problem stemmed primarily from inadequate soil compaction during the original construction.

Proposed Solution

Alchatek recommended a two-phase approach to address both the underlying soil conditions and the visible settlement. First, AP Soil 600, a single-component polyurethane product designed for soil stabilization and permeation, would be injected to densify the loose soil beneath the affected slabs. Following soil treatment, two-component polyurethane foam, AP Lift 475, would be used to lift the settled concrete sections back to their proper elevation. This non-invasive approach would eliminate the need for demolition and replacement of concrete, allowing for minimal disruption to building operations while providing a long-lasting solution.

Procedures

1. Technicians established injection points in a grid pattern, spacing them approximately 3-4 feet across the affected areas.
2. Saw cuts were made at key joints to free slabs from binding against adjacent concrete, allowing for controlled lifting without creating additional stress.
3. In the initial phase, AP 600 was injected through small drilled holes to stabilize the underlying soil and prevent future settlement.
4. After the soil stabilization phase, AP 475 was injected in multiple passes, starting from the areas closest to the building and moving outward.
5. Elevation was carefully monitored throughout the lifting process using zip levels and dial indicators to ensure proper alignment and prevent cracking.

Results

The rehabilitation project restored proper elevations at all transition points around the building, eliminating tripping hazards and improving aesthetics and safety. The lightweight polyurethane material added minimal load to the treated areas while effectively compacting and stabilizing the underlying soil.

From a financial perspective, this approach delivered significant cost savings compared to traditional repair methods. Concrete replacement would have required demolition, disposal, and new concrete installation, which is why the two-phased remediation project resulted in a 90% reduced cost compared to traditional replacement methods.

Want more information on geotech products?

A property in Atlanta featured a multi-level parking structure with a split-level design. The upper-level parking area began showing signs of significant distress, with visible cracking and pavement deterioration. Investigation revealed that soil was actively migrating through a lower retaining wall of the parking structure, creating voids behind the wall and compromising support for the pavement above. The color change in the asphalt surface clearly marked the affected area, and the problem was getting progressively worse, posing both functional and safety concerns for vehicles using the facility.

Initial Assessment

Engineers determined that soil was passing through the precast concrete retaining wall that separated the lower parking level from the surrounding earth. Testing revealed substantial voids had formed behind the wall, primarily involving clay soils that had become soft and unstable. While the wall itself remained structurally sound, the continued migration of soil threatened to create more significant issues if left untreated. Traditional repair methods would have required extensive excavation and potential wall replacement, a prohibitively disruptive and expensive approach for an active parking facility. The challenge was stabilizing the soil and filling the voids without impeding parking operations.

Proposed Solution

Alchatek recommended using two-component polyurethane foam (AP Lift 475) to stabilize the soil and fill the voids behind the wall. This material was selected specifically because of its high compressive strength and ability to effectively fill large voids in clay soil conditions. Since the wall was precast concrete and structurally sound, there was no concern about the polyurethane's strength pushing or damaging the wall. The expansive properties of the material would ensure complete penetration into irregular void spaces, while its closed-cell structure would prevent future water migration that could cause additional soil loss. This approach would stabilize the subsurface conditions without requiring excavation or disrupting the facility's operations.

Procedures

1. Established a precise injection grid with tighter three-foot spacing in the first row close to the wall and slightly wider spacing in the second row.
2. Drove injection pipes through the soil to reach the void areas behind the wall.
3. Injected approximately 15 pounds of two-component polyurethane every 1.5 feet vertically, ensuring complete filling from bottom to top.
4. A hydraulic pipe puller was used to extract injection pipes during material placement for controlled distribution.
5. Monitored for any structural movement throughout the process using zip levels and dial indicators to prevent over-pressurization.
6. Injected material systematically across the affected area, adjusting quantities based on observed soil conditions.

Results

The project successfully halted soil migration through the retaining wall and stabilized the pavement above. The two-component polyurethane effectively filled all voids while creating a waterproof barrier to prevent future erosion. Most importantly, the solution eliminated the need for disruptive and costly excavation, allowing the parking structure to remain operational throughout the repair process. Post-treatment monitoring showed complete stabilization with no further signs of settlement or cracking in the pavement. The property owner avoided significant reconstruction costs that would have been incurred with traditional methods, while also preventing potential revenue loss from parking facility closure. This case demonstrates how polymer injection technology can provide effective structural solutions with minimal operational impact, a key consideration for commercial property remediation.

Want more information on geotech materials and equipment?

US Highway 98 is the main coastal route along Florida’s panhandle, connecting Panama City Beach, Destin, and Fort Walton Beach. Over time, the Florida Department of Transportation (FDOT) faced persistent issues with groundwater infiltrating the stormwater system. This infiltration carried exceptionally fine “sugar sand” into pipes and manholes, gradually reducing capacity and causing flooding on roadways during heavy rains. The situation escalated when a vehicle was damaged after falling into a void created by soil loss beneath the roadway, highlighting the urgent need for a lasting solution.

Initial Assessment

Inspections found that groundwater was entering through pipe joints, manhole connections, and cracks in concrete structures, transporting fine sand and creating sizable voids beneath the infrastructure. The affected system included concrete pipes ranging in diameter from 36 to 84 inches, with numerous manholes spread along a three-mile stretch of highway. Traditional repair would have required full excavation and replacement—a disruptive and prohibitively expensive process for such a critical transportation corridor. Based on the extent of sand loss and the depth of infrastructure, voids were estimated to range from several inches to several feet around key structures.

Proposed Solution

Alchatek recommended Spetec PUR H100, a semi-rigid polyurethane grout, for comprehensive rehabilitation. This material was chosen for its ability to expand and fill voids, while remaining flexible enough to accommodate minor ground movement and maintain a watertight seal. The approach involved direct injection into leaking joints and cracks, followed by creating a curtain wall around critical structures to prevent further sand migration and stabilize the surrounding soils. FDOT required a five-year warranty on the repair, underscoring both the severity of the problem and their confidence in the solution.

Procedures

1. Technicians drilled directly into each pipe joint, installing injection ports for precise placement of H100 grout.
2. Additional holes were drilled about one foot from each joint in a clock-pattern to encapsulate the joints and stabilize the surrounding soil.
3. Injection began at the lowest point of each structure and progressed upward to ensure complete filling and displacement of water.
4. Manholes received perimeter injections to form a waterproof curtain wall, with special attention to all pipe penetrations.

Results

Over the course of 18 months, approximately 2,000 pipe joints and numerous manholes were treated along a three-mile stretch of US 98. Since the project's completion in 2017, there have been no warranty claims or reported issues, even during multiple heavy storm seasons. The highway has remained free of flooding and sand accumulation, and no further undermining of the roadbed has occurred. By choosing polyurethane injection over full excavation, the FDOT avoided estimated replacement costs of $7 million to $16.5 million, while keeping the highway open and safe throughout the process.

Want more information on leak seal products and equipment?

The US Army Corps of Engineers (USACE) required a solution to fill the annular spaces between eight 84-inch ductile iron pipes and the concrete bulkhead at a new pump station along the Mississippi River in Port Sulphur, Louisiana. Traditional methods, such as pouring non-expanding resin, were cost-prohibitive (approximately $50,000 per void) and lacked the necessary performance characteristics. The voids posed a risk of instability and water infiltration, demanding a material that combined strength, adhesion, and environmental safety.

Initial Assessment

Inspections revealed significant annular gaps around the pipes, necessitating a material that can bond to both ductile iron and concrete while forming a waterproof seal. The USACE prioritized a solution that avoided excavation, minimized downtime, and provided long-term durability. Based on the scale of the pipes and typical annular space requirements, the voids were estimated to range from 6 to 12 inches in width around each pipe, although exact dimensions would depend on site-specific conditions.

Proposed Solution

Alchatek’s AP Lift 430, a high-density, two-component polyurethane foam, was selected for its compressive strength of 7,200 psf, ensuring structural support while adhering tightly to both ductile iron and concrete. Its hydrophobic nature prevents water infiltration,  and its expansion capability allows for complete void filling without precise volume calculations. AP Lift 430 provided a balanced solution for strength, durability, and cost efficiency.

Procedures

1. Material Application: AP Lift 430 was free-sprayed into the annular spaces using a Graco Fusion spray foam gun, ensuring deep penetration and adhesion to both the ductile iron pipes and the concrete bulkhead.
2. Curing and Expansion: The foam expanded to fill the voids, creating a seamless and waterproof barrier.
3. Surface Finishing: Excess foam was ground flush with the concrete surface to allow secure installation of flanges and gaskets.

Results

The project was completed in two days, with no disruptions to ongoing site operations. AP Lift 430 formed a durable, watertight seal, meeting all USACE requirements for strength and longevity. Total material costs were approximately $30,000, representing a 90% cost savings compared to other resin-based alternatives. The USACE supervisor conducted daily inspections and praised the efficiency and quality of the repair.

Want more information on geotechnical products and equipment?

Alchatek proudly supports the Wounded Warrior Project, a nonprofit founded in 2003 to empower post-9/11 veterans with physical or mental injuries, along with their families and caregivers. Its mission is to create the most successful, well-adjusted generation of wounded service members in U.S. history.

Wounded Warrior Project - Origins

The Wounded Warrior Project began in Roanoke, Virginia, when Marine Corps veteran John Melia, injured in a 1992 helicopter crash, saw the needs of returning Iraq and Afghanistan veterans. He and his friends raised $5,000 to deliver backpacks with essential supplies to wounded soldiers at Walter Reed Army Medical Center. From this small act, the Wounded Warrior Project grew into a national organization offering comprehensive support.

Wounded Warrior Project - Services

• Mental Health Support: Workshops, retreats, and counseling to build resilience and community, helping veterans feel less isolated.
• Physical Wellness Initiatives: Adaptive sports, cycling events, and wellness challenges to promote rehabilitation and camaraderie.
• Financial Guidance: Career advice, job placement, and benefits counseling to ensure economic independence.
• Support for Severely Injured Veterans: Ongoing assistance for injured veterans and caregivers, including a resource hub for personalized service connections.

Through partnerships and advocacy, the Wounded Warrior Project drives veteran-friendly policies and collaborates with organizations to expand care. Veterans credit it with transformative opportunities, from adventures to career growth.

Alchatek is deeply honored to have supported this vital mission for over 10 years. In recognition of our commitment, we were humbled to receive a challenge coin from the Wounded Warrior Project, a symbol of our shared dedication to those who’ve served our nation.

Join us in making a difference - click the button below to donate today.

Alchatek is pleased to announce the promotion of Andrew D. Powell to the role of Vice President of Sales. Previously, Business Development Manager, we congratulate Andy on his new executive position in recognition of his extensive experience and contributions to the company's growth since joining us.

With extensive experience in manufacturing, application, equipment, estimating, field service, and training for the entire product line, Andy has worked with many clients, including several state departments of transportation and high-profile institutions such as the Army Corps of Engineers, Duke Energy, and Florida Power and Light. Andy attended Georgia Tech and Auburn University and is well-equipped to succeed in his new position as Vice President of Sales.

Alchatek Chief Executive Officer Stephen Barton comments on the promotion, "Andy has been a leader in our organization for over 12 years, and we are looking forward to his continued leadership in his role as Vice President of Sales. Andy will be the primary driver of our bold new strategy as we expand our product and service offerings in the coming years."

Want more information on Alchatek products?

Initial Assessment

The team at PURLevel was contacted regarding significant floor settlement issues at Outpost Harley-Davidson in Pueblo, Colorado, where a water pipe rupture had resulted in concrete movement and void spaces beneath the floor. The affected areas showed uneven surfaces with depressions ranging from 0.25 to 3 inches, creating hazards for both foot and equipment traffic.

Proposed Solution

AP Lift 430 polyurethane foam was selected for this project due to its excellent void-filling and lifting capabilities. With its 22x expansion capability and 7,200 psf compressive strength, this material is ideal for commercial floors supporting heavy equipment like that found in a motorcycle dealership.

Procedures

1. Site Preparation

   • The affected area was thoroughly inspected to determine the full extent of damage.
   • A 5'x5' grid pattern was marked across the entire interior floor area.

2. Grid Injection

   • Strategically placed injection points were established following the grid pattern.
   • Holes were drilled through the concrete slab at each injection point.
   • Polyurethane foam was systematically injected to fill voids beneath the slab.

3. Lift and Stabilization

   • After initial void filling, additional injections were performed to lift the sunken areas gradually.
   • An incremental lifting approach was used to prevent concrete cracking.
   • Areas requiring significant lift (up to 3 inches) received multiple injection passes.
   • Levels were continuously monitored to ensure even lifting across the floor surface.

Results

The project successfully stabilized the Outpost Harley-Davidson floor and restored it to its proper level. The comprehensive void-filling addressed the underlying instability caused by the water pipe rupture, providing a solid foundation for the concrete slab. Success was evident in the restored functionality of the dealership floor and the elimination of safety hazards posed by the uneven surface.

Want more information on leveling concrete slabs?

Concave ports, for use with PX-7 Slab Lifting Guns, offer enhanced performance for concrete lifting with their unique dimple top and black sealing sleeve for a secure fit. Their durable design ensures reliability under tough conditions, while the sleeve's ability to seal directly to concrete minimizes leaks and boosts efficiency, reducing the need for frequent port replacement due to leakage. 

Features

• Dimple top.
• Includes black sealing sleeve.

Benefits

• Durable design ensures enhanced reliability.
• Sleeve seals to concrete.

Requires a standard gun clamp.
Available in bags of 100.

Want more information on geotech materials and equipment?

Attention Geotech Professionals!

Alchatek is exhibiting at the DFI S3: Slopes, Support and Stabilization Conference.

Where: Madison Marriott West in Madison, Wisconsin

When: August 5–7, 2025

Click Here for Registration Info

Visit us at Booth 302 to explore our advanced polymer solutions, including single and two-component polyurethanes for soil stabilization, groundwater control, and deep foundation support, addressing challenges like unstable slopes, soft ground, and deep excavation shoring for geotechnical projects.

Learn How Alchatek Helps You

At Booth 302, you can meet with our experts to learn how Alchatek empowers your geotechnical projects with cutting-edge technologies.

We support geotech professionals in three key ways:

• Innovative Polymer Solutions: Our advanced polyurethane grouts and foams provide robust solutions for curtain grouting, point grouting, and ground improvement, ensuring stability for slopes, excavations, and deep foundations.
• Expert Technical Support: We offer comprehensive training and ongoing assistance, leveraging our proven track record with industry leaders to optimize your project outcomes.
• Environmentally Safe Materials: Our NSF/ANSI/CAN 61-certified, chemically inert polymers ensure safety and compliance in sensitive environmental areas.

Want more information on Alchatek products?

Buchanan Dam, located on the Colorado River in Texas, is a critical infrastructure built in 1937 to form Lake Buchanan. The dam is one of the longest multiple-arch dams in the world and serves as a vital resource for hydropower generation and flood control. Over time, the dam developed high-pressure water leaks in its concrete arches, particularly in Arch 47. These leaks were exacerbated by seasonal temperature fluctuations, which caused thermal expansion and contraction, leading to recurring cracks and water infiltration. Restek, Inc., a contractor specializing in structural repairs, collaborated with Alchatek to implement a polyurethane grouting solution to address these issues.

Initial Assessment

An inspection of the dam revealed severe water infiltration concentrated in Arches 45-47. Arch 47 presented the most aggressive leaks, with water flowing under high pressure. Previous injection efforts had only provided temporary relief due to insufficient grout penetration and equipment limitations. The concrete structure’s thickness and seasonal movement posed additional challenges for effective leak sealing.

Proposed Solution

Alchatek recommended using a combination of advanced polyurethane products tailored to the dam’s specific conditions. Spetec PUR HighFoamer was selected for high-pressure leaks due to its rapid reaction time and expansive properties. Spetec PUR H100 and Spetec PUR F1000 were chosen for lower-flow areas requiring flexibility to accommodate joint movement. Higher-capacity airless pumps, such as the Titan 640 and Titan 8900, were utilized to ensure effective grout delivery.

Procedures

1. Preparation:

• To reach the midpoints of the concrete structure, deeper injection points were drilled using 24-inch and 36-inch masonry drill bits.
• Oakum rope saturated with grout was packed into joints to slow water flow during the injection.

2. Injection Process:

• Spetec PUR HighFoamer mixed with Alchatek Gen Cat was injected into high-flow leak areas using upgraded pumps capable of handling high pressure.
• Flexible grout mixtures (Spetec PUR H100/PUR F1000) were injected around rigid plugs to reinforce sealed areas and accommodate seasonal joint movement.

3. Post-Sealing Monitoring:

• The team monitored material expansion within cracks and adjusted injection pressure as necessary to ensure complete sealing.

Results

The grouting crew successfully sealed leaks throughout Arches 45-47. High-flow leaks in Arch 47 were effectively stopped using Spetec PUR HighFoamer, while lower-flow leaks were addressed with flexible polyurethane grout mixtures. Equipment upgrades allowed deeper injections, overcoming previous limitations and ensuring long-term durability against thermal stresses. Subsequent inspections confirmed substantial reductions in water infiltration, with no major leak recurrence reported.

Conclusion

The Buchanan Dam leak-sealing project demonstrated the importance of combining advanced materials with appropriate equipment upgrades to address complex infrastructure challenges. Restek, Inc.'s collaboration with Alchatek resulted in a sustainable repair strategy that restored the dam’s structural integrity while accommodating environmental factors such as temperature fluctuations. This case underscores polyurethane grouting’s effectiveness as a solution for high-pressure leak repair in large-scale concrete structures.

Want more information on polyurethane leak seal materials?