Alchatek Blog

A fire station access roadway developed cracking from subsurface voids caused by storm drain seam gaps that washed out soil during heavy rain, threatening daily emergency operations and pavement integrity. Geotech specialists from Helicon were brought in to assess the situation.

Initial Assessment

CCTV and probing identified voids up to several inches beneath the asphalt and open joints along the drain, allowing soil migration. Excavation replacement was rejected due to weeks-long closure risk, higher cost, and potential future seam misalignment, making trenchless permeation grouting the viable path.

Proposed Solution

AP Fill 700 was chosen for hydrophobic, single‑component injection with very low viscosity, and adjustable cure, enabling soil permeation, joint sealing, and formation of a water‑tight bearing layer for traffic.

Procedures

1. Map defects and mark the injection grid along the pipe and pavement.
2. Drill ports; set packers to target joints and halo around pipe.
3. Inject AP Fill 700 to refusal, prioritizing seam sealing.
4. Permeate surrounding soils to fill voids and densify subgrade.
5. Monitor pressures/returns; adjust set times for water presence.
6. Verify with sounding/CCTV and traffic proof-load.

Results

• Restored structural support and sealed joints with zero operational downtime.
• Completion in days vs weeks.
• Approximately 95% cost savings compared to full excavation and pipe replacement.

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Attention Geotech Professionals!

Alchatek is exhibiting at the DFI 50 conference in Nashville.

Where: Gaylord Opryland Resort & Convention Center

When: October 20-23, 2025

Click Here for Registration Info

Visit us at Booth 227 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 227, 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.

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A multi-level parking facility in downtown Los Angeles was experiencing significant water infiltration through its concrete ceiling. Building management had noticed increasing water staining and active leakage, particularly following rain events. The water migration around electrical conduits and light fixtures was most concerning, creating potential safety hazards with the electrical systems. Previous attempts to seal the ceiling using conventional surface treatments had failed to resolve the issue. With the structure serving high-end retail clients, the property management company required a solution to effectively stop the leaks while minimizing disruption to the facility's daily operations.

Initial Assessment

Inspection revealed that water was infiltrating through microscopic pathways in the concrete, with particularly noticeable intrusion around embedded conduits and penetrations. Engineers determined that concrete shrinkage had created tiny void spaces around these penetrations, some measuring only thousandths of an inch. Water was following these pathways, traveling along the outside of conduits and emerging at light fixtures and junction boxes installed in the ceiling. The ceiling showed distinctive water staining patterns radiating from these fixtures, confirming the migration pathway. Traditional polyurethane grouts would be too viscous to effectively penetrate these extremely small void spaces, requiring a material with exceptional flow characteristics.

Proposed Solution

Alchatek recommended using a specialized acrylic resin, Spetec AG 200. This material was selected specifically because of its extraordinarily low viscosity, significantly thinner than polyurethane alternatives, allowing it to travel through microfractures and voids that water could penetrate. Unlike thicker injection materials, acrylic resin can follow the same migration pathways as water, creating a waterproof barrier precisely where needed. The material's ability to travel long distances from injection points would minimize the number of injection ports required, reducing ceiling penetrations while ensuring complete sealing coverage around electrical conduits and other vulnerable areas.

Procedures

1. Technicians identified and mapped all water intrusion points in the ceiling, identifying migration patterns to determine optimal injection locations.
2. Strategic drilling and port installation were performed at intervals designed to intercept the water pathways, with particular focus on areas around electrical conduits.
3. Ports were installed in a pattern that would allow the low-viscosity material to flow along the same paths as the water infiltration.
4. Acrylic resin was injected through the ports, with continuous monitoring for material appearance at distant locations.
5. Injection continued at each port until the material was observed emerging from adjacent ports or known leak points, confirming pathway filling.
6. Engineers carefully monitored electrical systems throughout the process to ensure no disruption to the building's operations.

Results

The injection program successfully sealed the water infiltration pathways throughout the parking structure ceiling. Post-treatment monitoring through several significant rain events confirmed that all previously active leaks had been eliminated, with no further water migration observed around electrical fixtures. Most importantly, the acrylic resin's exceptional flow characteristics allowed for complete sealing with minimal disruption to the facility's operation. The property management company avoided spending an estimated $80,000-$100,000 that more invasive remediation methods would have required, while eliminating potential liability from water contact with electrical systems. The parking facility remained operational throughout the repair process, avoiding revenue loss that would have resulted from traditional ceiling replacement or excavation of the deck above.

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The property manager for a multi-level parking garage contacted Pavecon regarding persistent water infiltration in an elevator pit. The facility engaged Allana Buick & Bers, Inc. to develop a remediation strategy. Water leakage in elevator pits poses risks to equipment, safety, and can lead to service disruptions.

Initial Assessment

Inspection revealed multiple water entry points in the concrete walls of the elevator pit. The recurring water infiltration threatened the elevator system's integrity and created potential safety issues. Traditional repair methods would require extensive excavation and significantly disrupt parking facility operations, making them impractical and costly. The assessment determined that an effective solution was needed to address active leaks and provide long-term waterproofing without frequent maintenance.

Proposed Solution

The team selected a specialized polyurethane injection system (Spetec PUR F400) for the elevator pit leakage. This product effectively seals active water leaks in concrete structures by creating a waterproof barrier without extensive excavation. The method required only brief elevator shutdown periods rather than extended facility closures and could be applied even with active water infiltration.

Procedures

1. Thoroughly cleaned repair areas to remove dirt, debris, and loose concrete that could compromise adhesion.
2. Drilled through the concrete wall at strategic locations to access water infiltration pathways.
3. Installed injection ports (zerk fittings) into each drilled hole to facilitate polymer application.
4. Injected water when necessary to properly activate the polyurethane foam reaction.
5. Polyurethane injection material was applied through installed ports, allowing it to expand and fill voids.
6. Performed sequential injection following a pattern to ensure complete coverage of affected areas.
7. Removed injection ports and patched drill holes with hydraulic cement after the injection process.
8. Performed final inspection to verify cessation of all leaks.

Results

The polyurethane injection process successfully sealed all water infiltration points in the elevator pit, creating a waterproof barrier. The repair was completed within the scheduled timeframe, minimizing elevator system downtime. The project addressed approximately 17 linear feet of repair work.

After several substantial rain events, the elevator pit remained completely dry, confirming the solution's effectiveness. The property manager expressed satisfaction with the results, subsequently requesting additional services at other facilities and providing positive recommendations.

This solution demonstrated significant cost advantages over traditional methods, saving an estimated 60-70% compared to conventional waterproofing approaches while preventing potential damage to electrical and mechanical components.

Want more information on leak seal material and equipment?

MixMaster Gun Cleaner 160 is the latest innovation designed to streamline maintenance for contractors using the MixMaster Pro gun for concrete slab lifting. This powerful liquid ISO and polyurethane remover simplifies the cleaning process, ensuring your equipment stays in top condition with minimal effort. Packaged for convenience and engineered for efficiency, this cleaner delivers rapid results, enabling professionals to focus on the job rather than on time-consuming maintenance. 

Features

• Packaged in a convenient 5-Gallon pail.
• Dispensing gun and pump included with purchase of the full kit.

Benefits

• Larger quantity than brake cleaner.
• As easy to apply as brake cleaner.

MixMaster Gun Cleaner 160 from Alchatek is more than just a cleaning solution—it’s a productivity booster for contractors who value efficiency and reliability. By offering a larger quantity and ease of application comparable to brake cleaner, this product ensures your MixMaster Pro gun remains free of stubborn ISO and polyurethane residue, reducing downtime and maintenance costs. Pair it with Alchatek’s industry-leading polyurethane foams and equipment for a seamless, high-performance slab lifting experience.

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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.

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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.

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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.

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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.

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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.