Alchatek Blog

Gerace Construction undertook a gate replacement project at the Tom Miller Dam in Austin, Texas. While working on Large Gate #6, and after installing a needle beam cofferdam system to lower the water level, a continuous wet spot was discovered under the metal gate sill. This indicated a crack in the concrete extending under the sill plate. Sealing the leak was necessary to prepare and coat the steel sill plate, which was crucial for the overall gate replacement.

Initial Assessment

The primary challenge was water seeping through a crack, less than one linear foot in length, located in the concrete beneath the steel gate sill. The cofferdam system had created approximately 18 feet of head pressure upstream, with the water level pumped down about two feet below the sill. As per the project specifications, a dry surface was required to apply coatings to the steel sill plate.

Proposed Solution

Alchatek recommended Spetec PUR H100 to seal the crack. This hydrophobic polyurethane resin was chosen for its ability to rapidly seal cracks with reasonable water flow and minimal anticipated movement. The solution involved injecting the resin into the crack to create a watertight seal, allowing the steel surface to dry for coating application. Alchatek also provided an on-site representative during the injection process, as required by the project specifications.

Procedures

1. Preparation:

• The contractor established the cofferdam system and lowered the water level to expose the leaking area.
• Injection ports were installed along the crack at 12-inch centers on alternating sides.

2. Injection Process:

• Spetec PUR H100 mixed with Alchatek Gen Cat was injected into the crack using positive displacement equipment capable of maintaining a minimum pressure of 250 psi.
• Injection began at the lowest port and continued sequentially upward until grout filled the crack and seepage ceased.
• Inline pressure was monitored throughout to ensure it did not drop below 190 psi during injection.

3. Post-Injection:

• The injected resin was allowed to cure fully, forming a watertight seal.
• Excess surface seal material was removed, and the repaired area was inspected to confirm no further water intrusion.
• The injection ports were removed, and holes were patched flush with hydraulic cement as per project guidelines.

Results

The application of Spetec PUR H100 successfully sealed the leak under the steel gate sill, allowing Gerace Construction to proceed with surface preparation and coating application. The fast-reacting properties of Spetec PUR H100 minimized delays while ensuring long-term durability against water infiltration. The Lower Colorado River Authority (LCRA) engineering staff approved of the product, and the Alchatek representative provided the required on-site supervision ensured compliance with all quality assurance measures, resulting in a successful repair that restored functionality and structural integrity to Gate #6 at Tom Miller Dam.

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Gerace Construction was contracted for a project at the Pat Mayse Dam in Paris, Texas, to repair and seal leaks in the discharge conduit. The project involved addressing cracks and weeps within a concrete pipe structure. The United States Army Corps of Engineers (USACE) was overseeing the project, requiring strict adherence to specifications, including the presence of a manufacturer’s representative on-site during the grout injection process.

Initial Assessment

The primary challenge was to stop active water leaks within the concrete conduit pipe. A site visit identified the locations of cracks and weeps, as documented in the photo report included in the specification. The photos showed typical leaking monolith joints on the sides and top of the structure, as well as leaking monolith cracks. These leaks required a solution that could effectively seal actively flowing water in both vertical and horizontal orientations.

Proposed Solution

Alchatek proposed the use of Spetec PUR F400, a flexible polyurethane grout, to address the leaking cracks. This product was selected for its ability to penetrate narrow cracks, its flexibility to accommodate movement, and its compatibility with wet concrete surfaces. The plan included supplying the necessary materials, equipment, and a qualified manufacturer’s representative to supervise the installation.

Procedures

1. Preparation:

• Injection ports were installed along the identified cracks and weeps in the concrete pipe.
• Holes approximately 12 inches deep were drilled at a 45-degree angle.

2. Injection Process:

• Spetec PUR F400, along with Alchatek Gen Cat to control reaction time, was injected through the installed packers using a suitable pump.
• Injection began at the lowest packer for vertical joints or cracks, working upwards.
• The process continued until the grout traveled between packers, and the leaks were sealed.
• An approved epoxy adhesive paste was used to seal the surface of the cracks, allowing grout to travel.

3. Post-Injection:

• Re-injection was performed to ensure all voids were properly sealed off.
• Each installed packer was re-injected with a small amount of water to allow the resin in the drill hole to react.
• The injection ports were removed and cut flush, and packer holes were filled with approved epoxy paste.
• Once cured, the remaining materials were removed from the concrete surface with a wire brush or handheld grinder.

Results

The Alchatek solution, implemented by Gerace Construction, effectively sealed the cracks and stopped the leaks in the Pat Mayse Dam discharge conduit. The on-site presence of a qualified manufacturer’s representative ensured the proper application of the product, meeting the requirements of the USACE. The project was completed in accordance with the specifications, resulting in a successful repair and improved structural integrity of the dam’s discharge conduit.

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The City of Sand Springs, Oklahoma, identified a foundation leak in Bay 10 of the Shell Lake Dam, necessitating repairs to ensure the dam’s structural integrity. The city’s Public Works Department contracted with a qualified firm to address the issue, and Keithline Engineering Group was retained to provide engineering design and oversight for the project.

Initial Assessment

An inspection by Keithline Engineering revealed an active boil, or leak, in the concrete footing of Bay 10. The leak, measuring approximately 5” by 7”, exhibited increasing water movement and was deemed a priority for repair. The engineering team determined that the water was likely traveling between the concrete footing and the porous sandstone underlayment before exiting through the hole in the concrete. This leak was transporting a small amount of material under low pressure. It was also determined the owner had made prior unsuccessful attempts to seal the area with bentonite.

Proposed Solution

After consulting with Alchatek, Keithline Engineering specified a leak-sealing solution centered around the injection of Spetec PUR H100. Alchatek recommended this hydrophobic polyurethane grout for its ability to expand and create a dense, impermeable seal upon contact with water. The repair strategy involved drilling through the concrete and injecting the grout into the concrete/sandstone interface to create a grout curtain. This approach aimed to stop the leak at its source and prevent further water migration.

Procedures

1. Preparation:

• Hammer-drilled 1/2-inch injection ports were installed into the concrete foundation at designated locations.
• Saturated oakum rope or hydraulic cement was applied to temporarily plug the hole during the injection.

2. Injection Process:

• Spetec PUR H100 was injected through installed packers using positive displacement pumps.
• Injection proceeded until the grout formed a complete polyurethane barrier around the boil and stopped water infiltration.
• The process included monitoring grout expansion and ensuring proper confinement within the concrete/sandstone interface.

3. Post-Sealing:

• Following the injection, all nipples were removed, and drilled holes were patched with hydraulic cement to a minimum depth of 12 inches.

Results and Conclusion

The injection grouting successfully sealed the foundation leak in Bay 10 of Shell Lake Dam. Spetec PUR H100 formed a durable polyurethane barrier, effectively stopping water flow and preventing further erosion of material from beneath the dam footing. The swift and effective repair was achieved in a matter of hours. Restek, Inc. precisely executed the specifications. The result is a solution that preserves the long-term structural integrity of the Shell Lake Dam, showcasing the value of proactive maintenance in preserving critical water resources.

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A Utah-based geotech specialist partnered with a general contractor to address a critical DOT infrastructure challenge involving the replacement of an existing culvert on a major roadway in Utah. The project involved the installation of precast concrete slabs on both sides of the box culvert, designed to create a seamless transition from the culvert to the compacted road base.

Site Investigation and Challenge

During the design phase, engineers identified that constructing a compacted road base beneath the slab would inevitably leave voids underneath. These voids posed a risk of uneven support and potential rocking of the slab when subjected to heavy traffic load.

Proposed Solution

To address this, ¾” holes were drilled four feet apart to allow for injection rods to be inserted through the slab. The foam selected for this slab was AP Lift 440 structural foam due to its rapid expansion and high strength needed for DOT projects. This foam expands 17-19 times its original volume within 8-10 seconds of injection, ensuring comprehensive void filling. Dial indicators were used to ensure that there was no vertical movement of the slab during the injection process.  

Results and Conclusion

The entire operation was executed in approximately three hours, utilizing about 400 lbs of structural foam. This successful application filled all of the voids, providing uniform support for the precast slabs and enhancing overall road stability. The rapid curing properties of the foam allowed for swift project completion with minimal disruption to traffic.

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Suburban Basement was hired to address significant voids beneath a slab foundation residence in Roseville, Michigan. The voids were suspected to have been caused by a compromised sewer line under the bathroom shower, resulting in extended leakage affecting a substantial portion of the home’s foundation. After plumbers discovered the issue, a local property restoration company managing the overall project engaged Suburban Basement.

Initial Assessment

The extent of the voids was assessed using 4-foot-tall plow markers as probes. The voids almost entirely engulfed these probes, indicating severe foundation undermining. The situation required a solution that could effectively fill large voids, bond with both soil and concrete, and perform well in wet environments.

Proposed Solution

Suburban Basement proposed using Alchatek's AP Lift 430 for the void filling. This material was chosen for its high expansion rate, making it cost-effective for large voids. Its ability to bond with soil and concrete, perform in wet conditions, and displace residual moisture from the plumbing leak made it ideal for this application.

Procedures

1. Drilled a systematic grid pattern of holes throughout the residence
2. Employed controlled injection shots to avoid excessive product usage and prevent lifting
3. Carefully filled all voids without causing any lifting of the foundation

Results

The project restored the foundation's integrity, filling all voids within a day. This efficient execution led to significant time and cost savings for all parties. The insurance company reduced relocation expenses, the restoration company delivered ahead of schedule, and the homeowners returned to their structurally sound homes earlier than expected. The outcome satisfied all stakeholders, demonstrating the effectiveness of the chosen solution in addressing complex foundation issues promptly and efficiently.

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An old farmhouse with a wrap-around porch in Lake Orion, Michigan, presented a unique challenge. Beneath the porch lay an old cellar, initially used for coal storage but now serving only as a conduit for a well line into the residence. The primary concern was the inward buckling of the cellar walls, which posed a significant safety hazard. Many contractors suggested demolishing the porch and excavating the cellar, a solution that would have incurred substantial costs for both demolition and reconstruction.

Initial Assessment

Suburban Basement was engaged to address this issue. Upon evaluation, the team identified a more cost-effective and less invasive solution. The cellar, measuring 12 feet in length, 5 feet in height, and 5 feet in width, could be filled with foam to mitigate the risk of further wall collapse. This approach would spare the property owner the expensive and disruptive process of demolition and reconstruction.

Proposed Solution

The team proposed filling the cellar with Alchatek’s AP Lift 430 foam. This material was chosen for its extensive expansion rate, superior compressive strength, and lower application temperatures. These properties allowed for quicker application intervals while maintaining optimal temperatures between applications and minimizing ignition risks.

Procedures

1. Encapsulated the well line with sonotubes elevated above the cellar floor, ensuring future accessibility.
2. Installed OSB sheathing to define foam boundaries and prevent overflow.
3. Applied AP Lift 430 in layers, allowing cooling intervals between applications to optimize expansion and stability.
4. Coordinated with masons to prepare for CMU block installation at the containment boundary, ensuring seamless alignment with the existing foundation.

Results

The foam-filling solution successfully stabilized the cellar walls, eliminating the collapse risk while preserving functionality. Compared to traditional approaches, this method saved the client approximately $25,000 and maintained the home’s historic features. Completed in just five days, the project significantly outpaced conventional methods. Homeowners were highly satisfied with the noninvasive approach, cost savings, and seamless integration with their property’s historic character, demonstrating the effectiveness of innovative techniques in addressing complex structural challenges in historic properties.

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Suburban Basement was contracted to address a multifaceted water intrusion issue on a Rochester Hills, Michigan property. The basement had water ingress from both the furnace ductwork and the foundation. The ductwork, extending through the foundation wall into a garage-adjacent wall cavity, had sections below grade behind a garage curb. The root of the problem was water pooling under the back curb, caused by settled garage slabs from the main vehicle entrance.

Initial Assessment

The project was divided into two phases: first, addressing the leaking foundation and furnace ductwork, and second, void filling and concrete leveling of the garage floor and curb. The complexity arose from the undermined garage slabs and the need to prevent water intrusion while ensuring the safety of the furnace ductwork.

Proposed Solution

For the initial water intrusion, Suburban Basement proposed using Alchatek’s Spetec PUR Highfoamer for curtain grouting, given the limited accessibility and its fast reaction time. For the concrete leveling and void filling, AP Lift 430 was selected due to its expansion rate, soil stabilization capabilities, water displacement properties, and quick curing time for vehicle traffic.

Procedures

1. Applied curtain grout to the positive side of the wall to stop water intrusion and encapsulate the dual wall furnace ductwork
2. Commenced void filling and leveling at the garage curb, progressing toward the main vehicle entrance
3. Filled all voids beneath the garage curb and leveled the concrete across all areas of concern
4. Conducted water tests to ensure all leaks were addressed before proceeding to phase two
5. Performed void filling and concrete leveling, displacing significant amounts of water near the main vehicle entrance

Results

The project was completed successfully in two phases, with the curtain grouting finished within hours and the void filling and concrete leveling taking approximately half a day. All leaks were effectively stopped, and the concrete was successfully leveled. The homeowner expressed high satisfaction, notably as previous repair attempts had failed. Suburban Basement’s solution not only resolved the immediate water intrusion problems but also extended the lifespan of the garage concrete and driveway, providing a comprehensive fix to a complex issue.

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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.

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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.

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A broadband provider in Alpharetta, Georgia, contacted a local leak seal contractor after discovering water infiltration through a crawl space wall during heavy rainstorms. Over time, cracks had developed, allowing not only water but also sediment to enter, creating substantial voids outside the fissures upon inspection. Given the sensitivity and high value of the equipment housed within the facility, eliminating all potential leaks in the crawl space became a top priority.

Powerful Polymers

The technicians chose Alchatek’s Spetec PUR HighFoamer to address this leak. This highly expansive polyurethane grout creates a robust, waterproof barrier, effectively sealing a wide variety of leaks without extensive excavation. Spetec PUR HighFoamer’s remarkable expansion capacity (40x-50x) ensures comprehensive coverage and a tight seal, making it ideal for projects requiring minimal downtime. Its NSF 61 certification guarantees safety for potable water applications, positioning this product as a versatile and cost-effective choice for leak sealing projects across various industries.

Painless Procedures

The repair process consisted of three efficient steps. First, the crew drilled through the concrete wall, installing zerk fittings into each hole for subsequent injections. Next, they used an electric airless sprayer to inject water into each fitting, ensuring proper activation of the foam. Finally, they injected Spetec PUR HighFoamer through these fittings. This created a curtain wall of polyurethane foam that effectively sealed the cracks, prevented further water ingress, and filled voids in the soil substrate.

Rapid Results

Within 24 hours, the technicians successfully sealed all leaks in the underlying crawl space. This injection process was completed in a fraction of the time required for a full membrane replacement. Months after the repair, following several heavy rainstorms, the facility manager confirmed that the crawl space has remained completely dry, with no recurrence of leaks.

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