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 Cave Buttes Dam, located in Phoenix, Arizona, required modifications that involved installing a 60-inch diameter steel conduit pipe beneath the dam through bedrock. During tunneling operations, a 15-foot-wide fault zone containing water and composed of clay was encountered. After the excavation and grouting of the annular space between the pipe and the rock with cementitious grout, leaks began to emerge from some of the welded grout packer plugs. SSC Underground was the contractor for this project, with engineering oversight provided by AECOM and the U.S. Army Corps of Engineers.

Initial Assessment

The primary issue was leaking grout plugs, which were 2-inch diameter, straight-threaded plugs welded into place after the initial grouting process. These plugs exhibited varying degrees of water seepage, with flow rates estimated at a few gallons per minute. The leaks were attributed to anticipated movement between the steel pipe and the surrounding rock due to temperature changes and vibrations. Based on these conditions, a flexible chemical grout was determined to be the best solution to seal the leaks while accommodating future movement.

Proposed Solution

Alchatek recommended injecting Spetec PUR F400, a flexible polyurethane grout, to seal the leaks. This grout was selected because of its ability to bond effectively while maintaining flexibility to withstand differential movement between the steel pipe and surrounding materials. The plan involved drilling into the existing grout plugs and injecting Spetec PUR F400 through packers to confine the grout and ensure a complete seal. The project utilized packers for controlled injection and a Titan Impact 440 pump to deliver the grout. Alchatek Gen Cat was used to manage the grout’s reaction time based on the specific site conditions.

Procedures

1. Preparation:

• The team drilled into the center of each leaking grout plug to create access points for injection.
• Packers were installed into these drilled holes to facilitate the controlled injection of the grout.

2. Injection Process:

• Spetec PUR F400 was injected through the packers using a Titan Impact 440 pump.
• Alchatek Gen Cat was added to the grout mixture to adjust reaction times as needed.
• The injection process was monitored to ensure proper confinement of the grout within the leaking areas.

3. Post-Repair Monitoring:

• After sealing each leaking port, inspections were conducted to confirm the cessation of water infiltration.
• New leaks that emerged from previously sealed or new locations were identified for subsequent treatment.

Results and Conclusion

The initial injection process sealed most of the identified leaking grout ports, effectively stopping water infiltration at those locations. However, water subsequently found new paths, resulting in additional leaks from previously sealed ports. The team used the same materials and procedures to address these additional leaks through follow-up injections. Ultimately, all leaks were successfully sealed, restoring the integrity of the steel pipe installation.

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Attention Engineers!

Alchatek is exhibiting at the International Conference on Transportation & Development and the International Airfield & Highway Pavements Conference, held at the Renaissance Phoenix Glendale Hotel & Conference Center, 9495 Entertainment Boulevard, Glendale, Arizona 85305, from June 8–11, 2025. Visit us at Booth 201 to explore our advanced polymer solutions, including two-component structural polyurethanes for concrete leveling and void fill and one-component polyurethanes for soil stabilization and leak seal, addressing infrastructure challenges like cracked pavement, sinking slabs, leaking culverts, and unstable soil for DOT and airport projects.

Learn How Alchatek Helps You

At Booth 201, you can meet with our experts to learn how Alchatek supports your infrastructure initiatives with our environmentally friendly NSF/ANSI/CAN 61-certified technologies.

We benefit engineers in three key ways:

• Connections with Experienced Contractors: We partner you with skilled, vetted contractors trained in our advanced polymer solutions for high-quality project execution.
• PDH Credit Lunch and Learn Presentations: We offer in-office presentations providing Professional Development Hours (PDH) credits, equipping your team with the latest geotechnical and infrastructure repair techniques.
• Assistance with Project Specifications: Our experts collaborate to develop precise, project-specific specifications, ensuring compliance and optimal performance.

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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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Mid South Concrete Lifting successfully executed an emergency repair operation at a Tennessee Valley Authority (TVA) lift station in New Johnsonville, Tennessee. What began as a new construction project quickly required an urgent repair when significant leakage was discovered at multiple joint locations immediately after installation. The contractor's rapid response and innovative solution prevented extensive water loss and potential environmental impacts.

Initial Assessment

The investigation began when facility managers discovered several critical issues:

• Structural weaknesses detected in multiple joint locations
• Massive water loss occurring within 24 hours of installation
• Thousands of gallons of water escaping through compromised joints
• Environmental concerns due to uncontrolled water discharge

The severity of the situation demanded emergency intervention to prevent continued water loss and potential damage to surrounding infrastructure.

Proposed Solution

After technical evaluation, Spetec PUR F400 was selected as the optimal solution due to its superior characteristics:

• Rapid-curing formulation for quick deployment
• Excellent adhesion properties for joint sealing
• Water-reactive chemistry suitable for wet conditions
• High structural strength for long-term durability
• Environmental compatibility for water infrastructure

Procedures

1. Complete dewatering of the lift station
2. Technical team rappelled into the structure
3. Systematic injection of Spetec F400 at all compromised joints
4. Progressive sealing to ensure complete joint stabilization

Results and Conclusion

The emergency repair proved successful on multiple fronts:

• Complete elimination of water loss through compromised joints
• Restoration of structural integrity to all sealed areas
• The system returned to full operational status within 24 hours
• Long-term solution achieved with minimal downtime
• Cost-effective resolution compared to alternative repair methods

The project demonstrated the effectiveness of chemical grout injection as a rapid response to critical infrastructure leaks. It successfully prevented ongoing water loss while providing a durable, long-term repair solution.

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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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Water leaks in concrete slabs can be a severe issue for property owners. These leaks occur when water from the ground seeps through cracks or gaps in the concrete foundation, leading to moisture problems inside the building. If not addressed promptly, these upward-moving leaks can lead to structural issues, damage flooring materials, and create an environment conducive to unhealthy mold growth. Curtain grouting with polyurethane is a proven technique for effectively fixing water leaks in concrete slabs. This method creates a barrier beneath the slab, preventing water from penetrating upwards and resolving the issue at its source.

The Curtain Grouting Solution

Curtain grouting is a well-established and highly effective method for addressing water leaks in concrete slabs. The process begins with drilling small holes through the concrete slab in a precise diamond grid pattern. Technicians then inject polyurethane grout into each hole, overlapping injections like shingles on a roof to ensure comprehensive coverage. Upon contact with water from the leak, the grout expands and forms a solid, watertight barrier beneath the slab. This durable seal effectively prevents further water intrusion, resolving the leak at its source.

Advantages of Curtain Grouting

This technique can address multiple leaks simultaneously, providing a comprehensive solution. Additionally, it delivers long-lasting results, ensuring the integrity of your slab for years to come. The process requires minimal equipment and causes less disruption compared to other methods. Moreover, the materials used in curtain grouting are environmentally safe and NSF-certified to meet strict environmental standards.

The Critical Role of Professional Expertise

Fixing a water leak in a concrete slab is not a task for DIY enthusiasts. Due to the complexity of the process, professional expertise is crucial. Experienced contractors possess specialized equipment and materials necessary for effective curtain grouting. Their expertise allows for accurate diagnosis of the leak's extent and location. Proper curtain grouting application requires precise techniques that professionals have honed through years of experience. Furthermore, experienced contractors provide comprehensive repairs that address not just the symptoms but the root cause of the leak.

Fixing Water Leaks in Concrete Slabs

Water leaks in concrete slabs seriously threaten your home's structural integrity. Understanding the problem and seeking professional help promptly are critical steps in addressing these issues effectively. When performed by experienced contractors, curtain grouting offers a reliable and time-tested solution to fix water leaks in concrete slabs. You can ensure your home's long-term stability and safety by taking swift action and relying on professional expertise.

Fill out this form or call 404-618-0438 for a contractor referral today!

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Aging culverts pose a significant challenge for many communities. As these vital drainage structures deteriorate, they can lead to road collapses, flooding, and environmental issues. Fortunately, culvert repair with curtain grouting offers a powerful and efficient solution to this problem. Moreover, this innovative technique can extend the life of culverts without the need for costly and disruptive excavation.

What is Curtain Grouting?

Curtain grouting is a specialized leak-sealing method. Specifically, it involves injecting water-activated resin through a leaking wall in a grid pattern. Once injected, the resin interacts with water on the other side. Consequently, it cures into a solid mass, effectively sealing the leak. This approach is particularly useful when there are many cracks or when cracks are not easily identifiable. Additionally, it proves effective in situations where traditional repair methods have failed.

The Curtain Grouting Process

The process of culvert repair with curtain grouting is straightforward yet effective. Here's a simplified overview:

1. First, technicians drill holes in a diamond pattern along the culvert wall.
2. Next, they inject grout from the bottom row upwards.
3. Subsequently, the grout flows down on the other side of the wall, creating overlapping circles of sealant and curing to stop the leaks.

This systematic approach ensures comprehensive coverage and, as a result, provides a robust seal against water infiltration.

Materials Used in Culvert Repair

Several types of resins are suitable for culvert repair with curtain grouting. These include:

• Spetec PUR H100: Offers lower expansion but more flexibility
• Spetec PUR H200: Provides high expansion with some flexibility
• Spetec PUR HighFoamer: Combines high expansion with enhanced flexibility
• Spetec AG200: Features low expansion but high flexibility and low viscosity, ideal for tight spaces

In essence, the choice of resin depends on the specific conditions of each culvert repair project. Furthermore, the versatility of these materials allows for tailored solutions to various leak scenarios.

Benefits Beyond Culverts

While this article focuses on culvert repair with curtain grouting, it's worth noting that this technique has broader applications. It's equally effective for sealing leaks in manholes, water treatment plants, catch basins, tunnels, and even basements. Therefore, this versatility makes curtain grouting an invaluable procedure in infrastructure maintenance.

A Lasting Solution for Leaking Infrastructure

Culvert repair with curtain grouting represents a significant advancement in infrastructure maintenance. A durable, flexible seal addresses the root causes of leaks and structural decay. Furthermore, it does so with minimal disruption to daily life and the surrounding environment. In conclusion, as communities grapple with aging infrastructure, this technique offers a beacon of hope for efficient, effective repairs. Ultimately, curtain grouting provides a long-term solution to the ongoing challenge of maintaining critical drainage systems.

Fill out this form or call 404-618-0438 for a contractor referral today!

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Are you a contractor looking to expand your service offerings? Consider becoming a leak seal contractor. This specialized field offers lucrative residential, commercial, and municipal opportunities. Adding leak sealing to your repertoire allows you to tap into a growing market and significantly boost your business. Let's explore how you can leverage your existing skills and experience to excel in this high-demand niche.

Become a Leak Seal Contractor and Tap Into an Expanding Market

The demand for leak seal contractors is on the rise. The need for waterproofing solutions grows as homeowners increasingly convert basements into living spaces. Moreover, aging infrastructure in commercial and municipal settings presents ongoing challenges that require expert intervention. The opportunities are vast and diverse, from parking garages to water treatment systems.

Residential Leak Sealing

Homeowners are becoming more aware of the health risks associated with damp basements. As a result, they're seeking professional solutions to address foundation cracks and floor-wall joint issues. By focusing on this sector, you can build a steady stream of residential clients. You'll also provide a valuable service that improves living conditions and property values.

Commercial and Industrial Applications

The commercial sector offers even more extensive opportunities. Large office buildings, retail spaces, and parking structures all require regular maintenance and waterproofing. Elevator pits and electrical utility vaults are particularly vulnerable to water ingress, creating a constant demand for skilled professionals. By mastering these applications, you can position yourself as an indispensable service provider in the commercial realm.

Municipal Projects

Perhaps the most significant opportunity lies in municipal projects. Aging sewer and stormwater systems across the country are plagued by infiltration and inflow issues. These problems lead to leaking sewer systems, settling roadways, and increased water treatment costs. The demand for leak seal contractors in this sector far outweighs the current supply. You can secure a steady flow of high-value projects by entering this market.

Seize the Opportunity to Become a Leak Seal Contractor

You'll need the right tools, knowledge, and support to become a successful leak seal contractor. Alchatek offers a comprehensive package to help you succeed. High-quality polymers and reliable equipment ensure efficient and effective repairs. Moreover, Alchatek provides expert technical and marketing support to help you overcome common challenges. With Alchatek's assistance, you can deliver consistent results and grow your leak seal business.

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