Alchatek Blog

Manhole infiltration can pose serious risks to nearby structures. In a recent case, water infiltration pulled soil into a manhole, eroded the ground beneath a walkway in front of a residence, and threatened to compromise the home's foundation. Specialists from SiteMix Pressure Grouting, LLC were called in to perform repairs to address this urgent situation.

Powerful Polymers

Two key products were selected for the job. First, AP Fill 700 was chosen to stabilize the soil around the manhole and seal the leaks. This product features low viscosity, making it ideal for permeating soil and sealing thin cracks. Additionally, it activates with moisture, which is perfect for damp environments like this one. Secondly, AP Lift 430 was selected to stabilize the house's footing. This high-density product cures quickly. Furthermore, it excels at filling voids and stabilizing soil near structures due to its high load-bearing capacity.

Painless Procedures

The repair process began with stabilizing the soil around the manhole. To achieve this, injection rods were driven into the ground around the structure. Then, AP Fill 700 was injected to seal the leaks and stabilize the surrounding soil. Next, the team focused on the large void areas around the house's footing. Once again, injection rods were utilized. This time, AP Lift 430 was injected to fill the voids and secure the foundation.

Rapid Results

The repair project yielded impressive outcomes. First and foremost, the manhole was successfully sealed. In addition, the surrounding soil was stabilized, preventing further erosion. The walkway, previously at risk, was now secure. Importantly, the voids adjacent to the house were filled, protecting the foundation. Remarkably, all these tasks were completed in less than a day. Finally, the repaired area was prepared for the county to add backfill around the newly stabilized manhole. This swift and effective solution ensured the safety of both the property and its residents.

Want more information on stabilizing soil with polyurethane?

The Army Corp of Engineers (ACOE) builds and manages numerous projects along the rivers and waterways of the United States. On our mightiest river, the Mississippi, the ACOE was tasked with upgrading the large siphon systems that are used to draw down the river level during flood events. To prevent catastrophic flood damage, these siphons kick on if the river is going to crest over the top of the levees.

The first thing you see when you visit the site is a massive concrete bulkhead about 30 feet tall, 8 feet thick, and over 100 feet wide. Penetrating through the bulkhead are eight 84” ductile iron pipes through which the river water is ejected if the siphon kicks on. It is at these penetrations that the ACOE was looking for some ideas.

When the bulkhead was constructed, eight large square holes were formed across the face before pouring the concrete. It is through these large square holes that the 84” diameter pipes are placed. The ACOE was looking for solutions to fill the annular space between the round pipe and the square hole.

Powerful Polymers

After consulting with New Orleans-based contractor KMH Coatings and the ACOE, it was decided that a high-density polyurethane foam would be perfect for the application. NSF-approved AP Lift 430 was selected as the go-to product. Its combination of excellent strength, yield, and bond is ideal for these kinds of structural void fill applications, but most importantly it is watertight.

Painless Procedures

KMH mobilized their polyurethane spray rig and the AP Lift 430 was sprayed into the annular space around each of the 8 pipes. AP Lift 430 is most commonly known as a first-class concrete lifting polymer but a large percentage of applications are void fills. Once the void was filled, they attempted to cut off the overspray but it proved to be too dense to cut. Instead, a disc grinder was used to sand down the polymer foam flush with the face of the concrete bulkhead.

Rapid Result

The ACOE was extremely impressed by the toughness of the product and with the minimal time that it took to install it; two days from start to finish. 

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In Cape Canaveral, Florida, a heavily loaded slap stand structure was planned for construction along a transfer aisle in the Vehicle Assembly Building (VAB). This slap stand would be critical in servicing the proposed Space Launch System vehicle (SLS). However, the project faced a significant challenge when it was discovered that the near-surface subsoils consisted of loose fill materials susceptible to further densification and volume loss due to vibrations and water infiltration. With the slap stand tentatively designed to bear directly upon the ground-level floor slab of the VAB, the degree of subsoil support beneath the floor slab section became a critical concern.

Powerful Polymers

To address this issue, the geotechnical engineer of record recommended a ground improvement solution using permeation grout. Helicon, a leading soil stabilization contractor, worked alongside the geotechnical design team to develop a permeation grout program that would meet the building code load criteria. AP Soil 600, a high-strength, hydro-insensitive structural polyurethane foam, was selected as the ideal product for this project due to its exceptional ability to support heavy structures.

Painless Procedure

Helicon’s technicians installed permeation grout injection pipes on a center-to-center spacing of approximately 2 feet across each of the slap stand areas. The injection points were driven to a depth of at least 5 feet below the floor slab grade. Grout was injected at a relatively low pressure (less than 50 psi), and grout needles were slowly withdrawn during pumping to ensure a uniform distribution of grout to about 3 feet below the bottom of the slab level. The amount of grout used was carefully controlled, with less than 15 gallons per foot per injection point.

Rapid Result

The permeation grout project was a resounding success, effectively improving the load-bearing capacity of the existing soils at the site. The precise application of AP Soil 600 ensured that the slap stand structure would have a stable and reliable foundation, allowing for the safe and efficient servicing of the Space Launch System vehicle. Thanks to Helicon’s expertise and the power AP Soil 600, this piece of critical infrastructure in Cape Canaveral was reinforced and readied for countless future space exploration missions.

Want more information on stabilizing soil with polyurethane?

Polyurethane foam can be used in a variety of new construction projects, from road widening to zero lot line excavation projects to a variety of complex excavation and foundation support scenarios. The use of polyurethane stabilization techniques provides clear advantages like cost-effectiveness, strength, and versatility across a wide range of situations. However, properly implementing them requires extensive technical expertise in assessing site conditions, selecting the right materials, and creating effective injection plans.

Technical Guidance and Contractor Referrals

Before hiring a contractor to do any polyurethane injection work, consultation with industry specialists is highly recommended. With decades of experience in chemical grouting, the Alchatek support team possesses in-depth knowledge for assessing site conditions and challenges. 

In addition, Alchatek maintains strong relationships with experienced polyurethane foam application contractors. Referrals are available to reputable construction experts who can safely and effectively execute projects.

A Partner for Success

Don't leave the success of your new construction endeavor to chance. Connect with the specialists at Alchatek to leverage the full benefits of polyurethane foam for upcoming projects. Reach out today!

Call 404-618-0438 or fill out this form to contact Alchatek today!

Want more information on soil stabilization with polyurethane?

In new construction projects, establishing a solid foundation for footings and slabs is crucial, especially in challenging soil conditions. Polyurethane foam offers a groundbreaking approach to improving soil stability, a key factor in the longevity and safety of new structures.

Cost-Effective and Durable

In new construction, utilizing polyurethane foam for soil stabilization beneath new footings and slabs presents a more economical and efficient approach compared to the conventional practice of excavating and replacing unstable soil. This method not only reduces costs but also greatly enhances the structural integrity of the foundation.

Effective in Waterlogged Conditions

One of the standout features of polyurethane foam is its efficiency in waterlogged or saturated soil conditions. The foam's ability to displace water ensures a stable base, even in areas with high water tables. This characteristic is particularly beneficial for constructions in challenging terrains, where water presence can complicate traditional building methods.

Supporting New Footings and Slabs with Polyurethane

The application of polyurethane foam underneath new footings and slabs represents a significant advancement in construction technology, offering a more efficient, cost-effective, and reliable method for building stable foundations.

Want more information on soil stabilization with polyurethane?

As construction excavation projects continue to push the boundaries of complexity, innovative solutions are needed to ensure safety and stability. Polyurethane foam has emerged as an indispensable tool for these unique challenges. With a dual capability to stabilize soil and complement traditional retaining methods like sheet piling or secant walls, polyurethane foam provides robust support precisely when and where it is most needed. Whether plugging gaps to prevent infiltration, enhancing structural support, or sealing out soil in deep foundation pits, this versatile material enables advanced excavations that would otherwise be extremely risky if not impossible.

Support for Traditional Excavation Methods

Polyurethane foam serves the important dual role of both stabilizing soil and supporting traditional methods in complex excavation projects. Used alongside methods like sheet piling and secant piling, the foam creates an impermeable curtain wall injection that seals out the soil. This barrier is crucial for maintaining the stability of surrounding structures.

An Indispensable Modern Tool 

The versatile applications of polyurethane foam demonstrate its indispensability in modern construction. Its ability to adapt to challenging excavation scenarios and bolster conventional techniques makes the foam a critical component in ensuring safe and successful projects.

Want more information on soil stabilization with polyurethane?

Excavating near existing structures, particularly in zero lot line scenarios like building additions, poses unique challenges. Traditional methods like sheet piling, while effective, can cause issues such as adjacent structure disruption, soil settlement, and excessive noise, making them less ideal in dense, urban environments.

Polyurethane Grout Walls

The use of polyurethane grout walls, composed of interlocking columns, offers a more suitable solution. This method involves injecting a single component, like AP Soil 600, into non-cohesive soil, creating a stable barrier that supports the excavation site without affecting the adjacent structure.

The Advantages of Polyurethane in Non-Cohesive Soils 

In non-cohesive, loose soils, polyurethane grout walls provide several benefits:

1. Reduced Structural Impact: They minimize the risk of damaging nearby structures.
2. Lower Noise Levels Compared to Sheet Piling: The installation of polyurethane grout walls is significantly quieter than the installation of sheet piles.
3. Soil Stability: Polyurethane enhances soil stability, ensuring safety during and after excavation.

This approach is not suitable for more cohesive soils in which the installation of grout columns is not possible, emphasizing the need for careful soil assessment beforehand. This installation of grout walls to stabilize adjacent structures during excavation is a more precise and less invasive alternative to traditional methods.

Want more information on soil stabilization with polyurethane?

Road widening projects, essential for improving traffic flow and infrastructure, traditionally involve digging up and replacing unstable soil. This method, however, poses risks to existing roads and is both costly and time-consuming. The use of polyurethane foam to stabilize existing soil is often more efficient and effective.

The Use of Polyurethane Foam 

In non-cohesive soils, which are loose and permeable, a single-component material like AP Fill 700 is most effective for ground permeation. For cohesive soils like clay, a dual-component material such as AP Lift 475 is more suitable for ground compaction. These materials are injected in a grid pattern to stabilize the soil beneath the road.

Advantages Over Traditional Methods 

This new approach offers significant benefits:

1. Minimized Risk to Adjacent Structures: Unlike traditional methods, polyurethane foam injection does not destabilize adjacent areas.
2. Cost-Effectiveness: The process reduces both material and labor costs.
3. Time Efficiency: Foam injection is faster, accelerating project completion.

The use of polyurethane foam in road widening not only enhances efficiency but also maintains the integrity of adjacent structures, marking a significant advancement in construction technology.

Want more information on soil stabilization with polyurethane?

For contractors seeking productive work during the slower winter months, Alchatek is here to help every step of the way.

Our team can provide guidance on expanding your services to take on new projects during cold weather. When you’re undertaking new winter work, we're available to consult on important logistics like site evaluations, scheduling, equipment selection, and material adjustments for colder temperatures.

We offer personal consultation to equip you with any new skills required for off-season jobs. We also collaborate with contractors to build relationships with local engineers, associations, municipalities, and other potential lead sources. Our staff can assist with tailored presentations and outreach efforts to position you as the go-to contractor for these clients.

Properly winterizing your slab lifting equipment is equally crucial if you’re winding down for an off-season. Our technical experts can advise you on prepping your slab lifting rig and/or PolyBadger lifting system for winter storage.

Contact the Alchatek support team today to for assistance with your winter game plan.

For in-depth information on geotech polyurethane applications...

This guide outlines a step-by-step process for setting up your PolyBadger system for winter storage. Following these recommendations will not only preserve the integrity of your equipment but also make it easier to get it running when the warm weather returns.

Preparing a PolyBadger for Winter Storage

1. Establish power to the cabinet and heat the hose (A heater, B heater, and hose) to the target temperature of 130° F.
2. Introduce material to the cabinet.
3. Turn the air supply on and recirculate to heat up the ISO and resin.
4. Once the PolyBadger is up to temperature, turn off the air supply and remove the airlines from the stick pumps.
5. Remove the supply and the recirculation line from the A-side stick pump.
6. Drain all the remaining material from the pump and clean it with brake cleaner.
7. Place the stick A side stubby stick pump into a 5-gallon pail of AP Pump Flush.
8. Reconnect the supply line and leave the recirculation line to drain in a purge pail.
9. Repeat steps 5-8 on the B-side stick pump.
10. Reconnect the air supply to the stick pumps, hold the return lines in a purge pail, and slowly open the air valve on the stick pumps.
11. You will notice material slowly pushed out of the recirculation line into the purge pail. Continue to pump AP Pump Flush through the system until it comes out of the recirculation line clear, with no added color or debris.
12. Shut the air valve supplying the stick pumps. This will stop the flow of material.
13. Reconnect the recirculation lines to the appropriate stick pump and tighten.
14. Turn the recirculation pump valves to supply the hose.
15. You can remove the Handi Gun or leave it on for this stage, holding the hose in the purge pail. Turn on the supply valves on the end of the hose just before the Handi Gun. Slowly open the air valve on the stick pumps and pull the trigger on the gun.
16. You will notice material slowly pushed out of the hose line into the purge pail. Continue to pump AP Pump Flush through the system until it comes out of the hose line clear, with no added color or debris.
17. Shut the air valve supplying the stick pumps. This will stop the flow of material.
18. Remove the stick pumps from the AP Pump Flush. (Make sure to mark your pails A and B for future use).
19. Insert stick pumps into AP Pump Saver 195. (Make sure to mark your pails A and B for future use).
20. Push the AP Pump Saver 195 through the hose line. You will notice the AS Pump Flush slowly pushed out of the hose line into the purge pail. Continue to pump AP Pump Saver 195 through the system until it comes out of the hose line clear (you will notice a thick, clean fluid).
21. Turn off the supply valves on the hose just before the Handi Gun.
22. Disconnect the air supply to the stick pumps.
23. Move the hose supply valve into the recirculation position to depressurize the system.
24. Shut off supply valves to the cabinet.
25. Turn off heat zones.
26. Turn off the main disconnect.
27. Remove residual grease from interior cabinet pumps.
28. Replace with new grease.

If you follow these steps, your PolyBadger should be ready for secure storage during the winter months.

For in-depth information on geotech polyurethane applications...