Filling voids is one of the most common applications for polyurethane concrete repair foam. Geotech contractors use specialized foam to fill voids in the soil under slabs, behind retaining walls, and around municipal infrastructure. In this post, we'll review some of the most popular Alchemy-Spetec blog articles on the subject.

Filling Voids Under Concrete Slabs

In his blog post Filling Dangerous Voids Under Slabs, Alchemy-Spetec's Geotech Division Manager Andy Powell covers the following key points:

• The dangers of soil voids under slabs.
• Signs of a possible void under a slab.
• How polyurethane is used to repair voids.

Click here to read more...

Filling Voids Surrounding a Structure

In his blog post Filling Voids with One-Component Polyurethane, Alchemy-Spetec's Geotech Director of Technical Services Colt Hullander discusses the materials used for this specific application...

Alchemy-Spetec's AP Fill 700 and AP Fill 720 are one-component polyurethanes used for filling voids in supporting soil surrounding a structure. Situations in which these materials might be used for void fill include soil adjacent to retaining walls, basement walls, seawalls, and infrastructure boxes.

Click here to read more...

Filling Voids in a Municipal Leak Seal Context

In his blog post, Sealing Leaks & Voids in Concrete Infrastructure, Alchemy-Spetec's Leak Seal Director of Technical Services Charlie Lerman outlines the causes of and remedies for leaks and voids in concrete infrastructure...

Causes of Leaks and Voids:

• Imperfect construction.
• Weather and wear.
• Unstable soil.

How Injection Grout Helps:

• Water activation.
• Pressure injection.
• Flexible, watertight seal.

Click here to read more...

Want more information on Alchemy-Spetec products?

A large Mid-Western aluminum manufacturer was losing water from all of its quenching tanks. Losing 3 million gallons in half a year can be expensive, not to mention the massive effect that volume of water can have on soil and the structures it supports. So, they reached out to one of their trusted maintenance contractors, who in turn came to Alchemy-Spetec for guidance on how to efficiently mitigate the leaks with minimal downtime. 

Powerful Polymer

After consulting with Alchemy-Spetec, the contractor injected Spetec PUR F400 to seal the leaking cracks. This material is a solvent and phthalate-free, water-reactive, hydrophobic, closed-cell, low viscosity, shrink-free, flexible, one-component polyurethane injection resin designed to shut off water leaks.

Painless Procedure

Concrete crack injection with polyurethane resin is a five-step process:
1. Drill the injection holes.
2. Flush debris out of the holes with water.
3. Install the injection port.
4. Flush the crack with water.
5. Inject the resin.

Rapid Results

The crew repaired leaks in one tank at a time with no manufacturing delays. This meant no production interruption. The work was done at a fraction of the cost of replacing the tanks.

Want more information on leak seal products and equipment?

Enjoy the Advantages and Avoid the Pitfalls

In his blog post, Starting a Slab Lifting Business, Alchemy-Spetec's Geotech Division Manager Andy Powell outlines the advantages and pitfalls of pursuing this line of work...

You can make a lot of money in the slab lifting business. There are many markets to take advantage of, including residential, commercial-industrial, and transportation.

But it would be irresponsible to paint a completely rosy picture of the business and neglect to warn you of the pitfalls. Risk is an underlying factor in any new endeavor, and slab lifting is no different. Threats of failure can arise from problems with your equipment, your lifting material, and your technical knowledge.

Click here to read more...

Enter the Market with a Competitive Edge

In the blog post, Develop Your Competitive Edge, we describe in detail the following advantages that Alchemy-Spetec provides to you...

• Thorough Training & Education Resources
• The Industry's Best Technical Support
• The Industry's Best Marketing Support
• Quality and Selection of Lifting Materials
• Wide Variety of Reliable Equipment & Accessories

Click here to read more...

Call 404-618-0438 today to talk to a specialist about starting up your slab lifting business.

Want more information on Geotech products and equipment?

We've created a video for a question we get asked a lot: "How do I make single-component samples?" A lot of people want samples, sales teams love samples, homeowners love them because it’s actually something they can put in their hands on. They can really help close a deal.

The two samples we're going to be making in this video are:

• An AP Fill 700 permeated sand sample. You'll see the permeated sand at the bottom with the foam on top. People like these because they have a nice smooth finish on them, and they demonstrate both the permeation and foaming aspects of the material. They also demonstrate the strength of the material.
• An AP Fill 720 foam sample. These are great for seawall guys, the infrastructure guys, whenever you want to show an HOA or a marina what the pure foam will actually look and feel like.

Watch the demo video now...

Want more information on geotech products?

Like with most issues, there is no one final answer, but let’s weigh the pros and cons. An easy one is cost: two-component urethanes are significantly more cost-effective than a single component IF you already have a rig to properly handle them. Keep in mind, not many leak seal contractors typically have a rig.

Speed: let’s talk reaction time. While the single component products can have their set time field adjusted, two-component products will almost always react faster. This is helpful when you have gushing leaks, but often you want to give your grout a longer time to migrate and permeate before they react to ensure you get the whole leak. Remember, 99% waterproofed is 100% leaking.

Both types of grouts are isocyanate-based and are closed celled. They both are highly resistant to chemicals, and neither are UV stable. The two-component grouts are always hydrophobic whereas the single component can be either hydrophobic or hydrophilic. In general, most two-component urethane grouts are rigid or semi-rigid. On the other end of the spectrum, single component polyurethanes can be a gel, a flexible foam, a semi-rigid foam, or even a rigid foam.

So, with all that said, single component foams are the traditional choice for leak seal. When it comes to crack and joint water mitigation, flexibility is key and that rules out most of the two-component foams. When we look at curtain grouting, both can be very effective and there can be a substantial cost saving when it comes to two components. But a downside of using two-component is the shorter set time and thus less travel.

In summation, for leak seal, single component grouts can do everything that is needed and are the typical grout of choice.

Want more information on polyurethane leak seal products?

Alchemy-Spetec's Spring 2022 training event is officially SOLD OUT!  If you're still interested in training, we'll be conducting another event in the Fall of 2022.  Click the button below and fill out the form.  We'll keep you updated on the next event and all other training opportunities!

Alchemy-Spetec two-day geotech training events typically consist of the following...

• Geotech Product Line Overview
• Geotech Applications & Case Studies
• PolyBadger® Demo & Training
• Estimating & Quoting Jobs
• PMC Pump Demo & Training
• Leak Seal Issues on Geotech Jobs
• Ground Penetrating Radar Demo & Training
• Slab Lift Rig Demo & Training
• Competing Geotech Techniques
• PolyShark® / Soil Stabilization Demo & Training (On-Site)
• Deep Lift® Demo & Training (On-Site)

Want to be alerted when Fall 2022 training registration is available?

Andrew has over 10 years of experience in Manufacturing Operations and Quality Assurance. With a Six Sigma Black Belt certification, he has a successful track record of evaluating complex manufacturing operations, identifying inefficiencies, and implementing process improvements.

Before joining Alchemy-Spetec, Andrew was Operations Manager at Beaver Paper Group, Production Supervisor at WinCup, and Production Manager at Pursuant Health. Additional skills include Lean Management, Lean Manufacturing, and Kaizen.

Andrew attended Georgia State University and lives in Lawrenceville, Georgia with his wife and son.

Want more information on Alchemy-Spetec products?

Alchemy-Spetec is pleased to welcome Jacob Bryant to our technical support team. Jacob joins the company as Geotech Services Technician. He'll be working with Cult Hullander (Director of Technical Services - Geotech).

Jacob has worked in various forms of construction for the last 8 years. He spent several years working as a technician applying chemical grouts, servicing and maintaining equipment, training new hires, and managing rigs/warehouse stock. He has worked across the United States with a wide variety of polymers and soil types.

Before entering the geotech industry, Jacob worked in roofing, managing crews, installing product, and making repairs. Effective communication was essential in this position. He has extensive experience working with customers and addressing their needs throughout his career.

Want more information on Alchemy-Spetec products?

Newcomers to urethane grouts often cut their teeth on these two terms, but the industry in general struggles with the understanding of what they are, and when to use hydrophobic vs. hydrophilic polyurethane grouts. So, I will cover the differences and then point out what I feel is a much more important conversation about polyurethane chemical grouts.

Hydrophobic

• Cured States: Rigid, Semi-Rigid, Flexible Foam
• Reaction: Requires Water
• Requires Accelerator: Yes
• Elongation: None to 100%
• Wet/Dry Cycling: Unaffected
• Adhesive Bond: Good
• Pumped and Handles as: Single Component

Hydrophilic

• Cured States: Flexible Foam or Gel
• Reaction: Requires Water
• Requires Accelerator: No
• Elongation: None to 300%
• Wet/Dry Cycling: Can Dry Out
• Adhesive Bond: Superior
• Pumped and Handles as: Single Component

Somehow, the industry has erroneously assumed hydrophobic means: "fears water and pushes it away". While at the same time assuming hydrophilic means: "loves water and draws it in". There are some truths in these statements but they are only the core and are wrapped in misconceptions.

Misconception One: Water Loving and Water Fearing

Both grouts require water to activate and yes, the hydrophilic grout can incorporate more of the water into its cell structure, but both grouts will push water away when they have reacted with enough water to polymerize.

Misconception Two: Hydrophilic Grouts Dry Out and Shrink Without Water

A more accurate statement would be that cured hydrophilic urethane grouts can dry out and shrink in an arid environment. Concrete normally has a relative humidity of around 60% which will keep a hydrophilic foam hydrated. Soils can vary in their relative humidity but most often have enough moisture not only to keep a hydrophilic grout hydrated but also enough to polymerize a hydrophobic grout without the need for added water.

Misconception Three: Hydrophilic Grouts Have Better Adhesion

It is 100% true hydrophilic grouts have better adhesion in ASTM lab testing, and I did just list them as having superior adhesion. But, in my twenty-plus years in construction, I have never seen a grout job performed under laboratory conditions. Adhesion requires a clean surface for bonding. During crack injection, surface prep is a water flush in a crack we cannot see. So clearly it would be silly to believe we have a pristine surface inside the crack to adhere to. So yes, in a lab, hydrophilic grouts adhere to concrete better than hydrophobic grouts. In situ, both have a weak adhesive bond and both rely on their compressive and mechanical bonds much more than on an adhesive bond.

So, it's important to understand there is much more to grout selection than just hydrophilic and hydrophobic. I would estimate around 60% of chemical grouters only chemical grout a few times year. This can make product and methodology selection very difficult. That is why I am here with the Alchemy-Spetec team to help navigate you through these critical nuances. Call us at 404-618-0438 for technical assistance!

Want more information about leak seal products?

A retaining wall at a Georgia-based luxury residence was failing due to the pressure of the surrounding soil. A general contractor excavated the site around the wall and planned to install lightweight foam blocks as a replacement for the heavy soil that was removed. After doing a little more research, the contractor discovered that, due to the cost of shipping the blocks, liquid polyurethane foam installation by a local specialized contractor was a lot less expensive. Liquid polyurethane foam takes the shape of the void before curing to form a high-strength solid mass.

Powerful Polymer

The contactor used AP Fill 420 to fill the void. AP Fill 420 is a two-component, high expansion, hydro-insensitive polyurethane foam. It’s the top slab solution for polyurethane void fill. AP Fill 420 weighs 1.8 to 2.2 pounds per cubic foot.

Painless Procedure

The contractor filled the entire void with AP Fill 420 foam. This material was faster to install, less expensive, and provided a more waterproof solution than the foam blocks.

Rapid Result

The entire void was filled with lightweight and extremely durable polyurethane foam. This material placed minimal pressure on the retaining wall, eliminating the danger of future damage. The property owner was extremely pleased with the results.

Want more information on geotech products?