Soil Grouting - Polyurethane vs. Water

GCS on Feb 1, 2019 4:01:52 PM

Soil Grouting - Polyurethane vs. Water

blog-14Not all two-component polyurethane lifting and stabilizing foams are specifically designed for wet environments.  In most situations when a contractor is injecting polyurethane foam into the ground underneath your structure, there is a high probability that the soil is going to be wet.  You need to be confident that the foam will react and retain the desired properties in these wet environments.  If the foam your contractor is using is not specifically designed for wet environments, then you may be getting cheated out of the best possible results.

All polyurethane foams are going to undergo a density change when introduced to water.  This is precisely because the isocyanate (A component) in polyurethane reacts faster with water than it reacts with the polyol (B component).  Some will undergo drastic changes and some minor changes.  It is important to feel confident that the foam your contractor is using will only undergo minor changes.  The density of the foam is very important because density correlates to foam strength, and you are relying on that strength to support your valuable structure.

All the Alchemy-Spetec lifting products we use are formulated to achieve minimum density changes when introduced to wet soil.

Want in-depth info on GCS services?

Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting, Soil Stabilization

Slab Jacking with Polyurethane Foam - Overview

GCS on Jan 31, 2019 8:54:59 AM

Slab Jacking with Polyurethane Foam - Overview

blog-13In countless regions around the world, many structures we build start settling or sinking sooner or later. Sometimes they sink very gradually with the evidence and damage showing up after a long period of time. In other cases, entire homes and roadway sections are swallowed up in minutes. These situations create serious problems for property owners and property managers.

Concrete Lifting is Often the Solution

Certainly, if your house or building has disappeared into a sinkhole, you will need a lot more than slab jacking. But if the issue is uneven concrete slabs, settling foundations, roadways, railways, or sidewalks, then these solutions may be for you. 

Raising Concrete: Technology + Experience = Knowledge to Share

Ground Consolidation Services uses high strength polyurethane lifting foams for slab jacking and structure lifting. In addition to that, our staff has extensive experience fixing problems just like the one on your property. For immediate assistance, call us at 678-337-8374.

Want in-depth info on slab lifting procedures and products?

 Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

Slab Jacking vs. Replacing Concrete

GCS on Jan 28, 2019 3:29:41 PM

Slab Jacking vs. Replacing Concrete

So, you have a sunken concrete slab that could be repaired via replacement or lifting. How do you know which option to choose? Here are a few things to think about.

Slab Jacking vs. Replacing ConcreteRaising Concrete is More Cost Efficient Than Replacing

If the slab is in good shape, and is of a reasonable enough size and thickness, it is usually going to be more cost effective to lift it back into place with structural polyurethane foam. The PMC pumps we use can deliver the AP Lift series of foams we use as far as 400 feet away through heated hoses. And remember, whenever you have new concrete installed, you have to haul away old concrete.

More Environmentally Friendly with Polyurethane Concrete Lifting

Everybody wants to be green and take care of the environment these days, because it's the right thing to do. There is an environmental impact every time concrete is replaced. The cement manufacturing process is the second largest cause of greenhouse gas emissions in the world. Additionally, there is the issue of what happens to old concrete once it is removed. One would like to think it is recycled, but more often than not it ends up being dumped. Hopefully that would be in a landfill, but we've all seen piles of concrete rubble in places where it would be considered trash or pollution. It's worth considering. Meanwhile the AP Lift 430 and AP Lift 475 foams we use are so environmentally friendly they are NSF approved for contact with drinking water in their cured state.

Polyurethane Slab Jacking Requires Less Downtime

How long can you, as a property owner or manager, afford to have that area out of service? Consider a busy warehouse, an airport taxi way, or a bridge approach on a highway. There is an economic impact when those locations are out of service for replacement. It can be a couple days before new concrete is traffic ready. Wouldn't it be better to have it lifted in a few hours, and then back in service 15 minutes after the slab jacking is done?

Want in-depth info on slab lifting procedures and products?

Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

Why Is Your Concrete Slab Sinking?

GCS on Jan 25, 2019 10:00:00 AM
Though there are many reasons for sunken slabs, we have identified the three main conditions that cause the settling issues we like to fix. These include erosion, poor compaction, and biological decay.
 
Though there are many reasons for sunken slabs, we have identified the three main conditions that cause the settling issues we like to fix. These include erosion, poor compaction, and biological decay.
 

Erosion Often Leads to Concrete Slab Settlement


Erosion is the most common cause of settling and the most common reason for slab jacking. Poor drainage, improperly placed downspouts, leaking drain pipes, and broken water lines are common culprits. Water can either slowly erode soil over time, or very quickly erode away the soil beneath a concrete slab or structure causing it to settle.
 

Poor Compaction Can Cause Settlement & the Need for Raising Concrete


Though there are many reasons for sunken slabs, we have identified the three main conditions that cause the settling issues we like to fix. These include erosion, poor compaction, and biological decay.When backfilling on a new construction site, the builder is supposed to walk in backfill (drive over it with heavy equipment) and compact it in small lifts. However, this isn’t always done properly for one reason or another (inexperienced operators or people taking shortcuts). The result can be soil that will continue to compact itself and settle over time.
 
A great example of this is bridge approach slabs. These slabs are found on roads and highways all over the world. Bridges typically sit at a higher elevation than the roads that approach them. During construction, the final section of road (typically a concrete slab) is built on backfill to raise the elevation to meet the bridge. Over time, the slabs can settle due to poor or improper compaction. Compounding the problem is the fact that when a slab settles a little, the expansion joint opens up and allows water to get underneath the road, adding erosion to your compaction problem.
 

Biological Decay Can Result in Sinkholes and Sunken Concrete Slabs


Construction trash pits, buried trees, and other biodegradable materials all eventually break down. Sure enough, there always seems to be some corner of a building or a separate parking area or driveway that ends up right over it. These situations can range from slight settling to very severe.
Sometimes you have a combination of factors that cause settling. As we discussed in the bridge approach slab issue, poor compaction can lead to settling which will open a joint and allow water to compound the problem with erosion. Property owners and managers should not ignore these problems, or they will become more expensive to fix over time.
 

Want more information on GCS services?

 
Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

How We Evaluate Your Site for a Slab Jacking Job

GCS on Jan 23, 2019 10:00:00 AM
Any successful slab lifting job begins with a thorough site evaluation. A site evaluation is not limited to, but should include Identifying the Cause of Slab Settlement, Gathering Information, Identifying Potential Hazards, and Visualizing the Mobilization.
 
Any successful slab lifting job begins with a thorough site evaluation. A site evaluation is not limited to, but should include Identifying the Cause of Slab Settlement, Gathering Information, Identifying Potential Hazards, and Visualizing the Mobilization.
 

Cause of Slab Settlement

Determining the cause of settlement is usually the first step in beginning our evaluation. The cause can be any number of things such as erosion, ground water, sink holes, poor compaction, and buried debris that breaks down over time. Correctly identifying the cause will help us determine if slab jacking alone will solve the problem or whether a combination of lifting, stabilizing, and / or void filling will provide the permanent solution.
 

Gathering Information

Any successful slab lifting job begins with a thorough site evaluation. A site evaluation is not limited to, but should include Identifying the Cause of Slab Settlement, Gathering Information, Identifying Potential Hazards, and Visualizing the Mobilization.The next phase should include gathering information from multiple sources. This includes dimensional information such as length and width of the slab; but also, the amount it has dropped, to help determine the volume of structural foam needed to lift the slab back into place. We also gather information from the property owner; finding out about any known irrigation, electrical, water, or drain lines. Specifically, we find out from the owner about any areas or features that need protecting around the injection site, the location of our rig, and all points in between where our crew may be working.
 

Identifying Potential Hazards

If the job is outside of a building, we find out where the utilities are and have them professionally located. Additional information that may be available could include a soil engineering report, a structural engineering report, and reports from the builder of the structure. We also consider other issues that might create problems like slabs binding (concrete saw?), bent rebar from a settled slab, etc. 
 

Visualizing the Mobilization

After the data gathering is complete, we visualize the job site as a whole and consider any challenges to mobilizing and physically reaching the areas that need lifting. We consider the size of the rig we're using on the job compared to the site size, the amount of pump hose we'll need to reach the lifting points, the power we'll need, etc. 
 
Some of the above seem obvious, but it's often the obvious things that get overlooked by the common contractors out there. Mistakes can drastically affect the cost to the property owner, in terms of both time and money. There's a reason why highly skilled airplane pilots go through the same checklist prior to every flight. Sometimes you only get one chance to choose the right contractor.
 

Want more information on GCS services?

 
Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

Deep Lift Services Available in Atlanta Area

GCS on Jan 21, 2019 10:00:00 AM

The Deep Lift™ process is different from common slab lifting in that it requires polyurethane foam to be injected deep into the soil beneath the structure. It is often appropriate for larger structures and more flexible pavements that may not be ideal candidates for conventional slab lifting.

The Deep Lift™ process is different from common slab lifting in that it requires polyurethane foam to be injected deep into the soil beneath the structure. Deep Lift™ is often appropriate for certain larger structures and more flexible pavements that may not be ideal candidates for conventional slab lifting. It can also be used in conjunction with conventional slab lifting. In this post, I'll provide a quick overview of the Deep Lift™ process and its many applications.

The Process:

The Deep Lift™ process is different from common slab lifting in that it requires polyurethane foam to be injected deep into the soil beneath the structure. It is often appropriate for larger structures and more flexible pavements that may not be ideal candidates for conventional slab lifting. Complete a thorough site evaluation including – soil borings, DCP testing, and Deep Look ground penetrating radar as necessary

  1. Address any potential binding with saw cutting, clearing of joints, and removal of old grout
  2. Based upon soils data, calculate grid spacing and injection depths
  3. Drive injection tubes to the correct depths and locations
  4. Inject high strength deep lifting foam in the predetermined sequence while monitoring for lift
  5. Follow the grout plan, adjusting the injection depths and locations as the structure raises into place

The Applications:

  • Bridge abutments
  • Highway approach slabs
  • Rigid and flexible pavements
  • Ports and airports
  • Settled buildings
  • Soil densification and encapsulation
  • Lift stations
  • Pipe and tunnel segments
  • Equipment pads

Want more info on GCS services?

Download an Info-Packed GCS Services Brochure NOW!

Topics: Deep Lift, All Posts

Polyurethane vs. Cement for Slab Jacking

GCS on Jan 18, 2019 10:23:11 AM

We are often asked about the biggest advantages of lifting settled concrete slabs with polyurethane foam vs. cement grout.  In this blog post, we spell it out...

Polyurethane vs. Cement for Slab Jacking-blogSlab Jacking with Lighter Material Prevents Further Sinking

We are often asked about the biggest advantages of lifting settled concrete slabs with polyurethane foam vs. cement grout.

One of the biggest advantages is the weight.  Depending on the product, the density of structural polyurethane lifting foam is between 3 ½ and 5 pounds per cubic foot.  The same volume of cement grout weighs 140 pounds per cubic foot. This translates to 30 to 40 times more added weight using cement vs. polyurethane. By hiring an expert contractor who uses these lighter weight materials, you are giving yourself a much greater chance for long term success.  (Polyurethane is strong enough to support any structure, as explained in our earlier blog post How Strong is Strong Enough.)

Concrete Lifting with Polyurethane Creates Less Mess

Another advantage of using foam is the small size of the drill holes.  Drilling holes for foam is quick and easy, requiring only a 3/8” hole to inject through.  For mud jacking the contractor is drilling injection holes into your slab that range from one to two and a half inches.  This takes longer and does more damage to your concrete.  Also, mud jacking brings the additional problems of messier works sites and disposal of unused mixed cement.

Mudjacking with Cement Requires Longer Cure Times

The final advantage of foam over cement is time.  All of the AP Lift series foams we use reach 90 percent of their final strength in 15 minutes and are fully cured in less than a day.  Literally, as soon as we are done packing up our equipment the foam under your slab is ready for traffic.  On the other hand, cement grout can take days to reach final cure.  (Having immediate load bearing traffic is especially important if you own or manage facilities such as warehouses that run 24/7 and need to use the lifted area as soon as the job is complete.)

Want in-depth info on slab lifting procedures and products?

 Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

Concrete Slab Jacking With Polyurethane Foam – How Strong is Strong Enough?

GCS on Jan 16, 2019 5:38:53 PM

When pumping a light-weight material beneath a slab, you need the confidence that it is strong enough for the application. How strong is strong enough?

Concrete Slab Jacking With Polyurethane Foam – How Strong is Strong Enough_-blogRaising Concrete with Confidence

When light-weight material is being installed beneath your slab, you need the confidence that it is strong enough for the application. How strong is strong enough? This is a commonly asked question by property owners or managers that are new to slab jacking with polyurethane. The structural foams we use only need to be as strong as dirt, but they're actually stronger than crystalline bedrock.

The Right Strengths for Concrete Lifting

Slab lifting foams are rated on density (weight per cubic feet) and compressive strength. This testing and rating is based on the foam in a free rise state; the parts A and B are mixed together and allowed to expand freely.  The foams we use the most, AP Lift 430 and AP Lift 475, for example, will weigh 2.75 – 3.25 lbs (AP Lift 430) to 4.75 – 5 lbs (AP Lift 475) per cubic foot. But they have a compressive strengths of 50 psi and 100 psi in a free rise state. That's equal to 7,200 to14,000 lbs per square ft of support, just in a free rise state.

Polyurethane Slab Jacking Compared to Clay and Bedrock

To put that into perspective, the National Home Builders Association and the International Building Code lists stiff clay at 4000 psf and crystalline bedrock as having 12000 psf of load bearing capacity. Consider the job site conditions where the foam will be injected into a confined area. Testing data in the lab shows that our lifting foams will increase in compressive strength: In a space confined 25% by volume there will be an increase of 31% in psi and in a space confined by 75% there will be a 79% increase in the psi.

Slab Jack for Any Job with the Right Foam

Today polyurethane lifting foams are used to level airport slabs supporting jumbo jets, equipment and building slabs supporting tremendous loads, and even railway sleepers that support the heaviest freight trains. So don't let the word “foam” fool you. These resins cure to strengths beyond what is needed to support any structure.

Want more in-depth info GCS slab lifting services?

 Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Slab Lifting

Polyurethane Soil Stabilization Explained

GCS on Jan 14, 2019 5:14:19 PM

Unstable, eroded, or loose soil can result in settlement and damage. Soil can be stabilized with polyurethane. Watch this animation for a detailed explanation of the process in a variety of settings!

Unstable soil can be defined as soil that will not stay in place on its own, and therefore requires extra support. It should be noted that unstable soil can threaten the stability, security, and safety of infrastructure and can damage, degrade, and even destroy a number of structures, such as buildings, bridges, and roads. There are a variety of factors that can cause unstable soil including erosion, poor compaction, freeze/thaw cycles and decomposition.

Soil can be stabilized with high strength polyurethane foam. Once the bearing capacity of the soil has been increased with this process, then the structure can be lifted if necessary.

For a detailed explanation of the process in a variety of settings, watch this animation from our materials supplier Alchemy-Spetec... 


Want more information on GCS services?

Download an Info-Packed GCS Services Brochure NOW! 

Topics: All Posts, Soil Stabilization

The Deep Lift Process Explained

GCS on Jan 11, 2019 5:23:36 PM

GCS offers a unique combination of high-quality structural lifting foams along with the equipment and training needed to address deep soil issues. Now you can achieve soil densification and lifting on large projects with the smallest footprint and least amount of equipment required.

Poor compaction, water erosion, broken pipes, and organic material in the soil can all lead to settling of a foundation or a roadway.  Traditional slab lifting can bring concrete and structures back into place, but it doesn’t necessarily address the underlying issue or guarantee a long term fix.  Other methods of addressing deep soil issues require heavy equipment, extended down-time, and collateral property damage.  These situations create problems for property owners as well as opportunities for the elite contractors that know how to fix them.

GCS employs a unique combination of high-quality structural lifting foams along with the equipment and training needed to address your deep soil issues. Now you can achieve soil densification and lifting on large properties with the smallest footprint and least amount of heavy equipment required.  The Deep Lift™ process is powerful, painless, and rapid. Deep Lift™ gets to the root of the problems in the soil, it brings the structure back to level, and accomplishes this with minimal imposition or downtime to the property owner.

For a detailed explanation of the process, watch the animated video (from our materials supplier Alchemy-Spetec) below...  


Want more information on GCS services?

Download an Info-Packed GCS Services Brochure NOW!

Topics: All Posts, Deep Lift