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Concrete Floor Repair Projects

By applying unique solutions to increase the safety and longevity of our environment.

New Jersey polyurethane grouting

The Job

This New Jersey polyurethane grouting project is located in Creskill, New Jersey. As part of a full gut renovation of the library, the architect specified lifting settled areas of the floor. The floor settlement was affecting approximately 3200 square feet, with settlement up to two inches.

The Challenge

The library building is a slab on grade, with relatively light design loads. The floor is approximately four inches thick, and reinforced with welded wire mesh. The original design to correct settlement was to use mud jacking. Mud jacking works well, but is rather slow, and tends to be very messy. Mud jacking uses cement-based grout pumped under high pressure below concrete to fill voids and push the concrete back up. A downside is that the grout is quite heavy, and the additional weight it adds to already compromised soils can cause additional future settlement.

The Solution

CJGeo proposed using CJGrout 28FDL geotechnical polyurethane grout as an alternative to the specified mud jacking process. CJGeo’s value engineer proposal was based on the following benefits of polyurethane grouting over traditional cementitious grouting:

  • speed – polyurethane grouting tends to be significantly faster than cementitious grouting
  • cleanliness – polyurethane grouting is a very clean process, including dustless drilling, mechanical connections to the slab, and material that scrapes off with a putty knife if it leaks from below a slab
  • density – traditional mud jacking grout is approximately 50 times heavier than in place CJGrout 28FDL. This reduces the likelihood of future resettlement by minimizing the additional load that grout places on the underlying soils.

The architect and structural engineer accepted CJGeo’s value engineering proposal for this New Jersey polyurethane grouting repair. A crew of three CJGeo polyurethane grouting experts completed the repair in less than a day. Because polyurethane cures within a few minutes, the general contractor was able to move on to the next steps in the project very quickly.

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Norfolk polyurethane grouting

The Job

This Norfolk polyurethane grouting project is located on a military base. The medical clinic on a military base was being renovated. As part of the renovation, the 650sqft elevated slab front porch needed to be replaced. The slab “sounded hollow,” and the presumption was that there were nominal voids below the slab.

The Challenge

At the start of demolition, the demolition contractor determined that the voids below the slab were closer to 3′ deep. This presented a safety problem for the demolition. The concern was that the slab would fail catastrophically during demolition. The general contractor reached out to CJGeo about ways to reduce the void depth.

The Solution

CJGeo proposed void filling below the slab using CJGrout 20SDB. CJGrout 20SDB is a low exotherm bulk void filling geotechnical polyurethane specifically formulated for deep fill placements without scorching or charring.

CJGrout 20SDB cures to 95% of final strength within a few minutes. Because of this, by the time the crew is packed up to leave the site, the material is effectively completely cured. This is significantly faster than cementitious grouts like flowable fill, and facilitates fast return to service. Because 20SDB is very light, it also reduces the likelihood of inducing settlement compared to traditional flowable fill.

A two person polyurethane grouting crew mobilized to the site and placed approximately 2,900lbs of CJGrout 20SDB in a few hours onsite, allowing the demolition contractor to safely resume work.

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Facing a similar challenge to this Norfolk polyurethane grouting project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Warehouse Floor Joint Stabilization

The Job

This floor joint stabilization project is located in Ashland, Virginia. About two months after occupying a new warehouse, the tenant identified two joints where the floor “popped” at a joint when a forklift drove over them. After consulting the plans, the owner determined that the joint wasn’t doweled, and needed warehouse floor joint stabilization.

The Challenge

Both affected joints were on main, high frequency travel pathways within the warehouse. So, any repairs had to be done quickly, and with zero impact to operations.

The Solution

CJGeo proposed undersealing the two joints, which had experienced slab curl, with high density geotechnical polyurethane grout. In fewer than three hours onsite, CJGeo undersealed the joints with CJGrout 20SDB, load tested them, and demobilized. There were no impacts to operations of the facility during this warehouse floor joint stabilization repair.

Undersealing is the best method for addressing slab curl joint popping. Grinding or polishing, an alternative method does not stop the movement. Filling joints with rigid joint filler can temporarily stop movement, but typically results in fatigue and cracking. Undersealing for slab foundation repair completely fills the voids below the floor so that the floor can’t move. If the curl is significant enough that it affects ride, polishing can be done afterwards to address ridges.

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Facing a similar challenge to this warehouse floor joint stabilization project by CJGeo? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Dollar Store Floor Void Filling

The Job

This floor void filling project is located about three hours west of Richmond, Virginia. A commercial contractor was performing a full gut renovation of a dollar store in a strip center. The building was approximately 30 years ago, and there were no signs of floor slab failure or settlement.

The Challenge

While cutting through the floor to install utilities, a 3″ void was discovered below the floor. Exploratory coring determined that voids ranged from 0.5 to 4″ throughout approximately 11,000 square feet of the space. The front of the building is at grade, but the rear of the building has an approximately 7′ tall CMU stem wall, which was backfilled with common borrow during original construction.

The Solution

The general contractor reached out to the structural engineer to notify them of the problem. The structural engineer then reached out to the geotechnical engineering, who recommended polyurethane grouting as the best way to fill voids below a floor. The geotechnical engineering is familiar with polyurethane grouting from working with CJGeo on similar repairs in the past. They know that polyurethane grouting:

  • is very clean and fast, so is unlikely to slow progress
  • is very lightweight, so is least likely of all grouts to cause additional settlement
  • effectively cures instantly, allowing immediate resumption of activities in the area

CJGeo mobilized two geotechnical polyurethane grouting crews to the site and filled the voids over a period of two days. It took about 7,000 pounds of CJGrout 20SDB through approximately 500, 5/8″ holes to completely fill the voids. Cut-off criteria was cross-hole communication. The work was performed without disruption to the renovation activities.

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Facing a similar challenge to this floor void filling project by CJGeo? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Fire Station Floor Lifting

The Job

This fire station floor lifting project is located about an hour east of Richmond, Virginia. The concrete slab on the grade floor inside of a fire station on the North Neck of Virginia settled up to two inches. As part of the investigation into the cause, an engineer discovered voids up to 8″ below the slab and multiple broken sanitary sewer pipes below the floor.

The affected areas needing slab foundation repair included a dayroom, kitchen & meeting hall.

The Challenge

In order to minimize disruption to the fire station’s operations, the proposed repair had to be quick, clean, and minimize uncertainty associated with the plumbing repair slab cuts.

The Solution

CJGeo performed ground improvement grouting of the underlying soils to 5′ below-grade utilizing plural component polyurethane compaction grouting, with CJGrout 35NHV. During the compaction grouting process (sometimes called structural polymer grouting), the CJGrout 35NHV lifted the floor back into place.

Because polyurethane grouts cure very quickly, the floor was repaired the day before the plumbing work was scheduled. This allowed the plumbers a stable work surface and eliminated the risk of stuck saws or sudden collapse of the floor during floor sawing for plumbing access.

Grouting sufficiency was verified by using pre & post-grouting DCP tests.

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Facing a similar challenge to this fire station floor lifting project by CJGeo? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Corporate HQ Stabilization

The Job

Starting immediately after construction was completed, the slab on the grade floor within the cafeteria, loading dock, and kitchen at a corporate headquarters building in Pittsburgh, Pennsylvania settled. Over the course of 12 years, the owner had four different grouting companies attempt to address the problem. Lime slurry injection below the slab was disruptive, and settlement always resumed shortly thereafter.

Compaction grouting was performed in one area but was so disruptive that despite the fact that it was the only method where settlement didn’t resume, the owner kicked the contractor off the site after nearly four months of not having access to their executive dining room.

The Challenge

Settlement progressed over time to be as much as four inches, affecting nearly 20,000 square feet of floor. A general contractor retained by the owner reached out to CJGeo about performing low-impact grouting to address the settlement.

Because settlement affected the entire kitchen, food prep, serving and majority of the dining areas, repairs had to be facilitated continued use of the facility. Additionally, due to the 24-hour staffing of the facility, the noise had to be limited, and there was zero tolerance for dust.

Video inspection of the extensive gravity sanitary and floor drains below the floor revealed six defects, including a 2″ offset in a sanitary drain line for a 6 stall restroom.

The Solution

CJGeo performed 17 DCP tests to determine the depth of uncontrolled fill, which was the presumed cause of settlement. DCP testing showed pockets of WOH fill down to 35′ below the finish floor, and voids ranging from 2″ to 18″ immediately below the floor.

Over the course of 7 nights onsite, CJGeo crews installed 12,000 pounds of CJGrout 20SDB into voids immediately below the floor, and 53,000 pounds of CJGrout 35NHV61 for polyurethane compaction grouting. Compaction grouting was performed up to 35′ deep, but to an average depth of 15′ over the entire area.

All work was completed off-hours. As soon as the kitchen shut down for the evening, CJGeo crews swung into action, grouting through the night until wrapping up in time for the food prep crews to get ready for breakfast at 0500.

To facilitate grouting under four walk-in freezers and refrigerators, over the course of a 24-hour shift, all cold contents were moved to reefer trailers, CJGeo grouted to 30′ under the freezers and refrigerators, which were then immediately turned back on, and then refilled.

Through careful coordination with multiple operational divisions for the owner, general contractor, flooring restoration contractors, plumbers, and remediation contractors, CJGeo successfully completed the project under budget and on time.

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Sewer Collapse Sinkhole Repair

The Job

This sewer collapse sinkhole repair project is located in central Virginia. When the operators of a tire and auto shop noticed a sinkhole developing next to their building. They weren’t sure what to do. After an employee crawled into the hole and discovered that he could stand up underneath their building, the owner reached out to the city. City crews determined that a 20″ VCP combined sewer & storm pipe had collapsed under the structure, roughly 25′ below grade.

The Challenge

An on-call contractor for the city installed a new manhole and rerouted the pipe around the building. However, addressing the sinkhole was out of their businesses’ scope. The project manager reached out to CJGeo, who visited the site and recommended DCP testing to better quantify the extent of the problem.

The Solution

DCP testing showed that outside of the large hole on the surface, there was little deep disturbance. Working with the city’s consulting engineer, CJGeo developed a grouting plan to install two different CJGrouts. 20SDB in the bulk voids near the surface. And 35NHV61 for soil grouting to address voids within the underlying ground near the failed sewer line.

While onsite for just 6 hours, a CJGeo crew completed the work with zero disruption to the businesses’ operations.

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Facing a similar challenge to this sewer collapse sinkhole repair project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

School Floor Leveling

The Job

This school floor leveling project is located in Princeton, West Virginia. The Princeton Middle School is a slab-on-grade masonry structure and serves approximately 550 students in grades 6 through 8.

The Challenge

The corridor floor in the arts wing settled up to 3.5 inches. A geotechnical investigation found voids up to 2.5 inches below the settled slab. Due to budgetary constraints, the repair needed to address the settlement & instability without requiring flooring replacement.

A hand auger confirmed that the fill material below the slab had consolidated to the point of providing sufficient capacity. So, there was no need for polyurethane compaction grouting, which would have been useful if the soils were still loose.

The Solution

CJGeo mobilized a two-person polyurethane grouting crew to the site. Over a few hours, they filled all the voids utilizing CJGrout geotechnical polyurethanes and corrected the settlement. After the floor was lifted back into position and the voids all filled, the custodian reinstalled the cove base at the correct height. CJGeo patched the injection holes with off-white stained grout to match the VCT flooring.

CJGeo used CJGrout 28FDL for this repair. 28FDL is a fast, dry environment lifting foam that works great for lifting bellies out of lightly loaded slabs. There were no water leaks below the slab, there was a significant belly, and the loads were less than one tenth of the grout’s capacity, so it was a great fit. To make sure there weren’t any remaining voids, the crew installed CJGrout 20SDB, which is higher mobility than 28FDL.

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Facing a similar challenge to this school floor leveling project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Tunnel Abandonment – Boston

THE JOB

A plumbing contractor hand tunneled 140LF of 4’x5′ tunnel under two apartment buildings near Boston, Massachusetts. In preparation for a renovation project, a structural inspection was performed. The structural inspection revealed the slab floors which were tunneled under were not designed as structural slabs. The structural engineer directed the property owner to immediately fill the tunnels to restore structural integrity.

THE CHALLENGE

The tunnel abandonment work had to be completed during the winter, and while one of the two affected buildings was occupied. The non-occupied building was also in the process of asbestos abatement and a full gut renovation.

Due to the plumbing running through the tunnels, an excavatable grout was required. Also, the grout had to be low exotherm in order to not affect the new PVC plumbing.

THE SOLUTION

CJGeo proposed polyurethane grouting for the tunnel abandonment. Polyurethane grouting can be performed in any weather, is low exotherm, and can be placed in very thick lifts. The specific grout chosen was a low exotherm bulk void filling polyurethane.

CJGeo mobilized a polyurethane grouting truck with more than 9000 pounds of polyurethane grout, due to the unknown exact volume of the tunnels. During an 8″ snowstorm, CJGeo abandoned both tunnels in a single day. The unoccupied building was grouted via holes drilled through the floor. The tunnel below the occupied building was free sprayed from inside the tunnel. All tunnels were kept under negative pressure ventilation in order to address installation odors.

CJGeo placed 4100 pounds of polyurethane grout into the two tunnels.

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Facing a similar challenge to this project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

Office Floor Settlement Repair

The Job

This office floor settlement repair project is located near Norfolk, Virginia. The slab floor inside of a grain import/export facility office sank both differentially and globally. All exterior walls are on driven timber piles, but the floor floats independently of the foundations. Slab settlement up to 3 inches affected approximately half of the building footprint.

The Challenge

Over the roughly 15 years that the floor was settling, maintenance crews were constantly repairing various systems. These repairs were including tuckpointing CMU walls, moving/shimming HVAC ducting, and rerouting water lines.

The foundation repair work on this building couldn’t impact operations. Ship loading and unloading could not be disrupted for any reason. The settled building houses many operations critical to ensuring timely loading and unloading.

The Solution

CJGeo proposed polyurethane grouting for this slab foundation repair project. Polyurethane grouting is safe, fast, and economical for floor settlement repair. Structural polymer grouting is another name for polyurethane grouting. The material of choice was CJGrout 28FDL. 28FDL is optimal for lifting light duty commercial floors experiencing both global and differential settlement.

CJGeo mobilized two polyurethane grouting crews to the facility on a Saturday morning. The 4,000 square foot repair only took nine hours start to finish. There were zero disruption to operations. During lifting, previous cosmetic repairs were undone to facilitate lifting. This included removing extensive patch material from the CMU walls, loosening plumbing connections, and adjusting HVAC ductwork.

By mobilizing multiple crews with multiple equipment redundancies, CJGeo was able to ensure that the repair had zero disruptions to the facility and its operations.

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Facing a similar challenge to this office floor settlement repair project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.

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