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Concrete Floor Repair Projects

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

Port Shed Floor Stabilization

THE JOB

This port shed floor stabilization project is located in Baltimore, Maryland. The 11″ thick slab floor of a storage shed at a port facility settled up to 6 inches. Exploratory coring & non-destructive imaging (GPR & microgravity) indicated there were extensive voids below the floor.

Previous work on the adjacent bulkhead uncovered extensive voids below the exterior footings (pile-supported) and multiple abandoned, but unfilled, pipes under the floor.

THE CHALLENGE

Due to relatively thin voids, which were all less than 6 inches, and void filling grout had to be highly mobile. However, this posed environmental challenges due should the grout make its way into an unfilled abandoned pipe and into the adjacent waterway. The owner did not want to lift the floor, so grouting had to be sufficiently low mobility to prevent runaways, but also fill all voids at an economical hole spacing.

THE SOLUTION

CJGeo proposed polyurethane grouting for this slab foundation repair project. The original design was for a 50/50 mix of polyurethane and cement grouting. CJGeo proposed a valued engineering proposal to perform all grouting with polyurethane. CJGrout 35NHV geotechnical polyurethane grout was proposed to balance mobility for completeness of fill and reaction time to avoid any runaway loss into the adjacent waterway.

CJGeo mobilized a two-reactor polyurethane grouting rig and installed approximately 6300lbs of polyurethane grout over a three-day period. Pneumatic rock drills were used to speed drilling.

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Facing a similar challenge to what CJGeo addressed on this port shed floor stabilization 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.

Commercial Floor Void Fill

THE JOB

This commercial floor void fill project is located in Manhattan. During a Local Law 11 inspection, the owner of a coop building’s first floor asked the GC to investigate a settled slab floor inside part of the building. The contractor began opening up a 2′ square hole in the floor. During this, all the debris was disappearing. After opening the hole it was apparent why. There was a 2′ to 3′ deep void around the entire perimeter of the building footprint.

THE CHALLENGE

Filling a 90CY void under the floor of an operating business can be a challenge anywhere. Complicate it with a 40′ x 10′ laydown area, Mid-Town Manhattan traffic, and cold winter temperatures, and you’ve got quite the challenge.

The cause of settlement was the consolidation of poorly placed fill, which was primarily construction debris. Lightweight void filling material is best to minimize future settlement of the underlying fill material.

THE SOLUTION

At the suggestion of an on-staff structural engineer, the general contractor’s project manager reached out to CJGeo about performing polyurethane grouting to fill the voids. CJGeo proposed using a low-exotherm, high mobility bulk void filling foam to fill the voids. 3′ deep voids are too deep to fill with most polyurethane grouts. A true low exotherm foam is needed for efficiently and safely filling any voids thicker than about 6″. High mobility foams are also critical when filling voids in order to ensure complete coverage.

CJGeo mobilized a two-reactor polyurethane grouting rig. The CJGeo crew installed approximately 4800lbs of CJGrout 20SDB geotechnical polyurethane grout over a two-day period. CJGeo pulled continuous negative pressure on the void through the floor. This was to allow for continuous operation of the facility during grouting. CJGeo’s work didn’t disturb operations at all. All of the voids were completely full of grout at the end of the project. The polyurethane grouting process used here for slab foundation repair is sometimes also called slab jacking or structural polymer grouting.

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Facing a similar challenge to this commercial floor void fill 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 Water Intrusion Repair

The Job

This warehouse floor water intrusion repair project is located in Columbua, South Carolina. An area of the floor inside of a produce processing facility experienced water intrusion through joints in the floor. Considerable amounts of process water were dumped on the floor each day, and unsealed joints in the floor allowed water to collect under the floor slab.

The floor was showing signs of slab curl from poor control of the curing process after placement. With dynamic loading from material handling equipment, water was pumping through the joint onto the floor. Due to the slab curl, the floor was effectively acting as a diaphragm pump. The facility’s health & safety staff was concerned that the water could introduce contaminants to the food processing area.

The Challenge

The proposed repair had to perform well in saturated conditions, allow for near immediate resumption of material handler equipment, and ensure a long-term fix. Since no settlement had occurred, the grout material had to be able to seal the very small voids, displace water, and not exert any lifting forces on the floor.

The material & process also had to be perform well at cold temperatures–the facility is at 34 degrees year-round.

The Solution

CJGeo proposed chemical grouting using a hydrophilic prepolymer grout. Chemical grouting is ideal for saturated environments and helps to ensure complete stabilization and sealing of floors.

A single CJGeo chemical grouting crew mobilized to the site and performed the slab foundation repair work in a few hours. The water intrusion grouting work started after the second shift. The grout set to tolerate material handling equipment before the start of the first shift.

The following day, the facility reported no water extrusion under material handler traffic.

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

Industrial Facility Floor Repair

THE JOB

The slab floor inside of a manufacturing facility in Hagerstown, Maryland settled. This caused equipment that was installed on the slab to become misaligned, requiring industrial facility floor repair.

A geotechnical investigation revealed voids below the slab due to the settlement of the underlying soil. The affected area was built over approximately 10 feet of fill during construction. Engineering analysis showed that the soil was likely poorly compacted, but had consolidated with time.

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Polyurethane grouting

THE CHALLENGE

Due to the sensitive electronic equipment within the work area, the repair had to be very clean and dust-free. Though analysis determined that the underlying soils had most likely completed consolidating, the owner’s geotechnical consultant recommended limiting additional weight placed on the fill material.

The repair area was also more than 100 feet from the nearest exterior access. The floor had started to settle before the equipment was installed. It was very important that the slab not be lifted during the void filling process.

THE SOLUTION

Geotechnical polyurethane grouting to fill the voids below the slab floor. Polyurethane grouting is superior to mudjacking in situations like this because it is considerably cleaner, much faster, and allows for immediate reuse.  

The material used in polyurethane grouting is much lower weight than mudjacking grout. This reduces the weight applied to the underlying soil. Lower weight materials reduce the chance of resettlement.

A single CJGeo polyurethane grouting crew completed the industrial facility floor repair in less than a day, using CJGrout 20SDB. Due to the extreme sensitivity of the equipment to lifting, a specially-formulated plural component polyurethane grout was selected for undersealing without lifting.  

Precision equipment was used to monitor the floor during undersealing. A movement of 0.02 inches was used to determine the completeness of fill. This was confirmed by extensive extrusion of polyurethane through the adjacent saw cut control joints in the floor.

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

Grain Bin Floor Repair

THE JOB

The floor of a 105′ diameter grain bin settled. The floor had a bin sweep installed, that was mounted on the top of the unloading tunnel, which ran down the center of the structure. Where the slab floor butted up to the tunnel walls, the floor had settled 2″ on one half, and 3.5″ on the other half. This caused issues with operating the bin sweep because it was designed for a smooth, level floor.

The owner’s alternative was to remove the entire floor and pour a new floor. This would have been incredibly expensive and taken a very long time. The only access into the bin was two 2′ wide by 4′ tall doors, located 5′ above exterior finish grade, and 2′ above the bin floor elevation.

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THE CHALLENGE

Due to the nature of the commodity business, mobilization and completion of the grain bin floor repair had to be fast. Additionally, the repair had to return the floor to its original profile, along with the turned-down ventilation trenches in the floor. The extensive turned-down ventilation troughs made this floor very susceptible to cracking. The floor was 6″ thick but then went to 24″ thick at the ventilation troughs. Slabs with non-uniform thickness require extreme care and attention to avoid differential lifting.

The design loads for the floor are approximately 3500psf. So, the material used for lifting the floor had to be relatively high strength.

THE SOLUTION

CJGeo proposed polyurethane grouting for filling the voids below the floor and lifting them back into place. The minimum bearing capacity of the proposed materials was 5500PSF, ensuring adequate bearing capacity even under full load.

CJGeo mobilized two polyurethane grouting crews to the site. The concrete lifting work was completed over a period of two days. CJGeo placed more than 7,000 pounds of polyurethane grout using three reactors running simultaneously. Multiple reactors (pumps) helped to ensure thorough lifting of the slab and the ventilation troughs. The crews that completed this job have collectively performed millions of pounds of polyurethane grouting, ensuring the successful completion of this grain bin floor repair job.

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

Warehouse Floor Lifting

THE JOB

25,000 square feet of the industrial floor at a military facility settled up to 4 inches and was affected by sub-slab voids. This warehouse floor lifting project also included 250 track feet of embedded rail, which was set in an independent, thickened slab section. The building had been used for warehousing but was being transitioned to light manufacturing/maintenance.  

There were extensive voids below the floor. The voids were located with GPR, and confirmed with cores. Because the floor had cracked extensively as it settled, the designer called for a 4″ un-bonded overlay after stabilization.

THE CHALLENGE

The proposed repair method had to provide adequate bearing capacity for manufacturing and ensure complete void filling and stabilization.

THE SOLUTION

CJGeo provided a value engineering proposal to use geotechnical polyurethane instead of cementitious grout. The VE proposal was based on the following:

  • lower unit weight, so less likelihood of causing additional settlement
  • adequate strength to ensure uniform load transfer to the underlying soils
  • simplified logistics into a secure facility (all material delivered in just two truckloads)

The specified grout had an in-place density exceeding 115 pounds per cubic foot.  The proposed polyurethane grout, CJGrout 40NDV, has a constrained density of 5.5PCF, yet a bearing capacity exceeding 12KSF.

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CJGeo mobilized three polyurethane grouting crews to the facility, with a combined pumping capacity exceeding 5,000 pounds per hour.  CJGeo crews injected the CJGrout 40NDV through nearly 2,000 dime-size holes drilled in the slab to complete this concrete lifting project.

The cutoff criteria for void filling was cross-hole communication or 0.1 inches of lift. The settled areas of floor raised an average of three inches. The embedded track area raised up to four inches.

It took CJGeo fewer than 10 days to complete this warehouse floor lifting job. Because the material cures to 95% within a few minutes, the overlay preparation crew worked a day behind the polyurethane grouting crews.

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

9″ Floor Lift

THE JOB

9″ floor lift for 6,000 square feet of slab floor in a flex space building in Boston, Massachusetts. The tenant of a warehouse space vacated at renewal due to challenges that the settlement caused for their operations. The tenant of the adjacent office portion threatened to not renew if the warehouse floor wasn’t lifted.

THE CHALLENGE

The building owner wanted to lift the warehouse floor to improve the function of the space. To avoid further upsetting the office tenant, repairs had to be quiet, dust free, not require moving any of their furnishings, and ensure long term stability.

The office space settlement correction repairs could only happen at night, so relying on material deliveries would be difficult.

THE 9″ FLOOR LIFT SOLUTION

CJGeo proposed plural component polyurethane grouting to the owner for this 9″ floor lift. Plural component polyurethane grouting is exceptionally clean, isn’t dependent on third party grout deliveries, and allows immediately return to service.

A five person CJGeo polyurethane grouting crew corrected all of the settlement in a single shift using CJGrout 28FDL. The vacant warehouse portion of the building was lifted during the day. Once the adjacent office closed for the day, the CJGeo crew completed the office space slab foundation repair overnight.

CJGrout 28FDL injection uses 5/8″ holes drilled through the slab. Because the holes are so small, dustless drilling is very easy. During installation, CJGrout 28FDL expands up to 24 times its liquid volume. Therefore, this entire project was done with material delivered to the site in CJGeo’s equipment. Cement grouting would have required multiple material deliveries, which would have made this 9″ floor lift project take much longer.

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Facing a similar challenge to this 9″ floor lift? Give us a shout or shoot us a text. Click the state marker for the location of the project for contact info for the appropriate rep.

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