Carbon Fiber Structural Repair Exterior Block Wall

Problem

This concrete masonry building had experienced cracking damage at the corners and around window and door openings. The building was occupied by several different businesses, including a Montessori School, infant daycare, and retail storage area.

Y2 Consultants of Jackson Wyoming conducted an assessment including an infrared scan of the building that revealed construction deficiencies. The structural assessment of the building noted that the cracks were due to differential loading and insufficient horizontal rebar at the corners to tie the perpendicular walls together.

The differential loading and insufficient rebar had stressed the CMU to crack in these loca-tions. In order to allow safe occupancy of the building, it was determined that a retrofit of the deficient areas was necessary. Repairs would need to be coordinated with the businesses using the building, without a lot of disruption.

Solution

A Carbon fiber retrofit repair process to strengthen the walls at the cracked corner areas was determined to be a viable solution. CST’s carbon fiber repair system is comprised of high strength carbon reinforced fabric strips, applied over a clean and prepped surface, and adhered using a high strength epoxy. CST crews first prepped the surface using surface grinders to remove existing paint and get the surface profile required. A boom lift was used to help the crew safely reach areas above the awning. CST power washed the exterior of the building where the carbon fiber reinforcement would be applied. Moisture tests of the block surface were taken to ensure project specifications were met for the surface conditions necessary to achieve maximum adhesion properties of the material. Once dry, primer, then a tack coat, and then saturated carbon fiber was applied to the wall followed by a final grey UV exposure rated coating to protect the material.

Result

CST crews successfully reinforced deficient and cracked areas of this concrete block building in a matter of days.
The carbon fiber retrofit allowed the owners to keep business running and provide additional support to extend the useful life of the building for many more years. Carbon Fiber repair options such as the method used on this concrete masonry building strengthen existing structures, and provide a higher safety factor.

For many older structures, where reinforcement may not have been included during construction, carbon fiber retrofit helps to stabilize and reinforce areas of concern, bringing older buildings up to current code regulations and extending their useful service life.

CHALLENGES

  • Perform the repair without disrupting tenants of this commercial building.
  • Prepping the surface to meet specification for maximum adhesion of the car-bon fiber material.
  • Accessing areas above the awning of this structure to prep surface and install carbon fiber material.

BENEFITS

  • In situ, non-disruptive repair.
  • Increased safety factor through strengthening of existing structural deficiencies.
  • Meeting current code regulations, allowing older buildings to continue to be used.

Granby Foundation Lift & Stabilization

PROBLEM

Located in the mountains of Colorado, this 15 year old residence had settlement occur in the foundation, and resulting damage to exterior facings, windows, doors and casings as well as interior damage to drywall and wall finishes. 

The owner had recently purchased the home and was referred to CST by a previous customer. CST was contacted to assess the issues with the foundation, and provide a solution to repair the settled foundation and mitigate against future settlement. The homeowner wanted the repairs made on the foundation prior to beginning additional mechanical and cos-metic repairs such as replacing cracked windows, doors, and interior/exterior finishings which needed to be completed soon as cracks and gaps were causing issues with keeping the cold winter air out of the home. 

SOLUTION

An initial site elevation survey conducted by CST revealed that the home’s foundation had experienced settlement of approximately 2 inches. 

The biggest area of differential movement had occurred in the great room and front entrance areas of the home. 

CST performed Soil Density tests in order to determine the weak soil zones and set benchmarks prior to designing the injec-tion plan. Once injection locations were determined, CST installed a high density expanding structural polymer into the soil, at determined depths. Working from the exterior, with crew members monitoring from the interior great room, the team lifted the settled areas back to original elevation. 

RESULT

The entire repair of this home’s foundation was completed in less than 2 days. CST lifted the settled foundation without causing additional damage to the home and adjusted windows enough that they were able to be latched where previously they had not. 

CST’s repair process is non-invasive and the residents were able to stay in their home during the repair. 

By stabilizing the foundation’s underlying soils, the home was protected against any future settlement or movement, allowing the owner to quickly move forward with completing the mechanical and cosmetic repairs to their home. 

CHALLENGES

  • Completing foundation repair in mid-December in order to protect the interior of the home and it’s occupants from winter elements. 
  • Lift the foundation without causing additional damage to the home’s finishes. 

BENEFITS

  • In Situ, no excavation foundation repair. 
  • Repairs are completed quickly, with very little disruption or mess. 
  • Families may stay in their homes during repair. 
  • Effective and efficient, long lasting protection for your assets. 

Concrete Slab Lift Asphalt Pavement Lift Soil Stabilization – Pueblo, CO

This highway roundabout located in Pueblo West, Colorado had experienced settling of between 2 to 3 inches in areas of the concrete panels. The settlement had occurred as a result of poorly compacted soils. The settlement of the slabs had created a negative drainage situation, causing water to pool against the curb and gutter instead of draining away from the structure as originally designed.

As part of a larger paving project, Martin Marietta, a heavy highway contractor working on the section of roadway that included this roundabout, needed a solution to lift the settled concrete panels and correct the drainage issues the settlement had caused without ob-structing traffic flow through the rounda-bout and connecting roadways.

CST partnered with Martin Marietta to create a repair plan that would allow traffic to continue to flow through the roundabout while the panels and adjoining asphalt were lifted back to original profile. CST’s technologies were used to repair the settled slabs and pavement. The process employs injecting an expanding structural polymer that densifies and compacts soil, fills voids, and lifts settled concrete and asphalt. A rubberized barrier was used to assist injection crews in staging and protecting injection hoses across the roadway which allowed traffic to safely continue through the roundabout during the repair process. Martin Marietta used a water truck to wet down the roadway and panels to assist CST’s injection crew in locating and correcting the areas of settlement prior to beginning injections.

The settlement and soil compaction issues were efficiently and effectively addressed and corrected while allowing traffic to continue use of the roundabout and roadways during the repair. The con-crete panels and adjacent asphalt pavement were lifted back to original design profile which corrected the drainage problem.

The repair was completed in less than a day, preserving the existing concrete, correcting drainage, and guarding against future damage erosion, settlement, or damage to this roundabout structure and adjacent roadway.

CHALLENGES
Maintaining traffic flow during repair.
Safely staging injection equipment in the roundabout area.
Restore drainage away from the concrete panels.

BENEFITS In situ, no excavation repairs
Little to no downtime
Fast, cost -effective, permanent
Preserves and extends the life of existing structures & pavement

Union Pacific Railroad Crossing Lift Realignment and Soil Stabilization

A Union Pacific Railroad Crossing at the entrance of the Mountain Cement plant located in Laramie Wyoming, had experienced settlement of the precast panels beneath the track.

A soft spot beneath the panels and the presence of water had exacerbated settlement and caused the crossing panels to become misaligned.
Ed Hinker, Union Pacific Track Maintenance Manager, contacted CST to analyze and create a repair plan to provide in situ stabilization and realignment of the crossing.

Due to the location of the crossing, it was imperative that repairs be made quickly, without a lot of disruption to both truck and train traffic utilizing the crossing.

CST partnered with UP maintenance personnel and designed a site specific injection plan to stabilize the soft soils, lift, and realign the precast crossing panels, as well as beneath additional areas of track.

A thorough site investigation was first conducted to identify areas and depths for repair.

CST’s technicians placed injection probes into predetermined locations and depths, installing a high density, expanding structural polymer to stabilize the soft spots in the soil, and lift to realign the settled crossing panels.

Additional areas of subgrade soil were also treated in adjacent track sections leading up to and away from the crossing.
The railroad crossing precast panels were lifted, realigned, and stabilized in a matter of hours. The subgrade soils beneath the panels and areas of track were stabilized to mitigate against additional settlement.

Repairs were made with zero excavation and very little disruption to vehicles accessing the cement plant, or trains utilizing this section of track.

All areas were immediately available for use following the repair.

CST’s soil stabilization and concrete lifting technologies are an efficient and effective way to provide long term, precision repairs without the added expense of lengthy downtime or costly tear out and replace alternatives.

Riverton Utah Commercial Void Fill and Soil Stabilization

In early February of 2018, a major water line break caused significant voiding be- neath the floor slab of a large commercial retail warehouse in Riverton UT. The pressure of the water was so great, in addition to causing large voids beneath the floor, it actually cracked the slab, and push water through the control joints in the concrete, flooding portions of the store. Scott Davis with Kleinfelder Engineering contacted CST concerning the damage, looking for an in situ solution to fill the voids. Soil testing performed after the water line break revealed that the soil compaction beneath the floor was good, but the voided areas would need to be filled. The solution would need to be performed without having to move permanently installed shelving units and merchandise and be completed without a lengthy closure for the business.

CST partnered with Tradesmithe Property Management and Kleinfelder Engineering to design an in situ repair plan to fill the voids and provide continuous , uniform subgrade support. The solution needed to provide a minimum of 6,000 PSF compressive strength of the soil and maintain dimensional stability for the life of the structure. CST’s in situ soil stabilization technologies employs a high density, expansive structural polymer injected through small holes directly through the floor slab and into the subgrade soils. The polymer, in it’s liquid state travels along finding voided areas and expands to fill and re-compact the compromised soil. Injection holes are very small and are filled with grout once repairs are complete. Once cured, the polymer reaches a much higher compressive strength that easily exceeded what was required for this project.

Once all voided areas were identified and marked, CST installed ESP material and completed void fill on a total area of 26,000 SQ FT.  All repair work was completed in 3 nights, allowing the business to stay open during the day.

Due to the highly advanced injection techniques and equipment, permanent shelving units and merchandise did not have to be moved in order to make the repairs.

The repair process efficiently and effectively restored compaction to the sub- grade soils and provided a solid solution to extend and preserve the useful life of the floor slab and structure.

CST’s polymer injection process does not require excavation and is environmentally friendly while providing fast, clean, permanent results.

  • Locate all voided areas and complete repairs without moving permanently installed shelving features and
    merchandise.
  • Permanently installed shelving, fix- tures, and appliances could not be moved during the repair.
  • No excavation required.
  • Environmentally friendly.
  • Little to no disruption to business.
  • Extends the useful life of existing slabs and structures.

Campbell County Detention Center – Gillette, WY

Concrete Stabilization Technologies, Inc., partnered with Campbell County Public Works Department and CEI Engineering, to repair the foundation of the Campbell County Detention Center in Gillette Wyoming during the summer of 2001.

Column Stabilization, Interior Wall Lifting, Floor & Thickened Slab Lifting, Void Fill, and Soil Densification were preformed in the facility to correct a number of settlement issues. Crews began on the outside columns of the building, lifting and stabilizing exterior columns. Using the CST DI process, the soil was stabilized around the columns, voids filled, and columns were placed back on original center. Post testing of the soils in the area proved significant increase in the soil densification, arresting any further settlement issues from occurring. Crews continued work inside the facility, with injections placed to lift and stabilize the floor slabs and lift walls back to grade.

Work performed at the Campbell County Detention Center was done during normal hours of operations, with very minimal disruption to staff or residents of the facility. Security of the residents was not compromised due to the non-intrusive methods and procedures employed by the CST technology. Work was performed in situ, and by utilizing the CST technologies, Campbell County not only saved money by avoiding a rip out and replace scenario, but also avoided the hassle of having to relocate residents and staff. The project was completed on time and below the original estimate. Repairs made to the Campbell County Detention Center over a decade ago, are still holding strong!