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

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.

Colorado Bridge Approach Slab Settlement Lift

Bridge Approach Slab Settlement Repair – Crystal Valley Parkway, CO

Asphalt Pavement Lift of a Bridge Departure where the Subgrade had settled and the pavement needed to be lifted

In Castle Rock, CO, along the Crystal Valley Parkway, the Town of Castle Rock, CO was experiencing bridge approach slab settlement of 1,900 SF of bridge approach, departure, and sleeper slabs on two bridge ends and adjoining pavement. Settlement of adjacent sidewalk had also occurred causing an unsafe driving situation as well as dangerous conditions to pedestrians utilizing the crossover sidewalk area. The unstable subgrade reaching below the sleeper slab would need to be treated to stabilize the area before mill and fill of asphalt pavement could be performed.

Bridge Approach Slab Settlement Solution

CST partnered with the Town of Castle Rock, utilizing their Deep Injection process to treat unstable soil, lift the slabs, and realign sidewalk and pavement areas. Dynamic Cone Penetrometer soil tests were performed to correctly identify the weak soil zones. Injection tubes were placed at depth and expanding structural polymer injected to densify and provide stabilization of subgrade soils. Once the soil is stabilized, injections are continued to provide lift and realignment of the slabs and overlying pavement. The CST Deep Injection process provides proper support to the soil and heavy sleeper slabs to mitigate against future bridge approach slab settlement and movement, while also providing a solid subgrade for pavement.

Repairs were made in two shifts while allowing traffic to continue utilizing the area vs. time and money spent to reroute. Foundation soils were significantly strengthened to mitigate against future settlement. Bridge approach and departure slabs were lifted back to original elevation as well as stabilization and lift of sidewalk areas. Subgrade soils were quickly and effectively stabilized to provide a strong base for asphalt pavement mill and fill operations. The added benefit of water cutoff effectively arrests soil erosion within the area. Significant savings to municipalities and tax payers vs. alternative methods of rip out and replace. Extended use life of the bridge, sidewalk, and pavement.

Culvert Annular Void Fill

Utah DOT Culvert Annular Void Fill

Objective of this project was to fill annulus between culvert and surrounding embankment. The outer pipe was rusted out at the bottom and water was leaking in between the two pipes and coming out bottom of joint. Goal was to seal leaks in an outer pipe, surrounding smaller pipe and fill voids.

Critical elements of this project were dealing with the rusted out bottom of the outer surrounding pipe. Large amounts of water needed to be pushed out and fill resultant voids to assure pipe support and stability.

Douglas County Sheriff MSE Wall Repair – Highlands Ranch, CO

Douglas County Sheriff MSE Wall Repair – Highlands Ranch, CO

Concrete Stabilization Technologies, Inc. partnered with the Douglas County Facilities Management division of Douglas County, CO to stabilize the MSE walls at the Douglas County Sheriff Sub-Station in Highlands Ranch, CO.

CST was referred by a geotechnical engineering firm to provide a solution to stabilize portions of distressed MSE wall. The geotechnical report indicates low density soils between base of wall and top of storm sewer pipe installed approximately 16’ prior to MSE wall. A section of the MSE wall was slated to be rebuilt after soil stabilization project was completed.

Patented processes were used to increase bearing capacity and stabilize the West and East MSE wall in the sewer trench area of the facility for an area of approximately 60 LF. CST’s deep injection method was performed to reinforce low density soils between top of storm sewer pipe and bottom of MSE wall. The distressed MSE wall was monitored with laser levels during the injection of expanding structural polymer into the underlying soils. Injections were also performed around a manhole to void fill and seal joints.

Video camera inspections were done before and after injection to verify pipe condition. The patented injection processes used in this stabilization project saved the customer from excavating and possibly replacing the pipe.

This project was completed on time and on budget!

Salt Lake City Industrial Road Restoration – UT

Patching, Diamond Grinding and Joint Resealing

Located close to downtown Salt Lake City, Industrial Road at California Avenue needed some well deserved repair. Industrial Road is a critical concrete pavement thoroughfare for industrial traffic and heavy duty trucking in the area as it is located adjacent to a major truck stop and trucker fuel depot. The majority of the concrete pavement was structurally sound but, due in part to sub-grade softening caused by surface water intrusion through the joints, the pavement exhibited differential settlement between the slabs measuring up to 1.5-inches. The combination of constant heavy truck traffic and the presence of water in the sub-grade facilitated continued erosion beneath the slabs.

Although the owner, the Salt Lake City Corporation, considered replacing all concrete slabs. They opted instead to preserve the existing concrete. After all, only 10 percent of the slabs showed cracking. The methods chosen for repair were soil foundation stabilization, slabjacking, slab replacement, stitch-in-time crack repair, dowel bar retrofit (DBR), diamond grinding and joint resealing. A total of 326 dowels were retrofitted on the 1,461 square-yard project. A series of 5/8 inch holes were drilled through the slabs to facilitate the injection of high density expansive polymers into the sub-grade soil to a depth of 3.5 feet. With the deep injection process complete, the same polymers were then injected at the slab/sub-grade interface through the same 5/8-inch holes to fill fissures and voids as well as to lift each concrete slab to match the elevation of adjacent slabs. This process minimized the differential settlement between the slabs. Additional lifting was then employed beneath the slabs to create a 1.5 percent drainage slope from the crown of the road to the curb to facilitate better drainage and safety.

This design engineer decided to test an innovative new crack stitching procedure utilizing polyurethane material and fiberglass panels. The CST Stitch-In-Time process was selected and used beneath five slabs that contained minor cracks. Following the slab stabilization and lifting operations, the Stitch-in-Time process required the placement of ½ inch fiberglass panels (stitches) within saw cuts made perpendicular to the slab crack. The cuts were then filled with clean pea gravel and an acrylic bonding material was poured into each cut. Four stitches were placed in each candidate slab.

Following the stabilization, lifting and stitching operations, the retrofit dowel bars were installed in the slabs, severely cracked slabs were removed and new concrete was placed in the necessary areas. Once the concrete was fully cured, the entire area was diamond ground to remove remaining surface defects, increase smoothness and provide a safe, high friction wearing surface. The joints between the slabs were then cleaned and resealed to prevent the intrusion of water and incompressible materials. As a final step, a sealing compound was applied to the concrete surface to provide additional protection.
Another challenge was slab cutting at the joints prior to the lifting process. The summer heat caused slab expansion, which can bind the saw blades and restrict a slab’s upward movement. To prevent this occurrence, a chisel-shaped device was inserted into the saw cut adjacent to the trapped blade and pressure was applied to spread the cut sufficiently to allow the blade to be extracted.

The project was scheduled for 90 days but was completed in a mere 62 days and was under budget. As a result of this successful project, the owner has chosen to use concrete pavement preservation on future projects within the city. The combination of using high density expansive polymers in conjunction with other concrete pavement preservation techniques including dowel bar retrofit and diamond grinding should extend the life of this pavement for approximately 15-20 years.
According to Mike Kendell of SLC Engineering, “Ride quality was greatly improved and Salt Lake City is satisfied with the results.”