Concrete Crack Injection Polyurethane
Introduction:
Maintaining the design integrity of concrete structures is paramount, particularly when it comes to preventing water intrusion and ensuring long-term durability.
Leaking concrete cracks pose a significant challenge across various infrastructures, necessitating advanced and reliable repair solutions.
Concrete Crack Injection with Polyurethane (PUR) Water Stop Foam Injection is a modern and economical approach designed to effectively seal leaking concrete cracks permanently. Chosen for its efficacy and adaptability, this method addresses a wide range of issues associated with water damage, including structural erosion and the presence of efflorescence.
Highlighting the procedure and it’s benefits, this article is an introduction to leveraging PUR Water Stop Foam Injection to maintain and enhance the integrity of concrete constructions, ensuring long-term protection against the elements.
How to Seal Leaking Concrete Cracks with PUR Water Stop Foam Injection
Zoo Exhibit Crack Repair — The Gorilla Exhibit at Omaha’s Henry Doorley Zoo was closed for renovations and repairs, including the sealing of concrete cracks that had shown signs of water intrusion, structural erosion, and visible stains from rust and efflorescence.
Concrete crack injection with polyurethane foam resin was the choice of repair to resolve water bearing crack leaks. Crack related damages were located at a walkway under a lofted area with multiple windows and decorative shotcrete structures where gorillas could sit and be viewed by people walking through the exhibit.
The cracks were covered in efflorescence could be seen on the walls below the lofted area as well as cracks coming off the cold joints around the precast window framing.
The crack dimensions ranged from hairline to 1/4″ joint seams with varying degrees of water intrusion and active leaks causing heavy efflorescence build up. The roof and lofted area collect and feed water during snow melt and heavy rains.
SealBoss provided an on-site technical representative to consult with the contractor on injection methods using NSF/ANSI 61 Drinking Water Contact Certified injection grout, a high-pressure injection pump and mechanical injection packers.
Concrete Crack Injection – Polyurethane
Which products are shown in the video?
- SealBoss Injection Packer Evolution 1/2″ inch (16mm) Aluminum
- SealBoss 1510 Water Stop Foam PU / NSF/ANSI61
Concrete Crack Injection Polyurethane – Procedure and Repair Method
Prior to injection, the contractor had to first prep the cracks by removing any efflorescence and dirt build-up from the face of the crack using a wire brush.
Once the cracks were visible an injection plan was established to address the leaks working from the low point up.
Using the SealBoss high pressure concrete crack injection system — hydro-active, hydrophobic polyurethane foam resin, injection packers and polyurethane crack injection pump — hydro-active foam resin is injected into the cracks, expanding on contact with moisture and displacing any water in the process while creating an airtight & watertight seal.
Crack Injection Details
A – Standard Injection Procedure
One side of the lofted area had three significant cracks that resulted in substantial active leaks. The east wall presented larger actively leaking cracks. Further, cracks and cold joints from a precast window frame created an area of leakage that needed to be injected.
In those areas, SealBoss 1/2 inch injection packers were placed according to SealBoss Standard Recommendations, roughly 4” from the crack in ½” holes that were drilled at a 45-degree angle back into the crack. SealBoss 1510 Water Stop Foam was injected until positive refusal of the hydro-active resin was visible from the face of the crack as well as on the exterior side of the wall when a through crack was injected.
Starting with the lowest point of the cracks, SealBoss 1510 Leak Sealing Foam Grout was injected until positive refusal was observed on the interior and exterior of the wall. Due to the temperature of the wall, around 36 degrees Fahrenheit, the contractor was advised to condition the resin to room temperature prior to use as well as adding 15% of SealBoss 1510 Accelerator/Catalyst to compensate for the cooler ambient and substrate temperature — cold temperatures slow down the chemical reaction of the injection grout.
B – Custom Injection Procedure
In some areas, more complex leaking cracks and cold joints had to be sealed, requiring a deviation from standard injection packer placement.
Multiple cracks had developed connecting to a larger initial crack, creating a spider-web crack pattern. Due to the complexity of the crack system and intersections of cracks, the injection procedure was modified from the standard alternating “zipper” pattern typically recommended. Cracks were so close in proximity that packers needed to be strategically ‘custom’ placed to increase the chance for each packer drill hole to successfully intersect with the crack — resulting in a less orderly packer placement pattern.
Starting at the low point of crack, the Water Stop Foam was injected till and foam travel was observed at a distance from the point of injection intersecting into other cracks. This meant that multiple cracks could be addressed from one point of injection without the need for drilling too many injection port holes.
As the resin visibly moved up and out of the face of the crack, injection of that specific crack would be stopped so the resin could react and fully expand creating a seal.
Shortly thereafter, a secondary injection of the same packer was performed to penetrate even deeper into the crack and allow for further continuation of visible vertical foam resin travel.
Cleanup
After the cracks were successfully injected, the injection ports were removed, and a hydraulic cement patch was used to patch the ½” dill holes.
Products Used:
Injection Resin:
- Injection Resin: SealBoss 1510 w/ 15x Accelerator – NSF/ANSI 61 Drinking Water Contact Certified PU Foam\
- Injection Packers: 1/2” 13-100 Evolution Aluminum Packers
- High Pressure Pump: P2002 Single Component Injection Pump
- Cleaning: R70 Pump Flush
Other Tools Used
Cleaning Materials: Xylene, rags, bucket
Additional Tools: 18” x 1/2″ drill bit — 3/8” Crescent Wrench — Dead Blow Hammer
Hammer Drill — Access 110v Power —
Vacuum
Heat Gun
Call Your SealBoss ® Technician
If you have any questions on crack injection water stop procedures or any injection related applications, please contact our team of qualified SealBoss representatives to schedule an on site consultation & full injection systems training. Call us at 714-662-4445.
