Injection Systems for Concrete Structure

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25 July 2019 - 11:55, by , in concrete repair, Concrete Strengthening, Waterproofing, Comments off

The Sika® Injection Systems for the different Applications

Waterproofing of Construction Joints

Sealing of construction joints in concrete structures

Sika® Injection-29

Low viscous, flexible and solvent-free polyacrylic injection resin with a high solids content. It is used for the injection of the Sika® Injectoflex Hose System.

Sika® Injection-2011

Low viscous, flexible and solvent-free polyurethane injection resin for permanent waterproof sealing of cracks and construction joints. It forms, in contact with water, a uniform, closed and therefore watertight pore structure. The reaction time of Sika® Injection-201 can be accelerated with Sika® Injection-AC20.

Sika® InjectoCem-190

Two-component injection grout for sealing and structural strengthening of cracks and construction joints, based on microcement with added admixtures and corrosion inhibitors. It is also used for the injection of the Sika® Injectoflex Hose System.

Surface Sealing of leaking Concrete Structures

Remedial surface sealing by curtain injection of defects in underground building components

Sika® Injection-304

Flexible, very low viscous and very quickgelling polyacrylic injection gel for permanent watertight sealing of leaking surfaces. The material reacts to form a waterproof, flexible but solid gel with good adhesion to both dry and wet substrates.

Waterproofing of Cracks

Closing, sealing and flexible bridging of leaking cracks in new and existing structures

Sika® Injection-101

Fast foaming, low viscous and solvent-free water-reactive polyurethane injection foam resin for temporary waterstopping. The material cures to a very dense hard-elastic foam with a very fine cellular structure. The reaction time of Sika®Injection-101 can be accelerated with Sika® Injection-AC10.

Sika® Injection-2011)

Low viscous, flexible and solvent-free polyurethane injection resin for permanent waterproof sealing of cracks and construction joints. It forms, in contact with water, a uniform, closed and therefore watertight pore structure. The reaction time of Sika® Injection-201 can be accelerated with Sika® Injection-AC20.

 

Structural Crack and Void Repair

Bridging and filling of cracks and voids where structural strength is required

Sikadur®-52 Injection2

Low viscous, solvent-free, high strength epoxy resin for structural bonding of cracks and voids in dry and damp concrete structures.

Sika® Injection-451

Ultra low viscous, solvent-free, high strength epoxy resin for structural bonding of cracks and voids in dry and damp concrete structures.

Sika® InjectoCem-190

Two-component injection grout for sealing and structural strengthening of cracks and construction joints, based on microcement with added admixtures and corrosion inhibitors.

Waterproofing of damaged Membranes

Repair by injection of damaged waterproofing membranes (single and double layer systems)

Sika® Injection-305

Flexible, very low viscous and quickgelling polyacrylic injection gel for permanent watertight sealing of damaged membranes (single and double layer systems). The material reacts to form a waterproof, flexible but solid gel with good adhesion to both dry and wet substrates.

Waterproofing of Foundation Pits

Sealing of water-bearing cracks and joints in retaining walls of foundation pits

Sika® Injection-105

Fast foaming, low viscous and solvent-free water-reactive polyurethane injection foam resin for flexible waterproof sealing of leaking foundation pits. The material cures to a very dense flexible foam with a very fine cellular structure.

 

Sika’s Ecologically Advanced Injection Systems

Sika® Injection systems have been tested by independent institutes with respect to the potential risks concerning water quality, working safety and toxicology. These tests give information on how the liquid materials i.e. immedately after injection, or the hardened /cured material affects the quality of water.

Sika® provides full environmental reports on Sika® Injection-101/-201/-203/-304/-29.

 

Application of the Sika® Injection Systems

Crack Injection with Mechanical Packers

1. Drill packer holes at a 45° angle to the concrete surface as shown in the figure.  of drill hole =  of packer + 2 mm.

2. Install the mechanical packers. Tighten the mechanical packers so that they can withstand the maximum injection pressure.

3. Fix the non-return valve on the first packer and start the injection process.

4. When the injection material flows out of the second packer during the injection process, fix the non-return valve on it as quick as possible. Stop injection at the first packer and continue at the second packer.

5. Repeat this procedure from packer to packer.

6. If necessary, a secondary injection procedure is carried out to ensure the crack is completely filled and sealed.

 

Crack Injection with Surface Packers

1. Prepare the substrate by blast cleaning or mechanically by grinding etc., then clean by brush and vacuum.

2. Place a steel nail through the packer into the crack to prevent the injection canal from being blocked by the Sika® Injection-490 adhesive and then install the surface packers as shown in the figure.

3. Patch the surface of the crack with Sika® Injection-490. Ensure that the packer and the crack on the surface are fully covered by the adhesive filler.

4. As soon as the adhesive has cured, remove the nail and fix the button head fittings (non-return) on the first packer and start the injection process.

5. Continue the injection procedure as for crack injection with mechanical packers (points 4, 5 and 6).

 

Curtain Injection

1. Drill holes for the mechanical packers through the leaking building component at a distance of 30 – 50 cm apart as shown in the figure.

2. Install the mechanical packers. Tighten the mechanical packers so that they can withstand the maximum injection pressures.

3. Fix the button head (non-return) fittings on the first packer and start the injection process at the lowest row of drill holes.

4. When the injection material flows out of the second packer during the injection process, fix the non-return valve on it as quickly as possible. Stop injection at the first packer and continue at the second packer.

5. Continue the injection procedure as for crack injection (points 5 and 6).

 

Injection Pumps and Packers for Sika® Injection Materials

Injection Equipment for Sika® Injection Resins and Microfine Cement Suspension

Sika® single-component injection pumps are universal injection devices suitable for a wide range of applications. They are designed for professional use in crack and Sika® Injectoflex-System injection. Sika® Injection Pump EL-1, EL-2, Hand-1 and Hand-2 are suitable for Sika polyurethane, epoxy and polyacrylate resins. Sika® Injection Pump PN-2C is specially designed for curtain injection. A two-component pump is required for these fast reacting polyacrylate gels. The individual components are introduced to the mixing head separately. The actual mixing process takes place in a static mixer located in the mixing head. The colloidal mixer Sika® Injection Mixer C-1 is needed for the complete and thorough mixing of Sika® microfine cement suspensions. Sika® Injection Pump MFC-1 is used for the pumping of Sika® microfine cement suspensions. It provides continuous pumping without separation of the suspension.

 

Sika® Injection Packers for different Applications

Sika® Injection Packers are filler necks used as connection pieces between the injection pump and the structure. Sika provides a full range of injection packers. There are two different types of packers:

Mechanical Packers

for high and low pressure injection where hole drilling is possible

Surface Packers

for low pressure injection, where drilling is not possible

 

Surface Sealing of a Leaking Shaft

Problem

An inadequate waterproofing system had been selected for a concrete shaft standing in groundwater. Water was infiltrating the shaft from several construction joints and damaging the electrical installations.

Injection Material Requirements

  • Very fast reacting injection material
  • Able to form a new permanent watertight sealing surface
  • Environmentally friendly

Sika Solution

Curtain injection with

  • Fast reaction polyacrylate gel Sika® Injection-304

Injection Equipment

  • Sika® Injection Pump PN-2C and Sika® Injection Packer MPR with button head fittings

 

Sealing of Cracks in a Basement

Problem

A basement garage which is built up of watertight concrete with waterbars, suffered settlement cracks in the structure after construction. Water was infiltrating because the garage was exposed to groundwater pressure.

Injection Material Requirements

First phase:

  • Fast foaming injection foam
  • Reacts only in contact with water Second phase:
  • Low viscosity
  • No shrinkage in subsequent dry conditions
  • Good adhesion to concrete
  • Environmentally friendly and chemically resistant

 

Sika Solution

Crack injection with

  • Fast reacting polyurethane foam Sika® Injection-101 for temporary waterstopping
  • Elastic polyurethane resin Sika® Injection-201 for permanent waterproof sealing

Injection Equipment

  • Sika® Injection Pump EL-2 and Sika® Injection Packer MPS

 

Sealing of Damaged Membranes in an Open-cut Tunnel

Problem

An open-cut tunnel below groundwater level was sealed with sheet waterproofing membranes and waterbars. Damage occurred during the construction period and went unnoticed until the tunnel began leaking. Fortunately the damage location was easily identified as the membrane and waterbars were formed into compartments.

Injection Material Requirements

  • Permanently elastic
  • Able to form a new permanent watertight sealing surface
  • Gel time able to be adapted to the specific requirements
  • Capable of reversibly absorbing (swelling) and releasing (shrinking) moisture

Sika Solution

Compartment injection through injection pipes with

  • polyacrylate gel Sika® Injection-305

Injection Equipment

  • Sika® Injection Pump PN-2C and Sika® Injection Packer MPR with button head fittings

 

Structural Crack Repair of a Bridge

Problem

Cracks with the potential to become a problem for the structural integrity occurred in the support piers of a motorway bridge due to the dynamic loads.

Injection Material Requirements

  • Different low viscosities for different crack widths
  • High mechanical and adhesive strengths
  • Suitable for both dry and damp substrate conditions

Sika Solution

Crack injection with

  • Low viscous epoxy resin Sikadur®-52 Injection for cracks > 0.3 mm
  • Ultra low viscous epoxy resin Sika® Injection-451 for cracks 0.1 – 0.3 mm
  • Epoxy patching material Sika® Injection-490

Injection equipment

Sika® Injection Pump EL-2 and Sika® Injection Packer SP

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