PU Grouting & Injection

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Grouting

 

Our specialty Grout is designed for sealing high flow / high pressure ground water where the washout effect on other types of grout is predominant. It is extremely penetrable and once coagulated, extremely flexible. Future ground movement or shocks from blasting or excavation will not result in water leaking again. Sealed single leaks with flow rates of 2600 GPM and inflows with pressures of 2500 P.S.I.

 

It is a continuous medium colloidal polymer grout. It is injected in a fluid state and remains a fluid until activated. The grain size of the particles in the polymer is very small (in the colloidal range), and the viscosity of the polymer is quite low. Hence, the milk-like polymer at the time of injection is extremely penetrable and will go where water travels.

 

Inhibitors and activators are used to change the characteristics of the polymer, enhancing the control over direction of flow and resulting in greater penetration. The polymer remains stable in its fluid state until activated. Activation may also be achieved through agitation when the polymer is subjected to shear action as it passes through an orifice of a fissure. Once activated, the dispersed colloidal compound coagulates to form a mass of linked and tethered rubberlike laths.

 

When first formed, the activated polymer transforms to a hydrated jelly–like plug of matted laths. As pressure is applied to the activated polymer, the water is expelled and the laths adhere to each other to form a denser and more competent plug that is both impenetrable and flexible.

 

Our specialty Grout is non-toxic and user friendly. It is not exothermic – no heat is generated during the curing process.

 

The plug will remain effective even when movement occurs. Future ground movement or shocks from blasting, reaming or excavation will not result in water leaking again, as may happen if only cementitious grouts were used.

 

In recent years, interest has grown in the application of Grout for containment of groundwater at nuclear sites in the United States and Japan. Testing on the grout involving exposure to varying doses of radiation were performed in 2014, and the maintenance of the grout’s physical properties demonstrated the grout’s very good radiation tolerance. Field experimentation on injection methods is now underway to determine optimal ways to create subsurface containment structures with our Grout.

 

Grouting Properties

 

  • Extremely permeating – Particle size less than 1 micron.
  • Remarkable spread – Initial injection viscosity is only 2.5 cP.
  • Does not wash out under high flow/high pressure conditions.
  • Controlled curing rates from 2 seconds to several days.
  • Works in saline and hypersaline formation waters.
  • Remains flexible after solidification. 350% Elasticity.
  • No heat generated; reaction is not exothermic.
  • Safe to work with and environmentally friendly.

 

Method of Injection

 

Grouting is injected into a water bearing crack or fissure via a hole drilled intersecting the flow. A multi-port injector is inserted into the hole through which the Grout and/or additives are injected. More than one may be drilled for injection purposes. Generally, in situations where the flow velocity is moderately low, Grout will be sufficiently activated by agitation alone – stopping the flow. In high flow situations, chemical activation may be required.

 

Whereas the addition of activator results in Grout becoming unstable, followed by rapid coagulation, the addition of an inhibitor increases the stability, thereby reducing its tendency to coagulate when subjected to agitation. This enables the grout to be transported for greater distances through the formation before solidifying. The exact instruction is site specific depending on Lugeon, Water Take, and Dye connection tests and will be detailed in the site specific Safe Work Instruction (SWI)

 

Advantages

 

  • Environmentally friendly – non Hazardous
  • Chemically selective – will seal water in oil wells but not hydrocarbons / crude oil.
  • Radiation Tolerant.
  • Reaction is non – exothermic.
  • Viscosity: 2.5 cP (1.5 cP while grouting – miscible in water).
  • Remains flexible once solidified and will not re-leak with ground movement – (350% elasticity).
  • Extremely permeable – forms Hydro colloidal solution in water. Particle size less than 1 Micron – (0,6 Nanometer)
  • Curing can be chemically controlled from as short as 2 seconds to several days.
  • Seals saline and hyper saline water effectively.
  • Performs well when pre-grouting shafts declines and pilot holes – due to extreme penetrability.
  • Exceptional performance under high water pressure – successfully sealed static head of 2900 P.S.I.
  • Durable – no re-leak occurred during 40 years of grout history.
  • Does not wash out during grouting – sealed leaks of 50 Gallon /second successfully.
  • Saves money on drilling costs due to super efficiency of grout spread.

 

Usage

 

  • Reactive Grouting
  • Permeation Grouting
  • Curtain Grouting
  • Remedial Grouting
  • Back wall Grouting
  • Pre-Grouting

 

It has been successfully used in many different environments including the following:

 

  • Nuclear Power Reactors and depository waste sites
  • Basement parking garages
  • Water inflows in deep mines (Up to 2,5 mile vertical)
  • TBM and lined tunnels
  • Underground dam sealing
  • Fresh water, Brackish water and Brine.
  • Methane gas sealing
  • Underground military sites, Silos and bunkers
  • Bulkhead sealing
  • Underground waste depository sites.
  • Retaining walls
  • Reservoirs and Dams
  • Water Plugs
  • Pipelines
  • Joint and crack repair
  • Salt mines – briny conditions
  • Ore passes
  • Lift wells
  • Shaft sealing – ventilation shafts / raised boreholes
  • Hard rock, Soft rock and Sand environments
  • Water ingress into open cut mines
  • Geological features – fissures, aquifers, cracks voids

After Grouting