How to Seal Collection Systems Efficiently?
It was a brilliant idea of the inventors of the SANIPOR® Flood Grouting technology to let liquids defeat water migration through leaking collection systems. Fluid geo-technical grouts can automatically penetrate through leaks into pipe bedding materials - and make them watertight. All that has to be created, is a closed vessel which can be filled while hydrostatic pressure builds up - as the necessary injection force.
Flooding with fluid SANIPOR® components is comparable with the standardized leak testing with water (EN1610). From the initial to the final leakage rate the drop of liquid grouts are measured constantly during the execution.
The Procedure
Step 1
After a CCTV inspection survey and jetting, the section to be treated is plugged with inflatable plugs.
Manhole, sewer, laterals are filled with solution S1 which penetrates through defects into the surrounding ground.
The drop of S1 in the manhole is measured and recorded constantly.
After a duration time of 30-60 minutes solution S1 is rapidly pumped out, leaving defect zones saturated.
Step 2
After rapid flushing, the section is immediately refilled with solution S2 which reacts with S1 in the ground.
This starts to form a concrete-like matrix, binding soil particles and sealing all leaks with solidified ground around the defects.
The drop of S2 in the manholes slows down and is recorded in the sealing protocol as well. If it comes to halt the watertightness is made visible - a built in "hydro-test".
When the reaction is complete and the watertightness established, solution S2 is pumped out. Otherwise the procedure has to be repeated, S1 and S2 flooded again, until the required allowance rate of the given standard is achieved.
After flushing, the sewer is returned to service.
The pipe´s structure is protected by the soil-grout- envelope from further deterioration.
Creating in an artificial sandstone
The excavated mock pipes you can see here, provide an insight view on the reacted soil - grout matrix which is chemically related to an artificially made sandstone.
The self-regulating flood grouting procedure has created the optimum size of grout part that was necessary to withstand the maximum hydrostatic pressure head - up to the street level.
The improved pipe support and the elimination of water migration will prolong the service life of the pipes and manholes without reducing their inner diameter.
- Its water tightness is similar to homogeneous clay
- its mechanical strength is comparable with a weak concrete.
- The adhesion strength to the exterior pipe-walls varies depending on their material, whether being concrete, clay or PVC.
The grout matrix can encapsulate toxic materials on spot, like heavy metals or organic contaminants. This capability is called vitrification.
The reacted and neutralized Sanipor conglomerate is chemically resistant against:
- acids and bases between pH 1 to pH 10,
- against salt water and
- all kind of organic solvents and oil derivatives.
Along coastal lines and below industrial plants these capabilities are very important.
Sanipors design life is 50+ years, as long as the matrix is mechanically not disturbed or destroyed.
SANIPOR is an alternative to CIPP!
Flood Grouting is the better option in all cases where infiltration has to be stopped and the service life of a network of sewer collection systems extended effectively.
Only the minority of pipes (measured by length) are fractured and not self-supporting anymore. These require replacement and new bedding to regain stability.
Merely calibrated CIPPs of excellent quality (material and installation) may claim to represent a structural rehabilitation of broken pipes.
In the recent years the quality and durability of CIPP were tested with new methods. Nationwide, the majority of the examined CIPPs showed leaks and defects to a previously unimagined extent. Now the question emerges how to stop and avoid such gigantic failures and waste of money in the future. Stringent quality controls and alternative technologies should be introduced to the sewer rehabilitation market.
