Efficient Sewer Rehabilitation - STAUB & CO.

Our Silago products, which have general technical approval no. Z-42.3-437 of the German Center of Competence for Construction, silicically seal defective sewers and pipes. This protects the groundwater and prevents extraneous water. The two-component flooding process is the first choice for inaccessible, geometrically complex and even non-inspectable sewers and pipes.

Silago SL1
Silago SL1 is a specially formulated aqueous silicate solution with high viscosity. It penetrates into leaks or through them into the soil by hydrostatic pressure and saturates the capillaries of the bedding.

Silago SL2
With Silago SL2, the pH value shifts into the weakly acidic range. This permanently fills the previously dissolved silicate, forming a waterproof sandstone packing with the bedding.

Both components are absolutely non-toxic. For Silago SL2, only substances are used that are also known as food additives. Soil ecology studies by the Gelsenkirchen Hygiene Institute have shown that the two individual components degrade excellently in the soil.

This is how the sealing of sewers and pipes with Silago works

When pipes and sewers are sealed with a flooding method, the result is on the outside of the pipe. Therefore, camera examinations cannot make visible whether the defective area has been sealed. Nevertheless, so that you can see how our Silago products work, we show you in a model how the two components react with each other. We presented the model at the 7th Sewer Cocktail of the GSTT (German society for Trenchless Technology e. V.) in Schwerte in 2010.

Experimental set-up to demonstrate the use and effect of the two-component Silago injection solutions

Our experimental setup

The bedding of a wastewater pipe is simulated in a Plexiglas pipe filled with small stones. As on a real construction site, the two components Silago SL1 and Silago SL2 are filled into the pipe in several cycles. The bedding (small stones) is silicified and the previously extremely permeable material in the pipe is sealed. After a few minutes, the liquid "stands" above the pebbles with the packing - the Plexiglas pipe is sealed.

Step by step

How easy it is to apply Silago

In this step-by-step guide, we show you how to rehabilitate an underground sewer pipe and manhole in a residential area in one operation using Silago.

With the Silago system, pipes, pipe joints and manholes are rehabilitated in a postural manner.
Sewers and pipes in the nominal size range DN 50 to DN 500 made of all common materials, such as

concrete,
vitrified clay,
cast iron
or even plastic,

can be rehabilitated.

For the rehabilitation works on the sewer you will need

1 vehicle with the two IBCs for the Silago SL1 and Silago SL2 components.
1 peristaltic pump for filling and emptying the sewer to be rehabilitated.
1 high pressure flushing device with various nozzles etc.
1 camera for sewer TV inspection
Shut-off elements in the form of shut-off bladders, if possible with a 2"-passage
Analysis equipment for quality assurance of Silago SL1 and Silago SL2 solutions
Other auxiliary equipment, e.g. pumps for securing the receiving flow

Step 1

Before you start

Calculate the volume of the entire rehabilitation section. Existing plans and inspection results can serve you as a basis. The best way to estimate the expected loss quantities of the injection medium is to determine the leakage rate or perform a water loss test.

Step 2

Cleaning and inspection of the pipe system.

Before the damaged section is rehabilitated, the sewer must be sufficiently cleaned. It may be necessary to flush the sewer again with high pressure.

Visually inspect the pipe system. Make sure that there are no broken shards or other damage that could endanger the statics.

Step 3

Silago SL1

Fill the pipe system with Silago SL1 from the lowest pipe point. If the liquid loss is low, fill Silago SL1 up to 2 m above the highest pipe apex. While filling Silago SL1, the rehabilitation vehicle can be positioned anywhere within a 20 m radius in order to interfere as little as possible with other road users.

Silago SL1 is extracted after 45 minutes at the latest.

Caution: In the case of larger loss quantities, Silago SL1 is already aspirated after a few minutes.
How far the liquid level drops can be determined and recorded by measuring the height in the chamber. Alternatively, a flow-through bladder with sight hose can be used.
Losses are replenished in accordance with the provisions of DIN EN 1610 on how to proceed in the event of a pressure drop of 0.01 bar.

The section to be rehabilitated must be flushed with water at low pressure after each filling. This prevents the channel walls from being wetted with Silago SL1. Hard-to-reach branches of the system are cleaned via the respective feeds by surge flushing.

Step 4

Silago SL2

Then fill the Silago SL2 component also up to 2 m above the highest pipe crown. Silago SL2 also remains in the rehabilitation section for approx. 45 minutes.

Silago SL2 changes the pH value. Thus, the previously dissolved silicate fills leaking areas and, together with the bedding, forms a waterproof sandstone packing.

The pipeline section is successfully rehabilitated when the liquid level does not sink any further. Silago SL2 is pumped out and the sewer is finally flushed again.

Step 5

Completion of the work

If the liquid level continues to drop after an exposure time of approx. 45 minutes, repeat the steps described above until the area to be remediated is tight.

All results and observations during sanitation are recorded in the sanitation protocol.

Larger loss quantities?

If the loss quantity of Silago SL1 exceeds 30% of the enclosure volume, this indicates major leakage. We will be happy to advise you on the further possibilities of trenchless sewer rehabilitation!