During drilling, slurry can accumulate or adhere to the inner and outer casings.

You need to blow that away with water and air.

In particular, gravel and soft rock come up without much trouble, but

Cohesive soils, silt, and sandy soils mixed with silt tend to adhere to the inner and outer casings.

Fill the casing with water and rotate the inner liner to remove any caked-on residue.

After that, blow it away with air and water.

If the water is extremely viscous, you'll need to continue this process until the water runs clear.

 

The reason why this is necessary is that,

I'll be picking up the inner layer first, so I'm not worried about it, but,

If there are a lot of stains on your outerwear,When inserting an anchor,

There is a risk that slime may adhere to the anchor mounting area.

Even if grout is applied over it, the bond between the prestressed steel strands and the grout remains intact, and

There may be insufficient friction.

As a result, there is a possibility that it could come loose.

 

We need to reduce that possibility as much as possible.