Penetron® Feature: Penetron Admix Enhanced Shotcrete (PAES)

Tunnel waterproofing is often done by using shotcrete structures that lead the water from the rock into a subsurface draining system. The main problem with this solution is making the shotcrete waterproof. Water leakage is normally caused by cracks in the shotcrete, bad workmanship and porous shotcrete. We traditionally recommended to spray Penetron onto the shotcrete surface. While this is very efficient, it is also labor intensive and hence expensive... In recent years, a better solution was found; using Penetron Admix enhanced shotcrete!

Penetron Admix enhanced shotcrete (PAES) has been extensively tested by accredited concrete laboratories. The test results show that PAES reached the maximum result in the freeze/thaw test SS(EN)-137244 and reduced the depth of penetration of water under pressure Norm SS EN-12390-8 from 21mm for the control concrete to 7mm for PAES. The adhesion values of this shotcrete increases as well.

PAES was tested in 2008 at CONCREMAT in Brazil in accordance with the following standards;

Concrete aggregates – NBR 7211/05
Water penetration test according to NBR 10787/94
Electrical resistance – NBR 9204/85
Capillary Test– SAI 162/1
Water absorption, voids and specific gravity – NBR 9778/05

Two steel drums, with numerous drill holes to allow the water pressure to build up, were primed with a cement mortar for increased adhesion. PAES was applied to one drum and a control shotcrete without Penetron Admix to the other one.

The two drums where then cured for 5 days, sealed and filled with water, after which a water pressure of 2 bar was applied.
PAES

A visual evaluation showed that the PAES coated drum was around 70% dry, whereas the control shotcrete was completely soaked with water.