Pyrite removal /
contaminated backfill
Symptoms and causes
Cracking or fractured garage and basement foundations walls, bulging
floors and whitish particles often indicate a pyrite problem. Lab tests
can show if any (and how much) pyrite-bearing rock is actually present.
If pyrite is present in rock that is used as fill beneath a concrete floor
or even occasionally in the concrete of the foundation itself, it will
oxidize on contact with moisture and oxygen. This oxidation generates
sulphuric acid, a substance that causes rock to burst and fill to swell.
The process of expansion places enormous pressure on overlying concrete
and will eventually damage it.
The same pyrite removal technique is also employed to remove fill contaminated
with such substances as heating oil.
The solution
Any existing damaged concrete must be crushed in such and the stone removed
from the contaminated fill.
Bisson Expert uses miniature excavation equipment to maximize the effectiveness
of our operations and to ensure total safety.
New fill using quality-controlled stones is spread and compacted and
then a new floor is poured. |
