"Fixing Alkali Problems"
Time-Tested Performance
Alkali is never pure and rarely stable. It is
made up of a combination of elements and almost always reacts
with other elements.
We start with hydrogen, then lithium, sodium,
potassium, rubidium, cesium and francium. Francium is radioactive
with a half-life of only twenty minutes. The other five are very
active alkali metals. Each element has electrons and molecules,
which are always eager to take part in chemical reactions with
other elements. The two most important alkali metals are sodium
and potassium. We find a hint of them in potassium carbonate and
sodium carbonate. Sodium makes up 2.6% of the earth's crust and
potassium makes up 2.5%, yet we never see them. They are always
found in combinations with other elements. Neither of them could
remain pure in air or moisture.
The increased use of concrete subfloors in direct
contact with the ground makes more important than ever, the complete
understanding of moisture and alkali inherent in these subfloors
and their effects on paints and floor coverings. Well known as
the "alkali problem", this condition is primarily a
problem of moisture. Alkali is present in every concrete slab
and is more detrimental with moisture. On adequately ventilated,
suspended concrete subfloor moisture is not present in troublesome
quantities.
Where the slab is in direct contact with the
ground or a poorly ventilated air space, moisture is brought up
through the slab by capillary action. It dissolves the alkaline
slats in the concrete and appears at the surface as a destructive
alkaline solution causing spalling and efflorescence.
Although moisture and alkali conditions may vary
greatly, there is always sufficient moisture in the ground to
come in contact with the alkali in concrete to present an "alkali
problem" on subfloors affected by ground moisture. It is
never safe to assume that a concrete slab will always by dry because
is has been dry; moisture content may be small. When paint or
floor coverings are applied, the moisture and alkali collects
under the coverings. This often results in coverings buckling,
warping, or separating from the concrete surface.
SealMaxx recommends SEAL-IT Concrete Sealant to
alleviate this problem. SealMaxx can seal and waterproof the concrete
to eliminate spalling and efflorescence, leaving clean pores to
which paint, mastics or adhesives for floor covering can effectively
secure a better bond. The destructive moisture attacking problems,
which causes deterioration to adhesives and paints will also be
eliminated.
Efflorescence becomes a problem when moisture
is introduced. Moisture transports efflorescence through the concrete,
thereby destroying concrete and the steel holding it together.
90% of the problem is moisture; SEAL-IT Concrete Sealant penetrates
into the concrete, reacts with the alkali and forms a hydrostatic
head, barring the migration of moisture.