TITLE:
Functional Acrylic Polymer as Corrosion Inhibitor of Carbon Steel in Autoclaved Air-Foamed Sodium Silicate-Activated Calcium Aluminate/Class F Fly Ash Cement
AUTHORS:
Toshifumi Sugama, Tatiana Pyatina
KEYWORDS:
Calcium Aluminate Foamed Cement; Thermal Shock Resistance; Corrosion Protection; Carbon Steel
JOURNAL NAME:
Engineering,
Vol.5 No.11,
November
6,
2013
ABSTRACT: The study focused on investigating the
effectiveness of functional acrylic polymer (AP) in improving the ability of
airfoamed sodium silicate-activated calcium
aluminate/Class F fly ash cement (slurry density of ￡1.3 g/cm3) to mitigate the corrosion of carbon steel (CS)
after exposure to hydrothermal environment at 200?C or 300?C.
Hydrothermally-initiated interactions between the AP and cement
generated the formation of Ca-, Al-, or Na-complexed carboxylate derivatives
that improved the AP’s hydrothermal stability. A porous microstructure
comprising numerous defect-free, evenly distributed, discrete voids formed in
the presence of this hydrothermally stable AP, resulting in the increase in
compresive strength of cement. The foamed cement
with advanced properties conferred by AP greatly protected the CS against brine-caused
corrosion. Four major factors governed this protection by AP-incorporated
foamed cements: 1) Reducing the extents of infiltration and transportation of
corrosive electrolytes through the cement layer deposited on the underlying
CS surface; 2) Inhibiting the cathodic reactions at the corrosion site of CS;
3) Extending the coverage of CS by the cement; and 4) Improving the adherence
of the cement to CS surface.