Literature Review on Building Envelope, Heating and ... - Beeshive.org

Frost-Resistant Concrete Mixture
Pathak (1996) noted that freezing fresh concrete greatly affects its strength. Concrete
exposure to a cold environment induces thermal cracking. Frozen concrete is strong, but
because the strength is due to ice cementing, the strength vanishes as the concrete thaws.
As a solution, he recommended using heating, thermal protection, and special frostresistant
concrete mixtures and mortars. Admixtures commonly used in cold regions
(such as air entraining agents, accelerators, plasticizers, and antifreeze) improve the
workability, curing properties, or freeze–thaw resistance. Calcium chloride is the most
commonly used accelerator, which provides rapid strength and reduces the time needed
for protection. Pathak described a hydraulic binder that is primarily binder slurry, which
is poured over the compacted aggregate in a special manner. The hydraulic binder was
used in the foundations of the Indian antarctic station. Pathak also recommended that
foundations should be placed as far as possible below the active layer of the permafrost
and should avoid drainage channels.
New Aluminum Alloys
Pathak (1996) noted that the properties of aluminum alloys in general are favourable for
cold climate applications. Aluminum’s mechanical properties improve slightly with
decreasing temperature. Aluminum has good corrosion resistance strength, good weldability,
and a low weight/strength ratio. Two aluminum alloys, RDE-32 and RDE-40,
were developed and were used in the construction of a 20 x 20 m (66 x 66 ft.) helipad at
Antarctica that was constructed of aluminum planks with an insulated underside.
Sandwich Composite Panels
These panels, made of plywood on both sides with core insulation between them, were
used in the construction of modular structures (living accommodation, kitchen, etc.) in
both Antarctica and the Indian Himalayas. At Antarctica, timber frame was used and the
panel thickness was 124 mm/4 7/8 in. (12 mm/1/2 in. thick marine plywood on each side
and 100 mm/4 in. core polyurethane foam insulation). Outdoor temperature was as low as
-45ºC (-49ºF), and the inside temperature was maintained in the range of 15ºC to 20ºC
(59ºF to 68ºF). Pathak noted that the floor needed additional insulation, because
temperatures varied from -4ºC (25ºF) at the floor to 15ºC (59ºF) at the ceiling. At the
Indian Himalayas site, aluminum portals were used and the panel thickness was 86 mm/3
3/8 in. (3 mm/1/8 in. of fire retardant grade fibre-reinforced polymer on both sides and 80
mm/3 1/8 in. phenolic core batt insulation).
Sealing Compound
Silicon gel-sealing compound worked well in joints between panels, columns, walls, etc.
at Antarctica and in the Indian Himalayas. But a better sealing compound is needed to
withstand blizzard conditions.
Fire Retardant Material
Gypsum board was found to be an effective fire retardant material in interior wall and
ceiling surfaces. For cladding, plastisol coated gypsum sheets were used.
PERD-079: Task 2 - <strong>Literature</strong> <strong>Review</strong> 56