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A slab of pykrete Pykrete is made of 14% sawdust and 86% water by mass.. Pykrete (/ ˈ p aɪ k r iː t /, PIE-creet) [1] is a frozen ice composite, [2] originally made of approximately 14% sawdust or some other form of wood pulp (such as paper) and 86% ice by weight (6 to 1 by weight).
Lunarcrete, also known as "mooncrete", an idea first proposed by Larry A. Beyer of the University of Pittsburgh in 1985, is a hypothetical construction aggregate, similar to concrete, formed from lunar regolith, that would reduce the construction costs of building on the Moon. [3]
The variable density is normally described in kg per m 3, where regular concrete is 2400 kg/m 3. Variable density can be as low as 300 kg/m 3, [18] although at this density it would have no structural integrity at all and would function as a filler or insulation use only.
Hemp concrete has a low thermal conductivity, ranging from 0.06 to 0.6 W m −1 K −1, [24] [15] [25] a total porosity of 68–80% [24] [26] and a density of 200 kg /m 3 to 960 kg/m 3. [ 15 ] [ 27 ] Hemp concrete is also an aerated material with high water vapour permeability and its total porosity very close to open porosity allowing it to ...
After mixing, the cement hydrates and eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term "concrete". For a concrete construction of any size, as concrete has a rather low tensile strength, it is generally strengthened using steel rods or bars (known as rebars).
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
Instead, 200 kg blocks were cut out with a chainsaw, carried away on a sled, and flown by helicopter down to the town centre. [4] There they were melted together to make a block of ice weighing 3,050 kg. The block was placed in a specially constructed iron container, which was insulated with wood and glass wool. [6]
A wet mix concrete plant combines some or all of the above ingredients (including water) at a central location into a concrete mixer - that is, the concrete is mixed at a single point, and then simply agitated on the way to the jobsite to prevent setting (using agitators or ready mix trucks) or hauled to the jobsite in an open-bodied dump truck ...