Ad
related to: quantity calculation for m20 concrete
Search results
Results from the WOW.Com Content Network
A percentage is typically added to neat volume to estimate loose (i.e. uncompacted) volumes for procurement purposes. With concrete work, neat volume is calculated assuming there is no bowing in the formwork , or, for cast-in-place concrete, that the surfaces in contact with the concrete have no voids or imperfections that would require a ...
A w/c ratio higher than 0.60 is not acceptable as fresh concrete becomes "soup" [2] and leads to a higher porosity and to very poor quality hardened concrete as publicly stated by Prof. Gustave Magnel (1889-1955, Ghent University, Belgium) during an official address to American building contractors at the occasion of one of his visits in the ...
The test is carried out using a metal mould in the shape of a conical frustum known as a slump cone or Abrams cone, that is open at both ends and has attached handles.The tool typically has an internal diameter of 100 millimetres (3.9 in) at the top and of 200 millimetres (7.9 in) at the bottom with a height of 305 millimetres (12.0 in).The cone is placed on a hard non-absorbent surface.
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]
With BIM quantity take-off can be conducted almost automatically given that the type of materials, their quantity and price is included in the model. [2] It is known that construction projects often run overtime and over budget and one of the reasons is lack of accuracy in quantity takeoff and estimates.
The phase composition of a particular cement can be quantified through a complex set of calculation known as the Bogue formula. To avoid the flash setting of concrete, due to the very fast hydration of the tricalcium aluminate (C 3 A), 2–5 wt. % calcium sulfate is interground with the cement clinker to prepare the cement powder.
It is the same concept as volume percent (vol%) except that the latter is expressed with a denominator of 100, e.g., 18%. The volume fraction coincides with the volume concentration in ideal solutions where the volumes of the constituents are additive (the volume of the solution is equal to the sum of the volumes of its ingredients).
Mass concrete is defined by American Concrete Institute Committee 207 as "any volume of concrete with dimensions large enough to require that measures be taken to cope with the generation of heat from the hydration of cement and attendant volume change to minimize cracking."
Ad
related to: quantity calculation for m20 concrete