Use-case - |
(Software Engineering) a written description that defines a very specific interaction between a user and a system, often (but not always) written in the form of a usage scenario |
User-story - |
(Software Engineering) a usage scenario that is used as part of Extreme programming |
Carbonation |
(Concrete Engineering) 1) Reaction between the products of portland cement (soluble calcium hydroxides), water and carbon dioxide to produce insoluble calcium carbonate (efflorescence). 2) Soft white, chalky surface dusting of freshly placed, unhardened concrete caused by carbon dioxide from unvented heaters or gasoline powered equipment in an enclosed space. 3) Carbonated, dense, impermeable to absorption, top layer of the surface of concrete caused by surface reaction to carbon dioxide. This carbonated layer becomes denser and deeper over a period of time. 4) Reaction with carbon dioxide which produces a slight shrinkage in concrete. Improves chemical stability. Concrete masonry units during manufacturing may be deliberately exposed to carbon dioxide after reaching 80% strength to induce carbonation shrinkage to make the units more dimensionally stable. Future drying shrinkage is reduced by as much as 30%. |
Entrained Air (See air entrainment) |
(Concrete Engineering) Microscopic air bubbles intentionally incorporated in mortar or concrete, to improve workability and durability (usually imparting a higher degree of resistance to freezing and thawing). |
Gillmore Needle |
(Concrete Engineering) A device used in determining time of setting of hydraulic cement, described in ASTM 0 266. Gradation The sizing of granular materials; for concrete materials, usually expressed in terms of cumulative percentages larger or smaller than each of a series of sieve openings or the percentages between certain ranges of sieve openings. |
Saponification |
(Concrete Engineering) The deposit of a gray scum or gray dust on the inside surface of a subgrade wall or floor; as the result of moisture moving through the concrete and washing certain chemicals from the concrete mass. |
Screen (or Sieve) |
(Concrete Engineering) A metallic sheet or plate, woven wire cloth, or similar device, with regularly spaced openings of uniform size, mounted in a suitable frame or holder for use in separating material according to size. |
Vibration |
(Concrete Engineering) Energetic agitation of concrete to assist in its consolidation, produced by mechanical oscillating devices at moderately high frequencies. (A.) External vibration employs a device attached to the forms and is particularly applicable to the manufacture of precast items and for the vibration of tunnel lining forms. (B.) Internal vibration employs an element which can be inserted into the concrete; and is more generally used for cast-in-place construction. |
American screw gauge |
ที่วัดเส้นผ่านศูนย์กลางของสกรูที่ใช้กับงานไม้และงานเครื่องจักรกลตามมาตราฐานอเมริกัน |
button head screw |
ตะปูหัวกลมมีรอยผ่ากลาง
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