ผลการค้นหา

Centroid:

แปลว่า(english) Similar to the concept of center of gravity, except that it applies to a two dimensional shape rather than an object. For a given shape, the centroid location corresponds to the center of gravity for a thin flat plate of that shape, made from a homogeneous material.

Bismuth

แปลว่า(english) Chemical symbol Bi. A soft, course cystalline heavy metal with a silvery white color and pinkish tinge; usually produced as a by-product of copper,leaad and other metals. Has a thermal conductivity lower than all other metals except mercury. Used as alloying agent but leading use is in pharmaceuticals.

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Gillmore Needle

แปลว่า(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.

Cellular Concrete

แปลว่า(Concrete Engineering) A lightweight product consisting of portland cement, cement-pozzolan, cement sand, lime-pozzolan, or lime-sand pastes, or pastes containing blends of these ingredients and having a homogenous void or cell structure, attained with gas forming chemicals or foaming agents. For cellular concretes, containing binder ingredients other than or in addition to portland cement, autoclave curing is usually employed.

Support:

แปลว่า(english) A support contributes to keeping a structure in place by restraining one or more degrees of freedom. In a structural model, supports represent boundary entities which are not included in the model itself, e.g., foundations, abutments, or the earth itself. For each restrained translation degree of freedom at a support, there is a corresponding reaction force; for each restrained rotation degree of freedom, there is a reaction moment.

Vibration

แปลว่า(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.

Brazing

แปลว่า(english) Joining metals by fusion of nonferrous alloys that have melting points above 800 F (425C), but lower than those of the metals being joined. May be accomplished by a torch. Filler metal is ordinarily in rod form in torch brazing; whereas in furnace and dip brazing the work material is first assembled and the filler metal may then be applied as wire, washers, clips, bands, or may be bonded, as in brazing sheet.

Aging 2

แปลว่า(english) A change in properties that occurs at ambient or moderately elevated temperatures after hot working or a heat treating operation (quench aging in ferrous alloys), or after a cold working operation (strain aging). The change in properties is often, but not always, due to a phase change (precipitation), but does not involve a change in chemical composition. In a metal or alloy, a change in properties that generally occurs slowly at room temperature and more rapidly at higher temperatures.

Water Vapor Pressure

แปลว่า(Concrete Engineering) The pressure exerted by water vapor. Air that contains higher amounts of water vapor exerts a higher vapor pressure than air which has a lower amount of has a higher water vapor pressure In concrete water vapor pressure is calculated by the difference between the vapor pressure of the concrete and the ambient relative humidity and temperature and in contact with the soil. that is calculated by; based upon relative humidity and temperature. The greater the difference between the water vapor and ambient humidity and temperature, in degrees Fahrenheit. the greater the water vapor pressure exerted.

Bainite

แปลว่า(english) A eutectoid transformation product of ferrite and a fine dispersion of carbide, generally formed at temperatures below 840 to 930 F (450 to 500 C): upper bainite is an aggregate containing parallel lath-shape units of ferrite, produces the so-called feathery appearance in optical microscopy, and is formed at temperatures above about 660 F (350 C); lower bainite consists of individual plate-shape units and is formed at temperatures below about 660 F (350 C). Also, a slender, needle-like (acicular) microstructure appearing in spring steel strip characterized by toughness and greater ductility than tempered Martensite. Bainite is a decomposition product of Austenite best developed at interrupted holding temperatures below those forming fine pearlite and above those giving Martensite.

Carbonation

แปลว่า(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%.