ผลการค้นหา

Bars

แปลว่า(english) A relatively long straight, rigid piece pf metal; long steel products rolled from billets into such shapes as squares,rectangles, rounds,angles,channels,hexagons,and tees. In steel, “merchant bars” include rounds,flats,angles,squares,and channels that are used by fabricators to manufacture a wide variety of products such as furniture,stair railings and farm equipment. Concrete reinforcing bar (rebar) is used to strengthen concrete in highways,bridges and buildings.

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%.