| AAC - Autoclaved Aerated Concrete |
(Concrete Engineering) Exceptionally lightweight precast concrete with high thermal qualities and fire resistence. Suitable for cutting with ordinary hand tools. Mix design is composed of portland cement, sand or siliceous material, lime, gypsum, finely powdered aluminum, and water. Initial mix is a combination of portland cement, sand, lime and gypsum to produce a slurry. Finely powdered aluminum mixed into a paste is added prior to placement into large, rail-like forms. The finely powdered aluminum reacts with the alkaline components of the cement and lime to produce hydrogen gas, which increases the volume approximately five times producing a uniformly, dispersed cellular structure. Units are cut to required shape. Units are placed in an autoclave, an enclosed pressurized chamber, and steam cured at 3500 F. Approximately 80% of the ultimate volume consists of air voids. |
| Cellular Concrete |
(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. |
| Ottawa Sand |
(Concrete Engineering) A sand used as a standard in testing hydraulic cements by means of mortar test specimens. Sand is produced by processing silica rock particles obtained by hydraulic mining of the orthoquartzite situated in open-pit deposits near Ottawa, Illinois; naturally rounded grains of nearly pure quartz. |
| Preplaced Concrete |
(Concrete Engineering) Concrete manufactured by placing clean, graded coarse aggregate in a form and later injecting a portland cement-sand grout under pressure, to fill the voids. |
| Rebound |
(Concrete Engineering) Wet shotcrete or sand and cement which bounces away from a surface again at which pneumatically applied mortar is being projected. |
| Sacking |
(Concrete Engineering) Removing or alleviating defects on a concrete surface by applying a mixture of sand and cement to the moistened surface and rubbing with a coarse material such as burlap. |
| Sand (ASTM C125) |
(Concrete Engineering) That portion of an aggregate passing the No. 4 (4.76 mm) sieve and predominantly retained on the No. 200 (74 micron) sieve. |
| belt sander |
เครื่องขัด ประกอบด้วยกระดาษ ทราย สายพาน มอเตอร์ไฟฟ้า
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| sand paper |
กระดาษทราย |
| sand stone |
หินทราย หินที่เกิดขึ้นด้วยเมล็ดทรายจับเกาะกันเป็นก้อน |
