| Work flow - | (Software Engineering) the sequence of tasks that are required to accomplish some activity or action; often (but not always) used in conjunction with software process models |
| Work product - | (Software Engineering) any cohesive and persistent information that is produced as a consequence of one or more software engineering actions of tasks |
| 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. |
| Adiabatic Curing | (Concrete Engineering) The maintenance of ambient conditions during the setting and hardening of concrete so that heat is neither lost nor gained from the surroundings of the concrete. |
| Adsorption Water | (Concrete Engineering) Water held on surfaces in a material by either physical and/or chemical forces. |
| Air Entraining Agent | (Concrete Engineering) An addition for hydraulic cement, or an admixture for concrete or mortar which entrains air in the form of minute bubbles in the concrete or mortar during mixing. |
| Alkali-Aggregate Reaction | (Concrete Engineering) Older terminology for Alkali-Silica Reactivity (ASR). |
| ASR - Alkali-Silica Reactivity | (Concrete Engineering) The reaction of aggregates, which contain some form of silica or carbonates with sodium oxides or potassium oxides in cement, particularly in warm, moist climates or environments, causing expansion, cracking or popouts in concrete. |
| Barrel (of cement) | (Concrete Engineering) A unit of weight for cement: 376 Ibs net, equivalent to 4 US bags of portland cement. The designation presently used is tons of cement. |
| Blast Furnace Slag | (Concrete Engineering) A non-metallic waste product developed in the manufacture of pig iron, consisting basically of a mixture of lime, silica and alumina, the same oxides that make up portland cement, but not in the same proportions or forms. It is used both in the manufacture of portland blast furnace slag cement and as an aggregate for lightweight concrete. |