| Architecture - | (Software Engineering) the overall structure of software components, the data and/or content that components manipulate, and the relationships between them |
| Aspect-oriented development - | (Software Engineering) a development approach that emphasizes "concerns" (also called "aspectual requirements" that incorporate features, functions and information content) that cut across multiple system functions |
| Automated estimation tools - | (Software Engineering) tools that help in estimating project cost or effort |
| Automatic code generation - | (Software Engineering) tools that generate source code from a representation of software that is not source code |
| 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. |
| Absolute Volume | (Concrete Engineering) The volume of an ingredient in its solid state, without voids between individual pieces or particles, in the case of fluids, the cubic content occupied. In concrete, the actual volume occupied by the different ingredients determined by dividing the weight of each ingredient pounds, by ifs specific gravity, times the weight of one cubic foot of water in pounds. Example: Absolute Volume of one sack of cement equals: 94 ๗ (3.15X62.4) = 0.478 cubic feet |
| Absorbed Moisture | (Concrete Engineering) Moisture which is mechanically held in a material. In aggregates, that water which is not available to become part of the mixing water is designated "absorbed" water. |
| 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 Content | (Concrete Engineering) The amount of entrained or entrapped air in concrete or mortar, exclusive of pore space in aggregate particles, usually expressed as a percentage of total volume of concrete or mortar. |