| Screen (or Sieve) | (Concrete Engineering) A metallic sheet or plate, woven wire cloth, or similar device, with regularly spaced openings of uniform size, mounted in a suitable frame or holder for use in separating material according to size. |
| Slip Form | (Concrete Engineering) A form which is raised or pulled as concrete is placed; may move vertically to form wails, stacks, bins or silos, usually of uniform cross section from bottom to top; or a generally horizontal direction to lay concrete evenly for highways, on slopes and inverts of canals, tunnels, and siphons. |
| Slump Cone | (Concrete Engineering) A metal mold in the form of a truncated cone with a top diameter of 4”, a bottom diameter of 8”, and a height of 12”, used to fabricate the specimen for a slump test. |
| Temperature Rise | (Concrete Engineering) The increase of concrete temperature caused by heat of hydration and heat from other sources. |
| Unit Water Content | (Concrete Engineering) The quantity of water per unit volume of freshly mixed concrete, often expressed as gallons or pounds per cubic yard. This is the quantity of water on which the water cement ratio is based, and does not include water absorbed by the aggregate |
| Vapor Pressure | (Concrete Engineering) The pressure exerted by a vapor that is calculated based upon relative humidity and temperature. The higher the humidity and higher temperature, in degrees Fahrenheit, the greater the vapor pressure exerted. |
| Vibration | (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. |
| Vicat Apparatus | (Concrete Engineering) A penetration device used to determine the setting characteristics of hydraulic cements. |
| Wagner Fineness | (Concrete Engineering) The fineness of materials such as portland cement expressed as total surface area in centimeters per gram as determined by the Wagner turbidimeter apparatus and procedure. |
| Water-Cement Ratio | (Concrete Engineering) The ratio of the amount of water, exclusive of that absorbed by the aggregates, to the amount of cement in a concrete mix. Typically expressed as percentage of water, by weight in pounds, to the total weight of portland cement, fly ash, and any other cementitious material, per cubic yard, exclusive of any aggregates. |