| Overvibration | (Concrete Engineering) Excessive vibration of freshly mixed concrete during placement-causing segregation. |
| Plastic | (Concrete Engineering) A condition of freshly mixed concrete. mortar or cement -paste indicating that it is workable and readily re-moldable, is cohesive, and has an ample content of fines and cement but is not over wet. |
| Plasticity | (Concrete Engineering) Property of freshly mixed concrete, cement paste or mortar which determines its ease of molding or resistance to deformation. |
| Rebound | (Concrete Engineering) Wet shotcrete or sand and cement which bounces away from a surface again at which pneumatically applied mortar is being projected. |
| Retardation | (Concrete Engineering) Delaying the hardening or strength gain of fresh concrete, mortar or grout. |
| Saponification | (Concrete Engineering) The deposit of a gray scum or gray dust on the inside surface of a subgrade wall or floor; as the result of moisture moving through the concrete and washing certain chemicals from the concrete mass. |
| 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. |
| Spall | (Concrete Engineering) A fragment, usually of flaky shape, detached from a larger mass by pressure, expansion from within the larger mass, a blow, or by the action of weather. |
| 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 |
| 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. |