| Precast | (Concrete Engineering) A concrete unit, structure or member that is cast and cured in an area other than its final position or place. |
| Pretensioning | (Concrete Engineering) A method of prestressing reinforced concrete in which the steel is stressed before the concrete has hardened and restrained from gaining its unstressed position by bond to the concrete. |
| Pumping (of Pavements) | (Concrete Engineering) The ejection of a mixture of water and solid materials such as clay or silt along cracks, transverse or longitudinal joints, and along pavement edges caused by downward slab movement due to the passage of heavy loads, machinery or equipment over the pavement after free water has accumulated in or on the subbase, subgrade or basecourse. |
| Retempering | (Concrete Engineering) The addition of water and remixing of concrete which has started to stiffen: usually not allowed as it may affect the ultimate strength. |
| Revibration | (Concrete Engineering) Delayed vibration of concrete that has already been placed and consolidated. Most effective when done at the latest time a running vibrator will sink of its own weight into the concrete and make it plastic and workable again. |
| Rod (tamping) (ASTM C24l) | (Concrete Engineering) A round, straight steel rod, 5/8' in diameter and approximately 24' in length, having the tamping end rounded into a hemispherical tip, the diameter of which is 5/8'. |
| Sack | (Concrete Engineering) A quantity of cement: 94 Ibs. in the United States, 87.5 Ibs. in Canada, for portland or air entraining portland cement, or as indicated on the sack for other kinds of cement. |
| 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. |
| 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. |