| Pining | (Concrete Engineering) Development of relatively small cavities in a concrete surface, due to phenomena such as cavitation or corrosion. |
| Plane of Weakness | (Concrete Engineering) The plane along which a structure under stress will tend to fracture; may exist because of the nature of the structure and its loading, by accident, or by design. |
| Plastic Consistency | (Concrete Engineering) Condition in which concrete, mortar, or cement paste will sustain deformation continuously in any direction without rupture. |
| Portland Cement (ASTM C 150) | (Concrete Engineering) The product obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates. |
| Pozzolan (ASTM C 618) | (Concrete Engineering) A siliceous, or siliceous and aluminous material, which in itself possesses little or no cementitious value but will, in a finely divided form, such as a powder or liquid and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form permanent, insoluble compounds possessing cementitious properties. |
| Preplaced Concrete | (Concrete Engineering) Concrete manufactured by placing clean, graded coarse aggregate in a form and later injecting a portland cement-sand grout under pressure, to fill the voids. |
| Rebound | (Concrete Engineering) Wet shotcrete or sand and cement which bounces away from a surface again at which pneumatically applied mortar is being projected. |
| 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. |
| 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. |