| Portland Cement (ASTM C 150) | (Concrete Engineering) The product obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates. |
| Portland-Pozzolan Cement (ASTM C 595) | (Concrete Engineering) The product obtained by intimately intergrinding a mixture of portland-cement clinker and pozzolan, or an intimate and uniform blend of portland cement and fine pozzolan. |
| 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. |
| Precast | (Concrete Engineering) A concrete unit, structure or member that is cast and cured in an area other than its final position or place. |
| 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. |
| 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. |
| 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. |
| 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. |