| Mixing Speed | (Concrete Engineering) Rate of mixer drum rotation or that of the paddles in a pan, open-top, or trough type mixer, when mixing a batch; expressed in revolutions per minute (rpm) or in peripheral] feet per minute of A point on the circumference at maximum diameter. |
| Particle-Size Distribution | (Concrete Engineering) Particle distribution of granular materials among various sizes; for concrete material normally designated as gradation. Usually expressed in terms of cumulative percentages smaller or larger than each of a series of sieve openings or percentages between certain ranges of sieve openings. |
| 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. |
| 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 |
| 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. |
| Vaporproof | (Concrete Engineering) A material that is totally immune to the passage of a gas under pressure. Any material that is truly vaporproof will inherently be waterproof. |
| 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. |
| Water Vapor Pressure | (Concrete Engineering) The pressure exerted by water vapor. Air that contains higher amounts of water vapor exerts a higher vapor pressure than air which has a lower amount of has a higher water vapor pressure In concrete water vapor pressure is calculated by the difference between the vapor pressure of the concrete and the ambient relative humidity and temperature and in contact with the soil. that is calculated by; based upon relative humidity and temperature. The greater the difference between the water vapor and ambient humidity and temperature, in degrees Fahrenheit. the greater the water vapor pressure exerted. |