To help site visitors, industrial distributors, and contractors understand or clarify many terms used in the concrete and paving industry, dee Concrete Accessories has included this one-of-a-kind glossary. The glossary is organized as an alpha listing to assist you to quickly find the term you are looking for.
Click a letter below to take you to the corresponding page in the glossary:
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Abrams' law
The rule stating that with given materials, curing, and testing conditions, concrete strength is inversely related to the ratio of water to cement. Low water-to-cement ratios produce higher strengths.
Abrasive aggregate
The aggregate used to increase the abrasiveness of the surface of a concrete slab.
Absolute volume
In concrete, the actual volume occupied by the different ingredients determined by dividing the weight of each ingredient pounds, by its specific gravity, times the weight of one cubic foot of water in pounds.
Example: Absolute Volume of one sack of cement equals: 94 ÷ (3.15 x 62.4) = 0.478 cubic feet.
Absorption
The process by which water is absorbed. The amount of water absorbed under specific conditions, usually expressed as percentage of the dry weight of the material.
Absorption loss
Water losses that occur until the aggregate in a concrete mix is saturated. See aggregate.
Acceleration
The speeding up of the setting or hardening process of concrete by using an additive in the mix. The process of acceleration allows forms to be stripped sooner or floors finished earlier. See accelerators.
Accelerators
Material additives used to accelerate, or reduce, the setting time of concrete causing it to harden faster. Accelerators often include calcium chloride, or aluminum sulfate or other acidic materials. See set retarders.
Accessories
The items used to assemble scaffolding, shoring, and forms, other than the walers, frames, and the forms themselves in the placing of concrete. See curb and gutter forms, flatwork forms, filler forms, flexible forms, straight forms, and walers.
Adiabatic curing
The maintenance of ambient conditions during the setting and hardening of concrete so that heat is neither lost nor gained from the surroundings of the concrete.
Adjustable Hanger
A forming accessory, a metal strip, used to suspend or support metal forms or metal form attachments when traditional methods of anchoring forms or form attachments cannot be used due to trenching or prior concrete placement. See hanger.
Admixture
A material, other than aggregate, cement, or water, added in small quantities to the mix in order to produce some desired modifications, either to the physical or chemical properties of the mix or of the hardened product. The most common admixtures affect plasticity, air entrainment, and curing time. These admixtures are often referred to as plasticizers, superplasticizers, accelerators, dispersants, and water-reducing agents.
Advanced Cement-Based Materials (ACBM)
A center at Northwestern University established by the National Science Foundation to create new cement–based materials with improved properties.
Aerated concrete
Concrete formed using gas-forming admixtures such as powdered zinc or aluminum combined with calcium hydroxide or hydrogen peroxide that form hydrogen or oxygen bubbles in the cement mix.
Aggregate
A mixture of sand, rock, crushed stone, expanded materials, or particles that typically compose 75% of concrete by volume improve the formation and flow of cement paste and improve the concrete's structural performance. See concrete.
Aggregate, exposed or exposed aggregate
A concrete surface with the aggregate exposed, formed by applying a retarder to the surface before the concrete has set, and subsequently removing the cement paste to the desired depth. See aggregate.
Aggregate testing
Any of a number of tests performed to determine the physical and chemical characteristics of an aggregate. Common tests are for abrasion, absorption, specific gravity, and soundness. See aggregate.
Agitating speed
The rate at which a concrete or mortar mixer rotates the drum or blades in order to agitate mixed materials to prevent segregation or setting. See concrete mixture, mixing speed, segregation, and set.
Agitation
The rotation of, or moving of blades through, a drum containing concrete or mortar to prevent segregation or setting of mixture. See concrete and segregation.
Agitator
A mechanical device used to maintain plasticity and to prevent segregation, particularly in concrete and mortar. See concrete and segregation.
Agitator truck
Vehicle designed to take pre- or ready-mixed concrete and deliver it ready to be used at a construction site. The truck bed contains a large barrel or drum that is used to continuously roll or agitate the concrete mixture keeping it from solidifying before use. See ready-mixed concrete.
Air content
The amount of entrained or entrapped air in concrete or mortar, exclusive of pore space in aggregate particles, usually expressed as a percentage of total volume of concrete or mortar.
Air-entrained agent
An additive to hydraulic cement or an admixture for concrete or mortar that causes air to be incorporated in the form of minute bubbles on the concrete or mortar during mixing, usually to increase its workability and frost resistance. See hydraulic cement.
Air-entrained concrete
A Portland cement with an admixture that causes a controlled quantity of stable, very small air bubbles to form in the concrete during mixing. See non-air-entrained concrete.
Air-permeability test
A procedure for determining the fineness of powdered material such as cement.
Air content
The volume of air present in a concrete or mortar mix, expressed as a percentage of the total volume. A controlled air content prevents concrete from cracking during the freeze/thaw cycle.
Air meter
A device for measuring the air content of a concrete or mortar mix. See air content and mix.
Air slacking
The absorption of moisture and carbon dioxide from the air by lime or cement.
Alkali-Aggregate Reaction
Older terminology for Alkali-Silica Reactivity (ASR).
Alkali-Silica Reactivity (ASR)
The reaction of aggregates, which contain some form of silica or carbonates with sodium oxides or potassium oxides in cement, particularly in warm, moist climates or environments, causing expansion, cracking or popouts in concrete.
American Association of State Highway and Transportation Officials (AASHTO)
An organization that represents highway and transportation departments in the 50 states, the District of Columbia and Puerto Rico.
American Concrete Institute (ACI)
An international organization dedicated to providing knowledge and information for the best uses of concrete.
American National Standards Institute (ANSI)
An organization that represents the United States in the International Organization for Standardization (ISO).
American Standard of Testing Materials (ASTM)
An organization that has developed a variety of methods for testing the strength of cement and other building materials to ensure it complies with needed strength requirements.
Anchor bolts
Bolts to secure a wooden sill plate to concrete, masonry floor, or wall.
Angle float (angle trowel)
A trowel with two surfaces meeting at right angles. An angle float is used for finishing plaster or concrete in an inside corner. See float and trowel.
Apron
A slab of concrete extending beyond the entrance to a building, particularly at an entrance for vehicular traffic. At an airport, the pavement adjacent to hangars and appurtenant buildings. See paving forms.
Architectural concrete
Structural or nonstructural concrete that will be permanently exposed to view and therefore requires special attention to uniformity of materials, forming, placing, and finishing. This type of concrete is frequently cast in a mold and has a pattern on the surface. See fair face concrete.
Arrissing tool
A special float used to round the edges of freshly placed concrete. See concrete and float.
Asphalt
A black petroleum residue, which can be anywhere from solid to semisolid at room temperature. When heated to the temperature of boiling water, it becomes able to be poured. It is used in roofing materials, surfacing roads, in lining the walls of water-retaining structures such as reservoirs and swimming pools, and in the manufacture of floor tiles. Asphalt should not be confused with tar, a similar looking substance made from coal or wood and incompatible with petroleum derivates.
Asphalt cement
Asphalt that has been refined to meet the specifications for use in paving and other special uses. It is classified by penetration.
Asphalt expansion joint
Premolded felt or fiberboard impregnated with asphalt and used extensively as an expansion joint for cast-in-place concrete.
Asphalt leveling course
A course of asphaltic concrete pavement of varying thickness spread on an existing pavement to compensate for irregularities prior to placing the next course.
Autoclave
A chamber in which an environment of steam and high pressure is produced. Used in curing of concrete products and in the testing of hydraulic cement for soundness.
Autoclaved Aerated Concrete (AAC)
Autoclaved Aerated Concrete (AAC) is a mixture of portland cement, quicklime, sand, water and aluminum powder. The chemical interaction of these “aerated" natural materials creates a porous, closed cell masonry material with a density of approximately forty-five (45) pounds per cubic foot, roughly one-third the weight of stone concrete. A high temperature, high-pressure steam cure in an autoclave speeds additional chemical reactions, which allow the AAC to reach full strength in less than twenty-four (24) hours. AAC is easy to use on a job site and provides excellent sound proofing and fire protection.
Auxiliary reinforcement
In a pre-stressed concrete member, refers to all reinforcing steel other than the pre-stressing steel. See pre-stressed concrete.
