A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

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- A -

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.

Accelerator An admixture which, when added to concrete, mortar, or grout, increases the rate of hydration of the hydraulic cement, shortens the time of set and increases the rate of hardening or strength development.

ACI  American Concrete Institute

Admixture A material other than water, aggregates, and Portland cement that is used as an ingredient of concrete, and is added to the batch immediately before or during the mixing operation.

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.

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.

ASTM - American Society for Testing and Materials

Auxiliary reinforcement  In a pre-stressed concrete member, refers to all reinforcing steel other than the pre-stressing steel.

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- B -

Barrel (of cement) A unit of weight for cement: 376 Ibs net, equivalent to 4 US bags of Portland cement.

BauBundles  A BauBundle is composed of tightly packed BauGrids® or BauLadders® that are interconnected by positioner wires. The BauBundles are shipped as compact bundles that are then quickly expanded so that the BauGrids® and BauLadders® are held by the position wires at their correct spacing.

BauGrid Welded Reinforcement Grid (WRG) System®  High Strength Welded Steel Reinforcement. Manufactured to ± 1/8" tolerance as grids (BauGrids®) and Ladder (BauLadders®) shapes. Used to reinforce ductile concrete and masonry shearwalls in the ladder shape (BauLadders®). Used to reinforce ductile concrete frames in the grid shape (BauGrids®). The dimensions of the cell openings in the grids and ladders vary depending upon the diameter of the longitudinal reinforcement bars.

BauGrids®  Grids of welded high strength (80 ksi) steel up to 5/8" in diameter. For ductile concrete frames the BauGrids® are closely spaced (3" o.c.) as one-piece ties in columns and one-piece stirrups in beams.

BauLadders®  A BauLadder® is a ladder of welded high strength (80 ksi) steel up to 1/8" in diameter. The BauLadders® are positioned horizontally to serve as boundary element reinforcement, shear reinforcement and minimum horizontal reinforcement in ductile concrete and masonry shear walls.

BauCage  The BauCage is composed of expanded BauBundles, sometimes incorporating a BirdCage®, through which longitudinal reinforcement up to 60' in length has been charged.

BauCage Assembly Fixture  The BauCage Assembly Fixture is a portable adjustable rack that holds birdcages and/or expanded BauBundles or individual BauGrids® or BauLadders®. Longitudinal reinforcement up to 60' in length is charged through the pre-positioned BauGrids® or BauLadders®.  By slightly rotating the rack holding the BauGrids® and BauLadders®, the longitudinal reinforcement is clinched by the BauCage so that only minimal wire tying is required.

BauCon  The BauCon is a standard threaded reinforcing bar coupler slightly modified to make it a viscoelastic damper. The copolymer filler can be in sheet form bonded inside the coupler or poured into the coupler. The BauCon, when connecting precast and poured-in place concrete members in seismic regions, reduces the demand on the concrete structure significantly during strong ground motion.

BirdCage®  The BirdCage® is a three dimensional pre-fabricated cage of BauGrids® which is a core of a ductile column joint, manufactured to very tight dimensional tolerances.

Bond Adhesion of concrete or mortar to reinforcement, or to other surfaces.  The adhesion of cement paste to aggregate.

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- C -

Cement, Portland (ASTM C150)  A powdery substance made by burning, at a high temperature, a mixture of clay and limestone producing lumps called “clinkers” which are ground into a fine powder consisting of hydraulic calcium silicates. 

Cementitious  Having cement-like, cementing, or bonding type properties.  Material or substance producing bonding properties or cement-like materials

Cold Joint A visible lineation which forms when the placement of concrete is delayed. The concrete in place hardens prior to the next placement of concrete against it.

Compression Forces acting inwardly on a body.

Compressive Strength The measured resistance of a concrete or mortar specimen to axial loading expressed as pounds per square inch {psi) of cross-sectional area. The maximum compressive stress which material, portland cement, concrete, or grout is capable of sustaining.

Concrete A composite material which consists essentially of a binding medium,  within which are embedded particles or fragments of a relative inert filler in Portland cement concrete, the binder is a mixture of Portland cement, possibly additional cementitious materials such as fly ash and water; the filler may be any of a wide variety of natural or artificial, fine and coarse aggregates; and in some instances, an admixture.

Construction Joint The contact between the placed concrete and concrete surfaces, against or upon which concrete is to be placed and to which new concrete is to adhere, that has become so rigid that the new concrete cannot be incorporated integrally by vibration with that previously placed. Unformed construction joints are horizontally placed or nearly so.  

Cure Method of maintaining sufficient internal humidity and proper temperature for freshly placed concrete to assure proper hydration of the cement, and proper hardening of the concrete

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- D -

Ductility Ductility is the physical property of being capable of sustaining large plastic deformations without fracture
Durability The ability of concrete to resist weathering action, chemical attack, and abrasion.
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- E -

Elasticity The ability of a material to return to its original shape after being stretched.


Entrained Air  Microscopic air bubbles intentionally incorporated in mortar or concrete, to improve workability and durability (usually imparting a higher degree of resistance to freezing and thawing).

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- F -

Flashing  A thin impervious material placed in mortar joints and through air spaces in masonry to prevent water penetration and/or provide water drainage.


Flexural Strength A property of a solid that indicates its ability to withstand bending.

Fly Ash The finely divided residue that results from the combustion of ground or powdered coal, transported from the firebox through the boiler by flue gases.

Forms Holders in which concrete is placed to harden.

Fracture A fracture is a break in a solid item that causes discontinuity without the substance actually separating into two or more pieces.
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- G -

GridCage™  The GridCage is composed of expanded BauBundles, sometimes incorporating a BirdCage®.  The difference between a GridCage and a BauCage is that the BauCage has had the longitudinal rebar charged through it, the GridCage has not.

Grout A fluid mixture of (1) cement, sand, and water or (2) cement and water: the hardened equivalent of such mixtures.

Gunite A term sometimes used to designate dry-mix shotcrete.

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- H -

Hydration Formation of a compound by the union of water with some other substance. In concrete it is the chemical reaction between water and the cement.  A concrete slab needs to completely hydrate prior to the application of paints, coatings, and flooring materials.

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- I -

Initial Set A degree of stiffening of the cement and water mixture. This is a degree less than final set and is generally stated as an empirical value, indicating the time in hours and minutes required for a cement paste to stiffen sufficiently to resist to an established degree the penetration of a weighted test needle. (Refer to ASTM C191 or C286 for weight and penetration data.)  

Initial stress In prestressed concrete, the stresses occurring in the prestressed members before any losses occur.

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- J -

Jacking Equipment In prestress concrete, the device used to stress the tendons.

Jacking Force The temporary force exerted by the jacking device which introduces tension into the tendons. 

Jacking Stress In prestress concrete, the maximum stress occurring in a tendon during stressing.

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- L -

Liquefaction The change of state to a liquid.  Term used instead of condensation in reference to substances, which are usually gaseous.
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- M -

Mixer Equipment used for mixing or blending the materials used in the manufacture of concrete, grout or mortar.

Mixing Speed 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.

Mixing Time For stationary mixers, mixing time is calculated in minutes from the completion of charging the mixer until the beginning of discharge; for truck mixer, time is calculated in total minutes at a specified mixing speed. the period during which materials used in a batch of concrete are combined by the mixer

Modulus of Elasticity A measure of the resistance of material to deformation. The ratio of normal stress corresponding strain for tensile or compressive stresses below the proportional limit of the material; elastic modulus is denoted by the symbol "2".

Monolithic A plain or reinforced mass of concrete cast as a single, one piece, integral structure.  

Mortar A mixture of cement, sand and water. When used in masonry construction, the mixture may contain masonry cement, or standard portland cement with lime or other ad-mixtures which may produce greater degrees of plasticity and/or durability.

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- N -

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- O -

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- P -

Pea Gravel Portion of concrete aggregate passing the 3/8' sieve and retained on a No.4 sieve.
Plastic deformation Plastic deformation is a non-reversible change in the shape of an object.

Plasticity Property of freshly mixed concrete, cement paste or mortar which determines its ease of molding or resistance to deformation.

Plasticizer A material that increases the workability or consistency of a concrete mixture, mortar or cement paste. 

Portland Cement (ASTM C 150) the product obtained by pulverizing clinker consisting essentially of hydraulic calcium silicates.  

Portland-Pozzolan Cement (ASTM C 595) 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.  

Post-tensioning A method of prestressing concrete in which the tendons are tensioned after the concrete has hardened.  

Pozzolan (ASTM C 618) 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 A concrete unit, structure or member that is cast and cured in an area other than its final position or place.

Prestressed Concrete  Concrete in which stresses have been introduced which are opposite in sense to those that the structural member will be expected to carry during its use.  

Pretensioning 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.

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- Q -

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- R -

Reinforced Concrete

A.       Concrete in which reinforcement, other than that provided for temperature changes for shrinkage, has been embedded in such a- manner that the two materials act together in resisting forces.

B.       Concrete in which steel bars have been placed to sustain the tensile stresses.

Revibration 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.

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- S -

Sack 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.


1.       Firmly placed grade strips or side forms which are set as  guides for a straight edge to bring the surface of concrete to the required elevation.

2.       To strike off concrete above the desired level.

Shotcrete Mortar or concrete conveyed through a hose and projected pneumatically at high velocity onto a surface; dry-mix shotcrete (gunite), and wet-mix shotcrete.

Slip Form A form which is raised or pulled as concrete is placed; may move vertically to form wails, stacks, bins or  silos, usually of uniform cross section from bottom to top; or a generally horizontal direction to lay concrete evenly for highways, on slopes and inverts of canals, tunnels,  and siphons.

Slump A measure of the consistency of plastic concrete relative to the amount it falls when a slump cone filled with concrete is lifted vertically.  The slump cone is then placed beside the specimen of concrete and the number of inches from the top of the cone to the top of the of specimen of concrete is the slump.  

Slump Cone A metal mold in the form of a truncated cone with a top diameter of 4”, a bottom diameter of 8”, and a height of 12”, used to fabricate the specimen for a slump test.

Slurry A mixture of water and such finely divided materials, such as portland cement, slag, or soil in suspension.

Spall 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.

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- T -

Tendon  A steel element such as a wire, cable, bar, rod, or strand used to impart pre-stress to concrete when the element is tensioned.

Tensile strength  Maximum unit stress which a material is capable of resisting under axial tensile loading, based on the cross sectional area of the specimen before loading.

Tilt-up A method of concrete construction where members are cast horizontally near their eventual position, usually on a recently placed slab,  and then tilted into place after removal of forms.

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- U -

Ultimate Strength The maximum resistance to loads that a structure or member is capable of developing before failure occurs, or, with reference to cross sections of members, the largest axial force, shear or moment a structural concrete cross section will support.
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- V -

Vibration Agitation of concrete to assist in its consolidation, produced by mechanical oscillating devices at moderately high frequencies.

A.       External vibration employs a device attached to the forms and is particularly applicable to the manufacture of precast items and for the vibration of tunnel lining forms.

B.       Internal vibration employs an element which can be inserted into the concrete; and is more generally used for cast-in-place construction.

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- W -

Water-Cement Ratio 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.
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- X -

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- Y -

Yard (of concrete)  One cubic yard of concrete is 3' x 3' x 3' in volume, or 27 cubic feet. One cubic yard of concrete will pour 80 square feet of 3.5' sidewalk or basement/garage floor.

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- Z -

Zero-slump concrete  A concrete mixture with so little water that it has a slump of zero.
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- # -

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Revised: 04/15/04.
Copyright © 2002, 2003, 2004 by Baumann Research and Development Corporation.
All trademarks or product names mentioned herein are the property of their respective owners.

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