|
A |
|
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A+B Contract |
Cost-plus-time bidding process where each contractor includes a time
cost bid along with their construction bid and the contractor selected has
the lowest combined bid total. |
|
AASHTO |
American Association of State Highway and Transportation Officials |
|
Absolute Specific Gravity |
The ratio of the weight referred to a vacuum of a given volume of
material at a stated temperature to the weight referred to a vacuum of an
equal volume of gas-free distilled water at the same temperature. |
|
Absolute Volume (of ingredients of concrete or mortar) |
The displacement volume of an ingredient of concrete or mortar; in the
case of solids, the volume of the particles themselves, including their
permeable or impermeable voids but excluding space between particles; in
the case of fluids, the volume which they occupy. |
|
Absorbed Moisture |
The moisture held in a material and having physical properties not
substantially different from those of ordinary water at the same
temperature and pressure. |
|
Absorbed Water |
Water held on surfaces of a material by physical and chemical forces,
and having physical properties substantially different from those of
absorbed water or chemically combined water at the same temperature and
pressure. |
|
Absorption |
The amount of water absorbed under specific conditions, usually
expressed as a percentage of the dry weight of the material; the process
by which the water is absorbed. |
|
Acceleration |
Increase in rate of hardening or strength development of concrete. |
|
Accelerator |
An admixture which, when added to concrete, mortar, or grout, increases
the rate of hydration of hydraulic cement, shortens the time of set, or
increases the rate of hardening or strength development. |
|
ACI |
American Concrete Institute |
|
ACPA |
American Concrete Pavement Association |
|
ACR |
Alkali-Carbonate Reaction |
|
Adhesion Loss |
The loss of bond between a joint sealant material and the concrete
joint face noted by physical separation of the sealant from either or both
joint faces. |
|
Adhesives |
The group of materials used to join or bond similar or dissimilar
materials; for example, in concrete work, the epoxy resins. |
|
Admixture |
A material other than water, aggregates, and portland cement (including
air-entraining portland cement, and portland blast furnace slag cement)
that is used as an ingredient of concrete and is added to the bath before
and during the mixing operation. |
|
Adsorption |
Development at the surface of a solid of a higher concentration of a
substance than exists in the bulk of the medium; especially in concrete
and cement technology, formation of a layer of water at the surface of a
solid, such as cement, or aggregate, or of air-entraining agents at the
air-water boundaries; the process by which a substance is adsorbed. |
|
Aggregate |
Granular material, such as sand, gravel, crushed stone, crushed
hydraulic-cement concrete, or iron blast furnace slag, used with a
hydraulic cementing medium to produce either concrete or mortar. |
|
Aggregate Blending |
The process of intermixing two or more aggregates to produce a
different set of properties, generally, but not exclusively, to improve
grading. |
|
Aggregate Gradation |
The distribution of particles of granular material among various sizes,
usually expressed in terms of cumulative percentages larger or smaller
than each of a series of sizes (sieve openings) or the percentages between
certain ranges of sizes (sieve openings). See also "Grading." |
|
Aggregate Interlock |
The projection of aggregate particles or portion of aggregate particles
from one side of a joint or crack in concrete into recesses in the other
side of the joint or crack so as to effect load transfer in compression
and shear and maintain mutual alignment. |
|
Aggregate, Angular |
Aggregate particles that possess well-defined edges formed at the
intersection of roughly planar faces. |
|
Aggregate, Coarse |
See Coarse Aggregate |
|
Aggregate, Dense-graded |
Aggregates graded to produce low void content and maximum weight when
compacted. |
|
Aggregate, Fine |
See Fine Aggregate |
|
Aggregate, Gap-graded |
Aggregate so graded that certain intermediate sizes are substantially
absent. |
|
Aggregate, Heavyweight |
Aggregate of high density, such as barite, magnetite, hematite,
limonite, ilmenite, iron, or steel, used to produce heavyweight concrete. |
|
Aggregate, Lightweight |
Aggregate of low density, such as (a) expanded or sintered clay, shale,
slate, diatomaceous shale, perlite, vermiculite, or slag; (b) natural
pumice, scoria, volcanic cinders, tuff, and diatomite; (c) sintered fly
ash or industrial cinders, used to produce lightweight concrete. |
|
Aggregate, Maximum Size |
See Maximum Size of Aggregate |
|
Aggregate, Nominal Maximum Size |
In specifications for and descriptions of aggregate, the smallest sieve
opening through which the entire amount of the aggregate is permitted to
pass; sometimes referred to as "maximum size (of aggregate)." |
|
Aggregate, Open-graded |
Concrete aggregate in which the voids are relatively large when the
aggregate is compacted. |
|
Aggregate-Cement Ratio |
See Cement-Aggregate Ratio |
|
Agitating Speed |
The rate of rotation of the drum or blades of a truck mixer when used
for agitation of mixed concrete. |
|
Agitating Truck |
A vehicle in which freshly mixed concrete can be conveyed from the
point of mixing to that of placing; while being agitated, the truck body
can either be stationary and contain an agitator or it can be a drum
rotated continuously so as to agitate the contents. |
|
Agitation |
The process of providing gentle motion in mixed concrete just
sufficient to prevent segregation or loss of plasticity. |
|
Agitator |
A device for maintaining plasticity and preventing segregation of mixed
concrete by agitation. |
|
Air Content |
The amount of air in mortar or concrete, exclusive of pore space in the
aggregate particles, usually expressed as a percentage of total volume of
mortar or concrete. |
|
Air Void |
A space in cement paste, mortar, or concrete filled with air; an
entrapped air void is characteristically 1 mm or more in size and
irregular in shape; an entrained air void is typically between 10 m and 1
mm in diameter and spherical (or nearly so). |
|
Air-Entraining |
The capabilities of a material or process to develop a system of minute
bubbles of air in cement paste, mortar, or concrete during mixing. |
|
Air-Entraining Agent |
An addition for hydraulic cement or an admixture for concrete or mortar
which causes air, usually in small quantity, to be incorporated in the
form of minute bubbles in the concrete or mortar during mixing, usually to
increase its workability and frost resistance. |
|
Air-Entraining Cement |
A cement that has an air-entraining agenda added during the grinding
phase of manufacturing. |
|
Air-Entrainment |
The inclusion of air in the form of minute bubbles during the mixing of
concrete or mortar. |
|
Air-Meter |
A device for measuring the air content of concrete and mortar. |
|
Air-Water Jet |
A high-velocity jet of air and water mixed at the nozzle, used in clean
up of surfaces of rock or concrete, such as horizontal construction joints. |
|
Alkali-Aggregate Reaction |
Chemical reaction in mortar or concrete between alkalis (sodium and
potassium) released from portland cement or from other sources, and
certain compounds present in the aggregates; under certain conditions,
harmful expansion of the concrete or mortar may be produced. |
|
Alkali-Carbonate Reaction |
The reaction between the alkalies (sodium and potassium) in portland
cement binder and certain carbonate rocks, particularly calcite dolomite
and dolomitic limestones, present in some aggregates; the products of the
reaction may cause abnormal expansion and cracking of concrete in service. |
|
Alkali-Silica Reaction |
The reaction between the alkalies (sodium and potassium) in portland
cement binder and certain siliceous rocks or minerals, such as opaline
chert, strained quartz, and acisic volcanic glass, present in some
aggregates; the products of the reaction may cause abnormal expansion and
cracking of concrete in service. |
|
Alternate Lane Construction |
A method of constructing concrete roads, runways, or other paved areas,
in which alternate lanes are placed and allowed to harden before the
remaining immediate lanes are placed. |
|
Angle of Repose |
The angle between the horizontal and the natural slope of loose
material below which the material will not slide. |
|
Area of Steel |
The cross-sectional area of the reinforcing bars in or for a given
concrete cross section. |
|
Artificial Turf Drag |
Surface texture achieved by inverting a section of artificial turf that
is attached to a device that allows control of the time and rate of
texturing. |
|
Asphalt |
A brown to black bituminous substance that is chiefly obtained as a
residue of petroleum refining and that consists mostly of hydrocarbons. |
|
ASR |
See, Alkali-Silica Reaction |
|
ASTM |
American Society for Testing and Materials |
|
Automatic Batcher |
A batcher equipped with gates or valves which, when actuated by a
single starter switch, will open automatically at the start of the
weighing operation of each material and close automatically when a
designated weight of each material has been reached, interlocked in such a
manner that (1) the charging mechanism cannot be opened until the scale
has returned to zero, (2) the charging mechanism cannot be opened if the
discharge mechanism is opened, (3) the discharge mechanism cannot be
opened if the charging mechanism is opened, (4) the discharge mechanism
cannot be opened until the designated weight has been reached within the
allowable tolerance, and (5) if different kinds of aggregates or different
kinds of cements are weighed cumulatively in a single batcher, interlocked
sequential controls are provided. |
|
Axle Load |
The portion of the gross weight of a vehicle transmitted to a structure
or a pavement through wheels supporting a given axle. |
|
B |
|
|
Backer Rod |
Foam cord that inserts into a joint sealant reservoir and is used to
shape a liquid joint sealant and prevent sealant from adhering to or
flowing out of the bottom of the reservoir. |
|
Bag (of cement) |
A quantity of cement; 42.6 kg in the United States, 39.7 kg in Canada;
portland or air-entraining portland cement, or as indicated on the bag for
other kinds of cement. |
|
Ball Test |
A test to determine the consistency of fresh concrete by measuring the
depth of penetration of a steel ball. The apparatus is usually called a
Kelly ball. |
|
Bar |
A member used to reinforce concrete, usually made of steel. |
|
Bar Chair |
An individual supporting device used to support or hold reinforcing
bars in proper position to prevent displacement before or during
concreting. |
|
Bar Spacing |
The distance between parallel reinforcing bars, measured center to
center of the bars perpendicular to their longitudinal axis. |
|
Bar Support |
A rigid device used to support or hold reinforcing bars in proper
position to prevent displacement before or during concrete placing. |
|
Barrel (of cement) |
A unit of weight for cement: (170.6 kg) net, equivalent to 4 US bags
for portland or air-entraining portland cements, or as indicated by the
manufacturer for other kinds of cement. (In Canada, 158.8 kg. net per
barrel). |
|
Base |
A subfloor slab or "working mat," either previously placed
and hardened or freshly placed, on which floor topping is placed in a
later operation; also, the underlying stratum on which a concrete slab,
such as a pavement, is placed. |
|
Base Course |
A layer of specified select material of planned thickness constructed
on the subgrade or subbase below a pavement to serve one or more functions
such as distributing loads, providing drainage, minimizing frost action,
or facilitating pavement construction. |
|
Batch |
Quantity of concrete or mortar mixed at one time. |
|
Batch Plant |
Equipment used for batching concrete materials. |
|
Batch Weights |
The weights of the various materials (cement, water, the several sizes
of aggregate, and admixtures) that compose a batch of concrete. |
|
Batched Water |
The mixing water added to a concrete or mortar mixture before or during
the initial stages of mixing. |
|
Batching |
Weighing or volumetrically measuring and introducing into the mixer the
ingredients for a batch of concrete or mortar. |
|
Beam Test |
A method of measuring the flexural strength (modulus of rupture) of
concrete by testing a standard unreinforced beam. |
|
Benkelman Beam |
Static deflection measuring tool equipped with dial gauges able to
detect slab deflection to 0.025 millimeters. |
|
Binder |
See Cement Paste |
|
Bitumen |
Any of various mixtures of hydrocarbons (as tar) often together with
their non-metallic derivatives that occur naturally or are obtained as
residues after heat-refining petroleum |
|
Bituminous |
Resembling, containing or impregnated with bitumen. |
|
Blanking Band |
A plastic scale, or computer-generated scale, 1.7 inches wide and 21.12
inches long representing a length of 0.1 miles on a profilograph trace.
The opaque blanking strip, running the length of the scale and located at
its midpoint, covers the profile trace. Typically, a bandwidth of 0.0 to
0.2 in. is used. |
|
Blast Furnace Slag |
The non-metallic by-product, consisting essentially of silicates and
aluminosilicates of lime and other bases, which is produced in a molten
condition simultaneously with iron in a blast furnace. |
|
Bleeding |
The self-generated flow of mixing water within, or its emergence from,
freshly placed concrete or mortar. |
|
Bleeding Rate |
The rate at which water is released from a paste or mortar by bleeding,
usually expressed as cubic centimeters of water released each second from
each square centimeter of surface. |
|
Blemish |
Any superficial defect that causes visible variation from a
consistently smooth and uniformly colored surface of hardened concrete. (See
also Bug Holes, Efflorescence, Honeycomb, Laitance, Popout, Rock Pocket,
Sand streak.) |
|
Blended Cement |
See Cement, Blended |
|
Blended Hydraulic Cement |
See Cement, Blended |
|
Blistering |
The irregular rising of a thin layer of placed mortar or concrete at
the surface during or soon after completion of the finished operation. |
|
Bond |
The adhesion of concrete or mortar to reinforcement or other surfaces
against which it is placed; the adhesion of cement paste to aggregate. |
|
Bond Area |
The interface area between two elements across which adhesion develops
or may develop, as between concrete and reinforcing steel. |
|
Bond Breaker |
A material used to prevent adhesion of newly placed concrete from other
material, such as a substrate. |
|
Bond Hardness |
The support (bond strength) that the metal matrix in a diamond saw
blade segment provides to each diamond that is embedded within the matrix. |
|
Bond Strength |
Resistance to separation of mortar and concrete from reinforcing steel
and other materials with which it is in contact; a collective expression
for all forces such as adhesion, friction due to shrinkage, and
longitudinal shear in the concrete engaged by the bar deformations that
resist separation. |
|
Bond Stress |
The force of adhesion per unit area of contact between two surfaces
such as concrete and reinforcing steel or any other material such as
foundation rock. |
|
Bonded Concrete Overlay |
Thin layer of new concrete (2-4 inches) placed onto slightly
deteriorated existing concrete pavement with steps taken to prepare old
surface to promote adherence of new concrete. |
|
Bonding Agent |
A substance applied to an existing surface to create a bond between it
and a succeeding layer, as between a bonded overlay and existing concrete
pavement. |
|
Box Out |
To form an opening or pocket in concrete by a box-like form; Used for
manholes, drainage inlets and other in-pavement objects.. |
|
Broom |
The surface texture obtained by stroking a broom over freshly placed
concrete. A sandy texture obtained by brushing the surface of freshly
placed or slightly hardened concrete with a stiff broom. |
|
Bug Holes |
Small regular or irregular cavities, usually not exceeding 15 mm in
diameter, resulting from entrapment of air bubbles in the surface of
formed concrete during placement and compaction. |
|
Bulk Cement |
Cement that is transported and delivered in bulk (usually in specially
constructed vehicles) instead of in bags. |
|
Bulk Density |
The mass of a material (including solid particles and any contained
water) per unit volume, including voids. |
|
Bulk Specific Gravity |
The ratio of the weight in air of a given volume of a permeable
material (including both permeable and impermeable voids normal to the
material) at a stated temperature to the weight in air of an equal volume
of distilled water at the same temperature. |
|
Bulking Factor |
Ratio of the volume of moist sand to the volume of the sand when dry. |
|
Bull Float |
A tool comprising a large, flat, rectangular piece of wood, aluminum,
or magnesium usually 20 cm wide and 100 to 150 cm long, and a handle 1 to
5 m in length used to smooth unformed surfaces of freshly placed concrete. |
|
Burlap |
A coarse fabric of jute, hemp, or less commonly flax, for use as a
water-retaining cover for curing concrete surfaces; also called Hessian. |
|
Burlap Drag |
Surface texture achieved by trailing moistened coarse burlap from a
device that allows control of the time and rate of texturing. |
|
Butt Joint |
A plain square joint between two concrete slabs. |
|
C |
|
|
Calcareous |
Containing calcium carbonate, or less generally, containing the element
calcium. |
|
Calcium Chloride |
A crystalline solid, CaC12; in various technical grades, used as a
drying agent, as an accelerator of concrete, a deicing chemical, and for
other purposes. |
|
Calcium Lignosulfonate |
An admixture, refined from papermaking wastes, employed in concrete to
retard the set of cement, reduce water requirement and increase strength. |
|
Caliche |
Gravel, sand, or desert debris cement by porous calcium carbonate or
other salts. |
|
California Bearing Ratio |
The ratio of the force per unit area required to penetrate a soil mass
with a 19.4 sq cm circular piston at the rate of 1.27 mm per min to the
force required for corresponding penetration of a standard crushed-rock
base material; the ratio is usually determined at 2.5 mm penetration. |
|
California Profilograph |
Rolling straight edge tool used for evaluating pavement profile (smoothness)
consisting of a 25-ft frame with a sensing wheel located at the center of
the frame that senses and records bumps and dips on graph paper or in a
computer. |
|
Capillary |
In cement paste, any space not occupied by unhydrated cement or cement
gel (air bubbles, whether entrained or entrapped, are not considered to be
part of the cement paste). |
|
Capillary Absorption |
The action of surface tension forces which draws water into capillaries
(i.e., in concrete) without appreciable external pressures. |
|
Capillary Flow |
Flow of moisture through a capillary pore system, such as concrete. |
|
Capillary Space |
In cement paste, any space not occupied by anhydrous cement or cement
gel. (Air bubbles, whether entrained or entrapped, are not considered to
be part of the cement paste.) |
|
Capillary Transmission |
Passage of water or other fluid through capillaries, either by
capillarity or under hydraulic pressure; capillary flow. |
|
Carbide-Milling |
Surface removal or sawing done with carbide milling machine; Machine
uses blade or arbor equipped with carbide-tipped teeth that impact and
chip concrete or asphalt. |
|
Carbonation |
Reaction between carbon dioxide and the products of portland cement
hydration to produce calcium carbonate. |
|
Cast-In-Place |
Concrete placed and finished in its final location. |
|
Cement |
See Portland Cement |
|
Cement Content |
Quantity of cement contained in a unit volume of concrete or mortar,
ordinarily expressed as pounds, barrels, or bags per cubic yard. |
|
Cement Factor |
See Cement Content |
|
Cement Paste |
Constituent of concrete consisting of cement and water. |
|
Cement, Blended |
A hydraulic cement consisting essentially of an intimate and uniform
blend of granulated blast-furnace slag and hydrated lime; or an intimate
and uniform blend of portland cement and granulated blast-furnace slag
cement and pozzolan, produced by intergrinding Portland cement clinker
with the other materials or by blending Portland cement with the other
materials, or a combination of intergrinding and blending. |
|
Cement, Expansive |
A special cement which, when mixed with water, forms a paste that tends
to increase in volume at an early age; used to compensate for volume
decrease due to drying shrinkage. |
|
Cement, High-Early-Strength |
Cement characterized by producing earlier strength in mortar or
concrete than regular cement, referred to in the United States as "Type
III." |
|
Cement, Hydraulic |
Cement that is capable of setting and hardening under water, such as
normal portland cement. |
|
Cement, Normal |
General purpose portland cement, referred to in the United States as
"Type I." |
|
Cement, Portland-Pozzolan |
A hydraulic cement consisting essentially of an intimate and uniform
blend of portland cement or portland blast-furnace slag cement and fine
pozzolan produced by intergrinding portland-cement clinker and pozzolan,
by blending portland cement or portland blast-furnace slag cement and
finely divided pozzolan, or a combination of intergrinding and blending,
in which the pozzolan constituent is within specified limits. |
|
Cement-Aggregate Ratio |
The ratio, by weight or volume, of cement to aggregate. |
|
Cementitious |
Having cementing properties. |
|
Cementitious materials |
Substances that alone have hydraulic cementing properties (set and
harden in the presence of water). Includes: ground granulated blast
furnace slag, natural cement, hydraulic hydrated lime, and combinations of
these and other materials. |
|
Central Mixer |
A stationary concrete mixer from which the fresh concrete is
transported to the work. |
|
Central-Mixed Concrete |
Concrete that is completely mixed in a stationary mixer from which it
is transported to the delivery point. |
|
Chair |
See Bar Support |
|
Chalking |
A phenomenon of coatings, such as cement paint, manifested by the
formation of a loose powder by deterioration of the paint at or just
beneath the surface. |
|
Charging |
Introducing, feeding, or loading materials into a concrete or mortar
mixer, furnace, or other container or receptacle. |
|
Checking |
Development of shallow cracks at closely spaced but irregular intervals
on the surface of mortar or concrete. |
|
Chipping |
Treatment of a hardened concrete surface by chiseling away a portion of
material. |
|
Chute |
A sloping trough or tube for conducting concrete, cement, aggregate, or
other free-flowing materials from a higher to a lower point. |
|
Coarse Aggregate |
See Aggregate, Coarse |
|
Coefficient of Thermal Expansion |
Change in linear dimension per unit length or change in volume per unit
volume per degree of temperature change. |
|
Cohesion Loss |
The loss of internal bond within a joint sealant material; noted by a
noticeable tear along the surface and through the depth of the sealant. |
|
Cohesiveness |
The property of a concrete mix which enables the aggregate particles
and cement paste matrix therein to remain in contact with each other
during mixing, handling, and placing operations; the "stick-togetherness"
of the concrete at a given slump. |
|
Cold Joint |
A discontinuity produced when the concrete surface hardens before the
next batch is placed against it. |
|
Colloidal Mixer |
Grout mixing device that uses a high velocity blade to shear or
separate Cementitious particles in order to break surface tension and
enable complete contact between the particles and mixing water. |
|
Combined Aggregate Grading |
Particle size distribution of a mixture of fine and coarse aggregate. |
|
Compacting Factor |
The ratio obtained by dividing the observed weight of concrete which
fills a container of standard size and shape when allowed to fall into it
under standard conditions of test, by the weight of fully compacted
concrete which fills the same container. |
|
Compaction |
The process whereby the volume of freshly placed mortar or concrete is
reduced to the minimum practical space, usually by vibration,
centrifugation, tamping, or some combination of these; to mold it within
forms or molds and around embedded parts and reinforcement, and to
eliminate voids other than entrained air. See also Consolidation. |
|
Compressible Insert |
Board used to separate a partial-depth patch from an adjacent slab,
usually consisting of a 12-mm thick Styrofoam or compressed fiber material
that is impregnated with asphalt. |
|
Compression Seal |
See Preformed Compression Seal |
|
Compression Test |
Test made on a specimen of mortar or concrete to determine the
compressive strength; in the United States, unless otherwise specified,
compression tests of mortars are made on 50-mm cubes, and compression
tests of concrete are made on cylinders 152 mm in diameter and 305 mm high. |
|
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. |
|
Concrete |
A composite material that consists essentially of a binding medium in
which is embedded particles or fragments of relatively inert material
filler. In portland cement concrete, the binder is a mixture of portland
cement and water; the filler may be any of a wide variety of natural or
artificial aggregates. |
|
Concrete Spreader |
A machine designed to spread concrete from heaps already dumped in
front of it, or to receive and spread concrete in a uniform layer. |
|
Concrete, Normal-weight |
Concrete having a unit weight of approximately 2400 kg/m3 made with
aggregates of normal weight. |
|
Concrete, Reinforced |
Concrete construction that contains mesh or steel bars embedded in it. |
|
Consistency |
The relative mobility or ability of fresh concrete or mortar to flow.
The usual measures of consistency are slump or ball penetration for
concrete and flow for mortar. |
|
Consolidate |
Compaction usually accomplished by vibration of newly placed concrete
to minimum practical volume, to mold it within form shapes or around
embedded parts and reinforcement, and to reduce void content to a
practical minimum. |
|
Consolidation |
The process of inducing a closer arrangement of the solid particles in
freshly mixed concrete or mortar during placement by the reduction of
voids, usually by vibration, centrifugation, tamping, or some combination
of these actions; also applicable to similar manipulation of other
cementitious mixtures, soils, aggregates, or the like. See also Compaction. |
|
Construction Joint |
The junction of two successive placements of concrete, typically with a
keyway or reinforcement across the joint. |
|
Continuously Reinforced Pavement |
A pavement with continuous longitudinal steel reinforcement and no
intermediate transverse expansion or contraction joints. |
|
Contract |
Decrease in length or volume. (See also Expand, Shrinkage, Swelling,
and Volume Change.) |
|
Contraction Joint |
A plane, usually vertical, separating concrete in a structure of
pavement, at a designated location such as to prevent formation of
objectionable shrinkage cracks elsewhere in the concrete. Reinforcing
steel is discontinuous. |
|
Control Joint |
See Contraction Joint |
|
Core |
A cylindrical specimen of standard diameter drilled from a structure or
rock foundation to be bested in compression or examined petrographically. |
|
Corner Break |
A portion of the slab separated by a crack that intersects the adjacent
transverse or longitudinal joints at about a 45º angle with the direction
of traffic. The length of the sides is usually from 0.3 meters to one-half
of the slab width on each side of the crack. |
|
Course |
In concrete construction, a horizontal layer of concrete, usually one
of several making up a lift; in masonry construction, a horizontal layer
of block or brick. See also Lift. |
|
Cover |
In reinforced concrete, the least distance between the surface of the
reinforcement and the outer surface of the concrete. |
|
CPCD |
Concrete pavement contraction design; term used in Texas for jointed
plain concrete pavement (see JPCP). |
|
CPR |
Concrete pavement restoration; the combination of available concrete
repair techniques in one project. |
|
Crack Saw |
Small three-wheeled specialty saw useful for tracing the wandering
nature of a transverse or longitudinal crack; usually contains a pivot
wheel and requires a small diameter crack sawing blade. |
|
Cracking |
The process of contraction or the reflection of stress in the pavement. |
|
Crazing |
Minute surface pattern cracks in mortar or concrete due to unequal
shrinkage or contraction on drying or cooling. |
|
CRC Pavement (CRCP) |
Continuously reinforced concrete pavement; see Continuously Reinforced
Pavement. |
|
Cross Section |
The section of a body perpendicular to a given axis of the body; a
drawing showing such a section. |
|
Crushed Gravel |
The product resulting from the artificial crushing of gravel with a
specified minimum percentage of fragments having one or more faces
resulting from fracture. See also Coarse Aggregate. |
|
Crushed Stone |
The product resulting from the artificial crushing of rocks, boulders,
or large cobblestones, substantially all faces of which possess well-defined
edges and have resulted from the crushing operation. |
|
Crusher-run Aggregate |
Aggregate that has been broken in a mechanical crusher and has not been
subjected to any subsequent screening process. |
|
Cubic Yard |
Normal commercial units of measure of concrete volume, equal to 27
cubic feet. |
|
Cure |
Maintenance of temperature and humidity for freshly placed concrete
during some definite period following placing and finishing to ensure
proper hydration of the cement and proper hardening of the concrete. |
|
Curing |
The maintenance of a satisfactory moisture content and temperature in
concrete during its early stages so that desired properties may develop. |
|
Curing Blanket |
A built-up covering of sacks, matting, Hessian, straw, waterproof paper,
or other suitable material placed over freshly finished concrete. See also
Burlap. |
|
Curing Compound |
A liquid that can be applied as a coating to the surface of newly
placed concrete to retard the loss of water or, in the case of pigmented
compounds, also to reflect heat so as to provide an opportunity for the
concrete to develop its properties in a favorable temperature and moisture
environment. See also Curing. |
|
D |
|
|
Damp |
Either moderate absorption or moderate covering of moisture; implies
less wetness than that connoted by "wet," and slightly wetter
than that connoted by "moist." See also Moist and Wet. |
|
DBI |
A dowel bar inserter that places the load transfer bars into plastic
concrete as part of the paving operation. |
|
Deformed Bar |
A reinforcing bar with a manufactured pattern of surface ridges that
provide a locking anchorage with surrounding concrete. |
|
Deformed Reinforcement |
Metal bars, wire, or fabric with a manufactured pattern of surface
ridges that provide a locking anchorage with surrounding concrete. |
|
Density |
Mass per unit volume; by common usage in relation to concrete, weight
per unit volume, also referred to as unit weight. |
|
Density (dry) |
The mass per unit volume of a dry substance at a stated temperature.
See also Specific Gravity. |
|
Density Control |
Control of density of concrete in field construction to ensure that
specified values as determined by standard tests are obtained. |
|
Design Strength |
Load capacity of a member computed on the basis of allowable stresses
assumed in design. |
|
Deterioration |
1) Physical manifestation of failure (e.g., cracking delamination,
flaking, pitting, scaling, spalling, staining) caused by environmental or
internal autogenous influences on rock and hardened concrete as well as
other materials; 2) decomposition of material during either testing or
exposure to service. See also Disintegration and Weathering. |
|
Diamond Grinding |
The process used to remove the upper surface of a concrete pavement to
remove bumps and restore pavement rideability; also, equipment using many
diamond-impregnated saw blades on a shaft or arbor to shave the surface of
concrete slabs. |
|
Disincentive |
Deduction in payment resulting from a measured quality lower than
specified for full payment. |
|
Dispersing Agent |
Admixtures capable of increasing the fluidity of pastes, mortar or
concretes by reduction of inter-particle attraction. |
|
Distress |
Physical manifestation of deterioration and distortion in a concrete
structure as the result of stress, chemical action, and/or physical action. |
|
Dolomite |
A mineral having a specific crystal structure and consisting of calcium
carbonate and magnesium carbonate in equivalent chemical amounts (54.27
and 45.73 percent by weight, respectively); a rock containing dolomite as
the principal constituent. |
|
Dowel |
1) A steel pin, commonly a plain round steel bar, which extends into
two adjoining portions of a concrete construction, as at a joint in a
pavement slab, so as to transfer shear loads; 2) a deformed reinforcing
bar intended to transmit tension, compression, or shear through a
construction joint. |
|
Dowel Basket |
See Load-Transfer Assembly |
|
Down Pressure |
The force that keeps the grinding head on a diamond grinding machine
cutting through bumps in the concrete surface and prevents the grinding
head from riding up and merely tracing the bump profile. |
|
Drainage |
The interception and removal of water from, on, or under an area or
roadway; the process of removing surplus ground or surface water
artificially; a general term for gravity flow of liquids in conduits. |
|
Drive Packer |
For slab stabilization or slab jacking, tapering metal nozzle that
seats into an injection hole by tapping or standing on footplate. Usually
most appropriate for small-diameter holes. |
|
Drop Hammer |
Impact-type pavement breaking equipment. |
|
Dry Mix |
Concrete, mortar, or plaster mixture, commonly sold in bags, containing
all components except water; also a concrete of near zero slump. |
|
Dry Mixing |
Blending of the solid materials for mortar or concrete prior to adding
the mixing water. |
|
Dry Process |
In the manufacture of cement, the process in which the raw materials
are ground, conveyed, blended, and stored in a dry condition. See also Wet
Process. |
|
Drying Shrinkage |
Contraction caused by drying. |
|
Dry-Rodded Volume |
The volume that would be occupied by an aggregate if it were compacted
dry under the standardized conditions used in measuring unit weight of
aggregate. |
|
Durability |
The ability of concrete to remain unchanged while in service;
resistance to weathering action, chemical attack, and abrasion. |
|
Dynamic Load |
A variable load; i.e., not static, such as a moving live load,
earthquake, or wind. |
|
Dynamic Loading |
Loading from units (particularly machinery) which, by virtue of their
movement or vibration, impose stresses in excess of those imposed by their
dead load. |
|
E |
|
|
Early Strength |
Strength of concrete developed soon after placement, usually during the
first 72 hours. |
|
Early-Entry Dry Saw |
Lightweight saw equipped with a blade that does not require water for
cooling and that allows sawing concrete sooner than with conventional wet-diamond
sawing equipment. |
|
Econocrete |
Portland cement concrete designed for a specific application and
environment and, in general, making use of local commercially produced
aggregates. These aggregates do not necessarily meet conventional quality
standards for aggregates used in pavements. |
|
Edge Form |
Formwork used to limit the horizontal spread of fresh concrete on flat
surfaces, such as pavements or floors. |
|
Edger |
A finishing tool used on the edges of fresh concrete to provide a
rounded edge. |
|
Efflorescence |
Deposit of calcium carbonate (or other salts), usually white in color,
appearing upon the surface or found within the near-surface pores of
concrete. The salts deposit on concrete upon evaporation of water that
carries the dissolved salts through the concrete toward exposed surfaces. |
|
End-Result Specification |
Specification that requires the contractor to take the entire
responsibility for supplying each item of construction. The highway
agency's responsibility is to either except or reject the final product or
apply a price adjustment that compensates for the degree of compliance
with the specification. |
|
Entrained Air |
Round, uniformly distributed, microscopic, non-coalescing air bubbles
entrained by the use of air-entraining agents; usually less than 1 mm in
size. |
|
Entrapped Air |
Air in concrete that is not purposely entrained. Entrapped air is
generally considered to be large voids (larger than 1 mm). |
|
Evaporable Water |
Water set in cement paste present in capillaries or held by surface
forces; measured as that removable by drying under specified conditions.
See also Nonevaporable Water. |
|
Expanding Rubber Packer |
For slab stabilization or slab jacking, nozzle containing an expandable
rubber sleeve that expands from injection pressure to fill the injection
hole during injection of stabilizing material. |
|
Expansion |
Increase in length or volume. See also Autogenous Volume Change,
Contraction, Moisture Movement, Shrinkage, and Volume Change. |
|
Expansion Joint |
See Isolation Joint |
|
Expansion Sleeve |
A tubular metal covering for a dowel bar to allow its free longitudinal
movement at a joint. |
|
Exposed Aggregate |
Surface texture where cement paste is washed away from concrete slab
surface to expose durable chip-size aggregates for the riding surface. |
|
Exposed Concrete |
Concrete surfaces formed so as to yield an acceptable texture and
finish for permanent exposure to view. See also Architectural Concrete. |
|
External Vibrator |
See Vibration |
|
F |
|
|
False Set |
The rapid development of rigidity in a freshly mixed Portland cement
paste, mortar, or concrete without the evolution of much heat, which
rigidity can be dispelled and plasticity regained by further mixing
without addition of water; premature stiffening, hesitation set, early
stiffening, and rubber set are terms referring to the same phenomenon, but
false set is the preferred designation. |
|
Fast-Track |
Series of techniques to accelerate concrete pavement construction. |
|
Faulting |
Differential vertical displacement of a slab or other member adjacent
to a joint or crack. |
|
FHWA |
Federal Highway Administration |
|
Fibrous Concrete |
Concrete containing dispersed, randomly oriented fibers. |
|
Field-cured Cylinders |
Test cylinders cured as nearly as practicable in the same manner as the
concrete in the structure to indicate when supporting forms may be removed,
additional construction loads may be imposed, or the structure may be
placed in service. |
|
Final Set |
A degree of stiffening of a mixture of cement and water greater than
initial set, 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;
also applicable to concrete and mortar mixtures with use of suitable test
procedures. See also Initial Set. |
|
Final Setting Time |
The time required for a freshly mixed cement paste, mortar, or concrete
to achieve final set. See also Initial Setting Time. |
|
Fine Aggregate |
Aggregate passing the 3/8-inch (9.5 mm) sieve and almost entirely
passing the No. 4 (4.75-mm) sieve and predominantly retained on the No.
200 (75 mm) sieve. |
|
Finish |
The texture of a surface after compacting and finishing operations has
been performed. |
|
Finishing |
Leveling, smoothing, compacting, and otherwise treating surfaces of
fresh or recently placed concrete or mortar to produce desired appearance
and service. See also Float and Trowel. |
|
Finishing Machine |
A power-operated machine used to give the desired surface texture to a
concrete slab. |
|
Fixed Form Paving |
A type of concrete paving process that involves the use of fixed forms
to uniformly control the edge and alignment of the pavement. |
|
Flash Set |
The rapid development of rigidity in a freshly mixed Portland cement
paste, mortar, or concrete, usually with the evolution of considerable
heat, which rigidity cannot be dispelled nor can the plasticity be
regained by further mixing without addition of water; also referred to as
quick set or grab set. |
|
Flexible Pavement |
A pavement structure that maintains intimate contact with and
distributes loads to the subgrade and depends on aggregate interlock,
particle friction, and cohesion for stability; cementing agents, where
used, are generally bituminous materials as contrasted to portland cement
in the case of rigid pavement. See also Rigid Pavement. |
|
Flexural Strength |
A property of a material or structural member that indicates its
ability to resist failure in bending. See also Modulus of Rupture. |
|
Float |
A tool (not a darby) usually of wood, aluminum, or magnesium, used in
finishing operations to impart a relatively even but still open texture to
an unformed fresh concrete surface. |
|
Float Finish |
A rather rough concrete surface texture obtained by finishing with a
float. |
|
Floating |
Process of using a tool, usually wood, aluminum, or magnesium, in
finishing operations to impart a relatively even but still open texture to
an unformed fresh concrete surface. |
|
Flow |
1) Time dependent irrecoverable deformation. See Rheology. 2) A measure
of the consistency of freshly mixed concrete, mortar, or cement paste in
terms of the increase in diameter of a molded truncated cone specimen
after jigging a specified number of times. |
|
Flow Cone Test |
Test that measures the time necessary for a known quantity of grout to
completely flow out of and empty a standard sized cone; usually used in
slab stabilization to determine the water quantity necessary for
stabilization grout. |
|
Fly Ash |
The finely divided residue resulting from the combustion of ground or
powdered coal and which is transported from the fire box through the
boiler by flu gasses; Used as mineral admixture in concrete mixtures. |
|
Form |
A temporary structure or mold for the support of concrete while it is
setting and gaining sufficient strength to be self-supporting. |
|
Form Oil |
Oil applied to interior surface of formwork to promote easy release
from the concrete when forms are removed. |
|
Free Moisture |
Moisture having essentially the properties of pure water in bulk;
moisture not absorbed by aggregate. See also Surface Moisture. |
|
Free Water |
See Free Moisture and Surface Moisture |
|
Full-depth Patching |
Removing and replacing at least a portion of a concrete slab to the
bottom of the concrete, in order to restore areas of deterioration. |
|
Full-Depth Repair |
See "Full-Depth Patching" |
|
G |
|
|
Gap-graded Concrete |
Concrete containing a gap-graded aggregate. |
|
Gradation |
See Grading |
|
Grading |
The distribution of particles of granular material among various sizes,
usually expressed in terms of cumulative percentages larger or smaller
than each of a series of sizes (sieve openings) or the percentages between
certain ranges of sizes (sieve openings). |
|
Gravel |
Granular material predominantly retained on the 4.75 mm (No. 4) sieve
and resulting from natural disintegration and abrasion of rock or
processing of weakly bound conglomerate. |
|
Green Concrete |
Concrete that has set but not appreciably hardened. |
|
Green Sawing |
The process of controlling random cracking by sawing uniform joint
spacing in early age concrete without tearing or dislocating the aggregate
in the mix. |
|
Grinding Head |
Arbor or shaft containing many diamond blades on diamond grinding
equipment. |
|
Grooving |
The process used to cut slots into a concrete pavement surface to
provide channels for water to escape beneath tires and to promote skid
resistance. |
|
Gross Vehicle Load |
The weight of a vehicle plus the weight of any load thereon. |
|
Gross Volume
(of concrete mixers) |
In the case of a revolving-drum mixer, the total interior volume of the
revolving portion of the mixer drum; in the case of an open-top mixer, the
total volume of the trough or pan calculated on the basis that no vertical
dimension of the container exceeds twice the radius of the circular
section below the axis of the central shaft. |
|
Grout |
A mixture of cementitious material and water, with or without aggregate,
proportioned to produce a pourable consistency without segregation of the
constituents; also, a mixture of other composition but of similar
consistency. See also Neat Cement Grout and Sand Grout. |
|
Grout-Retention Disk |
Small plastic disk that provides a barrier that prevents grout or epoxy
from escaping from a dowel hole. |
|
H |
|
|
Hairline Cracking |
Barely visible cracks in random pattern in an exposed concrete surface
which do not extend to the full depth or thickness of the concrete, and
which are due primarily to drying shrinkage. |
|
Hardener |
A chemical applied to concrete floors to reduce wearing and dusting. |
|
Hardening |
When portland cement is mixed with enough water to form a paste, the
compounds of the cement react with water to form cementitious products
that adhere to each other and to the intermixed sand and stone particles
and become very hard. As long as moisture is present, the reaction may
continue for years, adding continually to the strength of the mixture. |
|
Harsh Mixture |
A concrete mixture that lacks desired workability and consistency due
to a deficiency of mortar. |
|
Harshness |
Deficient workability and cohesiveness caused by insufficient sand or
cement, or by improperly graded aggregate. |
|
Header |
A transverse construction joint installed at the end of a paving
operation or other placement interruptions. To a contractor, a header is
the location at which paving will resume on the next day. |
|
Heat of Hydration |
Heat evolved by chemical reactions of a substance with water, such as
that evolved during the setting and hardening of portland cement. |
|
Heavy-Weight Aggregate |
An aggregate of very high unit weight, such as barium, boron, or iron
ore, steel shot or punchings, which forms a high density mortar of
concrete when bound together with hardened cement paste. |
|
Heavy-Weight Concrete |
Concrete in which heavy aggregate is used to increase the density of
the concrete; unit weights in the range of 165 to 330 pounds per cubic
foot are attained. |
|
High Density Polyurethane |
Also, HDP; Polyurethane used in slab stabilization or slab jacking
process. |
|
High Range Water-Reducing Admixture |
See Water-Reducing Admixture (high range) |
|
High-Early-Strength Cement |
See Cement, High-Early-Strength |
|
High-Early-Strength Concrete |
Concrete that, through the use of high-early-strength cement or
admixtures, is capable of attaining specified strength at an earlier age
than normal concrete. |
|
Holiday |
An area in a diamond ground surface that is not ground because the head
on the diamond grinding equipment does not cut deep enough to touch a low
spot in the surface. |
|
Honeycomb |
Concrete that, due to lack of the proper amount of fines or vibration,
contains abundant interconnected large voids or cavities; concrete that
contains honeycombs was improperly consolidated. |
|
Hooked Bar |
A reinforcing bar with the end bent into a hook to provide anchorage. |
|
Horizontal-Axis Mixer |
Concrete mixers of the revolving drum type in which the drum rotates
about a horizontal axis. |
|
Hot-pour Sealant |
Joint sealing materials that require heating for installation, usually
consisting of a base of asphalt or coal tar. |
|
Hydrated Lime |
A dry powder obtained by treating quicklime with sufficient water to
convert it to calcium hydroxide. |
|
Hydration |
The chemical reaction between cement and water which causes concrete to
harden. |
|
Hydraulic Cement |
A cement that is capable of setting and hardening under water due to
the chemical interaction of the water and the constituents of the cement. |
|
Hydraulic Ram |
Impact-type pavement breaking equipment. |
|
Hydroplaning |
To go out of steering control by skimming the surface of a wet road. |
|
I |
|
|
Incentive |
Additional payment to the contractor resulting from a measured quality
higher than specified for full payment. |
|
Inclined-Axis Mixer |
A truck with a revolving drum that rotates about an axis inclined to
the bed of the truck chassis. |
|
Incompressibles |
Small concrete fragments, stones, sand or other hard materials that
enter a joint sealant, joint reservoir, or other concrete pavement
discontinuity. |
|
Initial Set |
A degree of stiffening of a mixture of cement and water less than final
set, generally stated as an empirical value indicating the time in hours
and minutes required for cement paste to stiffen sufficiently to resist to
an established degree the penetration of a weighted test needle; also
applicable to concrete or mortar with use of suitable test procedures. See
also Final Set. |
|
Initial Setting Time |
The time required for a freshly mixed cement paste to acquire an
arbitrary degree of stiffness as determined by specific test. |
|
Injection Hole |
Hole drilled vertically through a concrete slab that is used to inject
stabilizing grout underneath the slab or subbase layers. |
|
Inlay |
A form of reconstruction where new concrete is placed into an area of
removed pavement; The removal may be an individual lane, all lanes between
the shoulders or only partly through a slab, . |
|
Isolation Joint |
A pavement joint that allows relative movement in three directions and
avoids formation of cracks elsewhere in the concrete and through which all
or part of the bonded reinforcement is interrupted. large closure movement
to prevent development of lateral compression between adjacent concrete
slabs; usually used to isolate a bridge. |
|
J |
|
|
Jitterbug |
A grate tamper for pushing coarse aggregate slightly below the surface
of a slab to facilitate finishing. See also Tamper. |
|
Joint |
A plane of weakness to control contraction cracking in concrete
pavements. A joint can be initiated in plastic concrete or green concrete
and shaped with later process. |
|
Joint Depth |
The measurement of a saw cut from the top of the slab to the bottom of
the cut. |
|
Joint Deterioration |
See Spalling, Compression |
|
Joint Filler |
Compressible material used to fill a joint to prevent the infiltration
of debris and to provide support for sealant. |
|
Joint Sealant |
Compressible material used to minimize water and solid debris
infiltration into the sealant reservoir and joint. |
|
Joint Shape Factor |
Ratio of the vertical to horizontal dimension of the joint sealant
reservoir. |
|
Joint, Construction |
See Construction Joint |
|
Joint, Contraction |
See Contraction Joint |
|
Joint, Expansion |
See Expansion Joint |
|
Jointed Plain Concrete Pavement
(JPCP) |
Pavement containing enough joints to control all natural cracks
expected in the concrete; steel tie bars are generally used at
longitudinal joints to prevent joint opening, and dowel bars may be used
to enhance load transfer at transverse contraction joints depending upon
the expected traffic. |
|
Jointed Reinforced Concrete Pavement
(JRCP) |
Pavement containing some joints and embedded steel mesh reinforcement (sometimes
called distributed steel) to control expected cracks; steel mesh is
discontinued at transverse joint locations. |
|
K |
|
|
Keyway |
A recess or groove in one lift or placement of concrete which is filled
with concrete of the next lift, giving shear strength to the joint. See
also Tongue and Groove. |
|
L |
|
|
Laitance |
A layer of weak material containing cement and fines from aggregates,
brought to the top of overwet concrete, the amount of which is generally
increased by overworking and over-manipulating concrete at the surface by
improper finishing. |
|
Layer |
See Course |
|
Lean Concrete |
Concrete of low cement content. |
|
Life-Cycle Cost Analysis |
The process used to compare projects based on their initial cost,
future cost and salvage value, which accounts for the time value of money. |
|
Lift |
The concrete placed between two consecutive horizontal construction
joints, usually consisting of several layers or courses. |
|
Liquid Sealant |
Sealant materials that install in liquid form and cool or cure to their
final properties; rely on long-term adhesion to the joint reservoir faces. |
|
Load Transfer Efficiency |
The ability of a joint or crack to transfer a portion of a load applied
on side of the joint or crack to the other side of the joint or crack. |
|
Load-Transfer Assembly |
Most commonly, the basket or carriage designed to support or link dowel
bars during concreting operations so as to hold them in place, in the
desired alignment. |
|
Longitudinal Broom |
Surface texture achieved in similar manner as transverse broom, except
that broom is pulled in a line parallel to the pavement centerline. |
|
Longitudinal Joint |
A joint parallel to the long dimension of a structure or pavement. |
|
Longitudinal Reinforcement |
Reinforcement essentially parallel to the long axis of a concrete
member or pavement. |
|
Longitudinal Tine |
Surface texture achieved by a hand held or mechanical device equipped
with a rake-like tining head that moves in a line parallel to the pavement
centerline. |
|
Lot |
A defined quantity. |
|
M |
|
|
Map Cracking |
1) Intersecting cracks that extend below the surface of hardened
concrete; caused by shrinkage of the drying surface concrete which is
restrained by concrete at greater depths where either little or no
shrinkage occurs; vary in width from fine and barely visible to open and
well-defined. 2) The chief symptom of chemical reaction between alkalis in
cement and mineral constituents in aggregate within hardened concrete; due
to differential rate of volume change in different portions of the
concrete; cracking is usually random and on a fairly large scale, and in
severe instances the cracks may reach a width of 0.50 in. See also
Checking, Crazing, and Pattern Cracking. |
|
Maximum Size Aggregate |
The largest size aggregate particles present in sufficient quantity to
affect properties of a concrete mixture. |
|
Membrane Curing |
A process that involves either liquid sealing compound (e.g.,
bituminous and paraffinic emulsions, coal tar cut-backs, pigmented and
non-pigmented resin suspensions, or suspensions of wax and drying oil) or
non-liquid protective coating (e.g., sheet plastics or
"waterproof" paper), both of which types function as films to
restrict evaporation of mixing water from the fresh concrete surface. |
|
Mesh |
The number of openings (including fractions thereof) per unit of length
in either a screen or sieve in which the openings are 6 mm or less. |
|
Mesh Reinforcement |
See Welded-Wire Fabric Reinforcement |
|
Method and Material Specification |
Specification that directs the contractor to use specified materials in
definite proportions and specific types of equipment and methods to place
the material. |
|
Mix |
The act or process of mixing; also mixture of materials, such as mortar
or concrete. |
|
Mix Design |
See Proportioning |
|
Mixer |
A machine used for blending the constituents of concrete, grout,
mortar, cement paste, or other mixture. |
|
Mixer, Batch |
See Batch Mixer |
|
Mixer, Horizontal Shaft |
A mixer having a stationary cylindrical mixing compartment, with the
axis of the cylinder horizontal, and one or more rotating shafts to which
mixing blades or paddles are attached; also called Pugmill. |
|
Mixer, Non-tilting |
A horizontally rotating drum mixer that charges, mixes, and discharges
without tilting. |
|
Mixer, Open-top |
A truck-mounted mixer consisting of a trough or a segment of a
cylindrical mixing compartment within which paddles or blades rotate about
the horizontal axis of the trough. See also Mixer, Horizontal Shaft. |
|
Mixer, Tilting |
A rotating drum mixer that discharges by tilting the drum about a fixed
or movable horizontal axis at right angles to the drum axis. The drum axis
may be horizontal or inclined while charging and mixing. |
|
Mixer, Transit |
See Truck Mixer |
|
Mixing Cycle |
The time taken for a complete cycle in a batch mixer; i.e., the time
elapsing between successive repetitions of the same operation (e.g.,
successive discharges of the mixer). |
|
Mixing Plant |
See Batch Plant |
|
Mixing Speed |
Rotation rate of a mixer drum or of the paddles in an open-top, pan, or
trough 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 |
The period during which the mixer is combining the ingredients for a
batch of concrete. For stationary mixers, the time is measured from the
completion of batching cement and aggregate until the beginning of
discharge. For truck mixers, mixing is given in term of the number of
revolutions of the drum at mixing speed. |
|
Mixing Water |
The water in freshly mixed sand-cement grout, mortar, or concrete,
exclusive of any previously absorbed by the aggregate (e.g., water
considered in the computation of the net water-cement ratio). See also
Batched Water and Surface Moisture. |
|
Mixture |
The assembled, blended, commingled ingredients of mortar, concrete, or
the like, or the proportions for their assembly. |
|
Modulus of Rupture |
A measure of the ultimate load-carrying capacity of a beam, sometimes
referred to as "rupture modulus" or "rupture
strength." It is calculated for apparent tensile stress in the
extreme fiber of a transverse test specimen under the load that produces
rupture. See also Flexural Strength. |
|
Moist |
Slightly damp but not quite dry to the touch; the term "wet"
implies visible free water, "damp" implies less wetness than
"wet," and "moist" implies not quite dry. See also
Damp and Wet. |
|
Moisture Barrier |
A vapor barrier. |
|
Moisture Content of Aggregate |
The ratio, expressed as a percentage, of the weight of water in a given
granular mass to the dry weight of the mass. |
|
Moisture-free |
The condition of a material that has been dried in air until there is
no further significant change in its mass. See also Mass and Overdry. |
|
Mortar |
Concrete with essentially no aggregate larger than about 3/16 inch. |
|
Mud Balls |
Balls of clay or silt ("mud"). |
|
Must-Grind Bump |
In a rideability specification, any bump exceeding a certain height in
25 feet (requirement may very between 0.3 and 0.5 in. bump height). |
|
N |
|
|
Natural Sand |
Sand resulting from natural disintegration and abrasion of rock. See
also Sand and Aggregate, Fine. |
|
NCHRP |
National Cooperative Highway Research Program |
|
Neat Cement Grout |
Grout consisting of portland cement and water. |
|
NHI |
National Highway Institute |
|
Nominal Maximum Size (of aggregate) |
In specifications for and descriptions of aggregate, the smallest sieve
opening through which the entire amount of the aggregate is permitted to
pass; sometimes referred to as "maximum size (of aggregate)." |
|
Non-agitating Unit |
A truck-mounted container for transporting central-mixed concrete that
is not equipped to provide agitation (slow mixing) during delivery. (Dump
truck) |
|
Non-air-entrained Concrete |
Concrete in which neither an air-entraining admixture nor an
air-entraining cement has been used. |
|
No-Slump Concrete |
Concrete with a slump of 6 mm or less. See also Zero-slump Concrete. |
|
NRMCA |
National Ready Mixed Concrete Association |
|
O |
|
|
Open-Graded Subbase |
Unstabilized layer consisting of crushed aggregates with a reduced
amount of fines to promote drainage. |
|
Ovendry |
The condition resulting from having been dried to essentially constant
weight, in an oven, at a temperature that has been fixed, usually between
221 and 239o F (105 and 115o C). |
|
Overlay |
The addition of a new material layer onto an existing pavement surface.
See also Resurfacing |
|
Overlay, Bonded |
See "Bonded Concrete Overlay." |
|
Overlay, Unbonded |
See "Unbonded Concrete Overlay." |
|
Overlay, UTW |
See "Ultra-thin Whitetopping" |
|
Overlay, Whitetopping |
See "Whitetopping" |
|
Over-Sanded |
Containing more sand than would be required for adequate workability
and satisfactory finishing characteristics. |
|
Over-Vibrated |
Concrete vibrated more than is necessary for good consolidation and
elimination of entrapped air. |
|
Over-Wet |
The consistency of concrete when it contains more mixing water and
hence is of greater slump than is necessary for ready consolidation. |
|
P |
|
|
Partial-Depth Patching |
Patches for restoring localized areas of surface deterioration; Usually
for compression spalling problems, severe scaling, or other surface
problems that are within the upper one-third of the slab depth. |
|
Partial-Depth Repair |
See "Partial-Depth Patching" |
|
Particle-Size Distribution |
The division of particles of a graded material among various sizes; for
concrete materials, usually expressed in terms of cumulative percentages
larger or smaller than each of a series of diameters or the percentages
within certain ranges of diameter, as determined by sieving. |
|
Paste |
Constituent of concrete consisting of cement and water. |
|
Pattern Cracking |
Fine openings on concrete surfaces in the form of a pattern; resulting
from a decrease in volume of the material near the surface, an increase in
volume of the material below the surface, or both. |
|
Pavement (concrete) |
A layer of concrete over such areas as roads, sidewalks, canals,
airfields, and those used for storage or parking. See also Rigid Pavement. |
|
Paving Train |
An assemblage of equipment designed to place and finish a concrete
pavement. |
|
PCA |
Portland Cement Association |
|
PCC |
Portland Cement Concrete |
|
Pea Gravel |
Screened gravel the particle sizes of which range between 3/16 and 3/8
inch in diameter. |
|
Percent Fines |
Amount, expressed as a percentage, of material in aggregate finer than
a given sieve, usually the No. 200 (75 m m) sieve; also, the amount of
fine aggregate in a concrete mixture expressed as a percent by absolute
volume of the total amount of aggregate. |
|
Performance-Based Specification |
Specification that describes the desired levels of fundamental
engineering properties (for example, resilient modulus and/or fatigue
properties) that are predictors of performance and appear in primary
prediction relationships (i.e., models that can be used to predict
pavement stress, distress, or performance from combinations of predictors
that represent traffic, environmental, roadbed, and structural
conditions.) |
|
Performance-Related Specification |
Specification that describes the desired levels of key materials and
construction quality characteristics that have been found to correlate
with fundamental engineering properties that predict performance. These
characteristics (for example, strength of concrete cores) are amenable to
acceptance testing at the time of construction. |
|
Permeable Subbase |
Layer consisting of crushed aggregates with a reduced amount of fines
to promote drainage and stabilized with Portland cement or bituminous
cement. |
|
Phasing |
The sequences used by a contractor to build elements of a project. |
|
Pie Tape |
Tape used to measure the circumference of the grinding head blades on
diamond grinding equipment. |
|
Pitting |
A localized disintegration taking the form of cavities at the surface
of concrete. |
|
Placement |
The process of placing and consolidating concrete; a quantity of
concrete placed and finished during a continuous operation; also
inappropriately referred to as Pouring. |
|
Placing |
The deposition, distribution, and consolidation of freshly mixed
concrete in the place where it is to harden; also inappropriately referred
to as Pouring. |
|
Plain Bar |
A reinforcing bar without surface deformations, or one having
deformations that do not conform to the applicable requirements. |
|
Plain Concrete |
Concrete without reinforcement. |
|
Plain Pavement |
Concrete pavement with relatively short joint spacing and without
dowels or reinforcement |
|
Plane of Weakness |
The plane along which a body under stress will tend to fracture; may
exist by design, by accident, or because of the nature of the structure
and its loading. |
|
Plastic |
A condition of freshly mixed concrete such that it is readily
remoldable and workable, cohesive, and has an ample content of cement and
fines, but is not over-wet. |
|
Plastic Consistency |
Condition of freshly mixed cement paste, mortar, or concrete such that
deformation will be sustained continuously in any direction without
rupture; in common usage, concrete with slump of 3 to 4 inches (80 to 100
mm). |
|
Plastic Cracking |
Cracking that occurs in the surface of fresh concrete soon after it is
placed and while it is still plastic. |
|
Plastic Deformation |
Deformation that does not disappear when the force causing the
deformation is removed. |
|
Plastic Shrinkage Cracking |
Cracks, usually parallel and only a few inches deep and several feet
long, in the surface(s) of concrete pavement that are the result of rapid
moisture loss through evaporation. |
|
Plasticity |
That property of fresh concrete or mortar which determines its
resistance to deformation or its ease of molding. |
|
Plasticizer |
A material that increases the plasticity of a fresh cement paste,
mortar, or concrete. |
|
Pneumatic |
Moved or worked by air pressure. |
|
Point Bearing |
Occurs when a partial-depth patch is made without the compressible
insert; also, slab expansion in hot weather forces an adjacent slab to
bear directly against a small partial-depth patch and causes the patch to
fail by delaminating and popping out of place. |
|
Popout |
Pit or crater in the surface of concrete resulting from cracking of the
mortar due to expansive forces associated with a particle of unsound
aggregate or a contaminating material, such as wood or glass. |
|
Porosity |
The ratio, usually expressed as a percentage, of the volume of voids in
a material to the total volume of the material, including voids. |
|
Portland Cement |
A commercial product which when mixed with water alone or in
combination with sand, stone, or similar materials, has the property of
combining with water, slowly, to form a hard solid mass. Physically,
portland cement is a finely pulverized clinker produced by burning
mixtures containing lime, iron, alumina, and silica at high temperature
and in definite proportions, and then intergrinding gypsum to give the
properties desired. |
|
Portland Cement Concrete |
A composite material that consists essentially of a binding medium
(Portland cement and water) within which are embedded particles or
fragments of aggregate, usually a combination of fine aggregate course
aggregate. |
|
Portland-Pozzolan Cement |
See Cement, portland-pozzolan |
|
Pozzolan |
A siliceous or siliceous and aluminous material, which in itself
possesses little or no cementitious value but will, in finely divided form
and in the presence of moisture, chemically react with calcium hydroxide
at ordinary temperatures to form compounds possessing cementitious
properties. |
|
Pozzolan-Cement Grout |
Common slab stabilization grout consisting of water, portland cement
and pozzolan; usually fly ash. |
|
Preformed Compression Seal |
Joint sealant that is manufactured ready for installation and is held
in a joint by lateral pressure exerted against the reservoir by the seal
after being compressed during installation. |
|
Preservation |
The process of maintaining a structure in its present condition and
arresting further deterioration. See also Rehabilitation, Repair, and
Restoration. |
|
Pressure-Relief |
Cut made in a concrete pavement to relieve compressive forces of
thermal expansion during hot weather. |
|
Process Control |
Those quality assurance actions and considerations necessary to assess
production and construction processes so as to control the level of
quality being produced in the end product. This includes sampling and
testing to monitor the process but usually does not include acceptance
sampling and testing. |
|
Profile Index |
Smoothness qualifying factor determined from profilograph trace.
Calculated by dividing the sum of the total counts above the blanking band
for each segment by the sum of the segment length. |
|
Profile Line |
On a profile trace, line drawn by hand on the field trace to average
out spikes and minor deviations caused by rocks, texturing, dirt or
transverse grooving. |
|
Project Scoping |
An early planning step in the development of a project where all
project requirements are defined and a plan is developed to address them. |
|
Proportioning |
Selection of proportions of ingredients for mortar or concrete to make
the most economical use of available materials to produce mortar or
concrete of the required properties. |
|
PSI |
1) Pounds per square inch; a measure of the compressive, tensile or
flexural strength of concrete as determined by appropriate test. 2) In
pavements, the Performance Serviceability Index. |
|
Pugmill |
A stationary mechanical mixer for blending cement and aggregate. |
|
Pumping |
The forceful displacement of a mixture of soil and water that occurs
under slab joints, cracks and pavement edges which are depressed and
released quickly by high-speed heavy vehicle loads; occurs when concrete
pavements are placed directly on fine-grained, plastic soils or erodible
subbase materials. |
|
Punchout |
In continuously reinforced concrete pavement, the area enclosed by two
closely spaced transverse cracks, a short longitudinal crack, and the edge
of the pavement or longitudinal joint, when exhibiting spalling,
shattering, or faulting. Also, area between Y cracks exhibiting this same
deterioration. |
|
Q |
|
|
QA/QC |
See, Quality Assurance/Quality Control |
|
Quality Assurance |
Planned and systematic actions by an owner or his representative to
provide confidence that a product or facility meet applicable standards of
good practice. This involves continued evaluation of design, plan and
specification development, contract advertisement and award, construction,
and maintenance, and the interactions of these activities. |
|
Quality Assurance/
Quality Control Specification |
Statistically based specification that is a combination of end result
and material and method specifications. The contractor is responsible for
quality control (process control), and the highway agency is responsible
for acceptance of the product. |
|
Quality Control |
Actions taken by a producer or contractor to provide control over what
is being done and what is being provided so that the applicable standards
of good practice for the work are followed. |
|
R |
|
|
Random Crack |
See Uncontrolled Crack |
|
Raveling |
Displacement of aggregate or paste near the slab surface from sawing;
normally indicates that concrete strength is too low for sawing. |
|
Reactive-Aggregate |
Aggregate containing certain silica or carbonate compounds that are
capable of reacting with alkalis in portland cement, in some cases
producing damaging expansion of concrete. |
|
Ready-Mixed Concrete |
Concrete manufactured for delivery to a purchaser in a plastic and
unhardened state. |
|
Rebar |
Abbreviation for "reinforcing bar." See Reinforcement. |
|
Rebound Hammer |
An apparatus that provides a rapid indication of the mechanical
properties of concrete based on the distance of rebound of a spring-driven
missile. |
|
Reconstruction |
The process of removing an existing pavement from its grade and
replacing it with a completely new pavement. |
|
Recycled Concrete |
Concrete that has been processed for use, usually as aggregate. |
|
Recycling |
The act of processing existing pavement material into usable material
for a layer within a new pavement structure |
|
Rehabilitation |
The process of repairing or modifying a structure to a desired useful
condition. See also Preservation, Repair, and Restoration. |
|
Reinforced Concrete |
Concrete containing adequate reinforcement (prestressed or not
prestressed) and designed on the assumption that the two materials act
together in resisting forces. |
|
Reinforcement |
Bars, wires, strands, and other slender members embedded in concrete in
such a manner that the reinforcement and the concrete act together in
resisting forces. |
|
Reinforcement, Transverse |
Reinforcement at right angles to the longitudinal reinforcement; may be
main or secondary reinforcement. |
|
Relative Humidity |
The ratio of the quantity of water vapor actually present to the amount
present in a saturated atmosphere at a given temperature; expressed as a
percentage. |
|
Release Agent |
Material used to prevent bonding of concrete to a surface. See also
Bond Breaker. |
|
Remoldability |
The readiness with which freshly mixed concrete responds to a remolding
effort, such as jigging or vibration, causing it to reshape its mass
around reinforcement and to conform to the shape of the form. See also
Flow. |
|
Repair |
To replace or correct deteriorated, damaged, or faulty materials,
components, or elements of a structure. See also Preservation,
Rehabilitation, and Restoration. |
|
Reservoir |
The part of a concrete joint that normally holds a sealant material.
Usually a widening saw cut above the initial saw cut. |
|
Restoration |
The process of reestablishing the materials, form, and appearance of a
structure to those of a particular era of the structure. See also
Preservation, Rehabilitation, and Repair. |
|
Resurfacing |
The addition of a new material layer onto an existing pavement surface
for the purposes of correcting a functional factor, such as smoothness or
texture |
|
Retardation |
Reduction in the rate of hardening or strength development of fresh
concrete, mortar, or grout; i.e., an increase in the time required to
reach initial and final set. |
|
Retarder |
An admixture that delays the setting of cement and hence of mixtures
such as mortar or concrete containing cement. |
|
Retempering |
Addition of water and remixing of concrete or mortar which has lost
enough workability to become unplaceable or unusable. See also Tempering. |
|
Retrofit Dowel Bars |
Dowels that install into slots cut into the surface of an existing
concrete pavement. |
|
Revibration |
A second vibration applied to fresh concrete, preferably as long after
the first vibration as the concrete will still respond properly. |
|
Rheology |
The science of dealing with flow of materials, including studies of
deformation of hardened concrete, the handling and placing of freshly
mixed concrete, and the behavior of slurries, pastes, and the like. |
|
Ribbon Loading |
Method of batching concrete in which the solid ingredients, and
sometimes the water, enter the mixer simultaneously. |
|
Rich Mixture |
A concrete mixture containing a large amount of cement. |
|
Rigid Pavement |
Pavement that will provide high bending resistance and distribute loads
to the foundation over a comparatively large area. |
|
Rock Pocket |
A portion of hardened concrete consisting of a concentration of coarse
aggregate that is deficient in mortar; caused by separation during
placement or insufficient consolidation, or both; see honeycomb. |
|
Rod |
A specified length of metal, circular in cross section with one end
rounded; used to compact concrete or mortar test specimens. |
|
Rod, Tamping |
A straight steel rod of circular cross section having one or both ends
rounded to a hemispherical tip. |
|
Rodability |
The susceptibility of fresh concrete or mortar to compaction by means
of a tamping rod. |
|
Rodding |
Compaction of concrete by means of a tamping rod. See also Rod,
Tamping, and Rodability. |
|
Rubblizing |
A destructive procedure to break existing concrete pavement in place to
fragments that range in size from 4 to 8 in. |
|
S |
|
|
Sack |
See Bag. |
|
Sample |
A group of units, or portion of material, taken from a larger
collection of units or quantity of material, which serves to provide
information that can be used as a basis for action on the larger quantity
or on the production process; the term is also used in the sense of a
sample of observations. |
|
Sampling, Continuous |
Sampling without interruptions throughout an operation or for a
predetermined time. |
|
Sampling, Intermittent |
Sampling successively for limited periods of time throughout an
operation or for a predetermined period of time. The duration of sample
periods and of the intervals between are not necessarily regular and are
not specified. |
|
Sand |
The fine granular material (usually less than 3/16 inch in diameter)
resulting from the natural disintegration of rock, or from the crushing of
friable sandstone. |
|
Sand Grout |
Grout mixture containing water, portland cement, and sand. |
|
Sand Streak |
A streak of exposed fine aggregate in the surface of formed concrete
caused by bleeding. |
|
Saturated Surface-Dry |
Condition of an aggregate particle or other porous solid when the
permeable voids are filled with water but there is no water on the exposed
surface. |
|
Saturated Surface-dry (SSD) Particle Density |
The mass of the saturated-surface-dry aggregate divided by its
displaced volume in water or in concrete. (Also called Bulk Specific
Gravity). |
|
Saturation |
1) In general, the condition of the coexistence in stable equilibrium
of either a vapor and a liquid or a vapor and solid phase of the same
substance at the same temperature. 2) As applied to aggregate or concrete,
the condition such that no more liquid can be held or placed within it. |
|
Saw Blade, Abrasive |
Concrete sawing medium that uses non-diamond abrasion elements. These
blades do not need water to cool, but water is sometimes used. |
|
Saw Blade, Diamond |
Concrete sawing medium that uses industrial diamonds as the primary
abrasion element. Blades are cooled with water to protect the host metal
from melting and prematurely dislodging the diamonds. |
|
Saw Cut |
A cut in hardened concrete utilizing diamond or silicone-carbide blades
or discs. |
|
Sawed Joint |
A joint cut in hardened concrete, generally not to the full depth of
the member, by means of special equipment. |
|
Sawing |
Cutting of joints in hardened concrete by means of special equipment
utilizing diamond or silicon carbide blades or discs; cut goes only part
way through the slab. |
|
Scaling |
Flaking or peeling away of the near-surface portion of hydraulic cement
concrete or mortar. |
|
Scallop |
Areas enclosed by profile line and blanking band. |
|
Schmidt Hammer (trade name), Swiss Hammer, or Rebound Hammer |
A device used to estimate the compressive strength of hardened concrete
by measuring surface hardness. |
|
Scoping |
See "Project Scoping" |
|
Screed |
1) To strike off concrete lying above the desired plane or shape. 2) A
tool for striking off the concrete surface, sometimes referred to as a
Strikeoff. |
|
Screed Guide |
Firmly established grade strips or side forms for unformed concrete
that will guide the strikeoff in producing the desired plane or shape. |
|
Screeding |
The operation of forming a surface by the use of screed guides and a
strikeoff. See also Strikeoff. |
|
Sealant |
See Joint Sealant and Membrane Curing |
|
Sealant Reservoir |
The saw kerf or formed slot in which a joint sealant is placed. Many
times this refers to a cut made to widen the original saw cut made for a
contraction joint. |
|
Sealing |
The process of filling the sawed joint with material to minimize
intrusion into the joint of water and incompressible materials. |
|
Sealing Compound |
See Joint Sealant and Membrane Curing |
|
Secondary Sawing |
The sawing that takes place to establish shape in the joint. Many times
this shape is the reservoir of the joint. |
|
Segregation |
The tendency, as concrete is caused to flow laterally, for coarse
aggregate and drier material to remain behind and for mortar and wetter
material to flow ahead. This also occurs in a vertical direction when wet
concrete is over-vibrated, the mortar and wetter material rising to the
top. In the vertical direction, segregation may also be called
Stratification. |
|
Semiautomatic Batcher |
A batcher equipped with gates or valves that are separately opened
manually to allow the material to be weighed but which are closed
automatically when the designated weight of each material has been
reached. |
|
Separation |
The tendency, as concrete is caused to pass from the unconfined ends of
chutes or conveyor belts, for coarse aggregate to separate from the
concrete and accumulate at one side; the tendency, as processed aggregate
leaves the ends of conveyor belts, chutes, or similar devices with
confining sides, for the larger aggregate to separate from the mass and
accumulate at one side; the tendency for solids to separate from the water
by gravitational settlement. See also Bleeding and Segregation. |
|
Set |
The condition reached by a cement paste, mortar, or concrete when it
has lost plasticity to an arbitrary degree, usually measured in terms of
resistance to penetration or deformation. Initial set refers to first
stiffening. Final set refers to attainment of significant rigidity. |
|
Set-accelerating Admixture |
See Accelerator |
|
Set-retarding Admixture |
See Retarder |
|
Setting of Cement |
Development of rigidity of cement paste, mortar, or concrete as a
result of hydration of the cement. The paste formed when cement is mixed
with water remains plastic for a short time. During this stage it is still
possible to disturb the material and remix without injury, but as the
reaction between the cement and water continues, the mass loses its
plasticity. This early period in the hardening is called the "setting
period," although there is not a well-defined break in the hardening
process. |
|
Setting Time |
The time required for a specimen of concrete, mortar or cement paste,
prepared and tested under standardized conditions, to attain a specified
degree of rigidity. |
|
Settlement |
Sinking of solid particles in grout, mortar, or fresh concrete, after
placement and before initial set. See also Bleeding. |
|
Settlement Shrinkage |
A reduction in volume of concrete prior to the final set of
cementitious mixtures; caused by settling of the solids and decreases in
volume due to the chemical combination of water with cement. See Plastic
Shrinkage. |
|
Shrinkage |
Decrease in length or volume. |
|
Shrinkage Crack |
Crack from restraint of volume reduction due to shrinkage or
temperature contraction; usually occurring within the first few days after
placement. |
|
Shrinkage Cracking |
Cracking of a slab due to failure in tension caused by external or
internal restraints as reduction in moisture content develops. |
|
Shrink-mixed Concrete |
Ready-mixed concrete mixed partially in a stationary mixer and then
mixed in a truck mixer. |
|
Sieve |
A metallic plate or sheet, a woven-wire cloth, or other similar device,
with regularly spaced apertures of uniform size, mounted in a suitable
frame or holder for use in separating granular material according to size. |
|
Sieve Analysis |
The classification of particles, particularly of aggregates, according
to sizes as determined with a series of sieves of different openings. |
|
Silicone |
A resin, characterized by water-repellent properties, in which the main
polymer chain consists of alternating silicon and oxygen atoms, with
carbon-containing side groups; silicones may be used in joint sealing
compounds, caulking or coating compounds, or admixtures for concrete. |
|
Silicone Sealant |
Liquid joint sealant consisting of silicone-based material. |
|
Skid Resistance |
A measure of the frictional characteristics of a surface. |
|
Slab Jacking |
Process of injecting grout materials beneath concrete slabs in order to
lift or elevate the slabs. |
|
Slab Stabilization |
Process of injecting grout materials beneath concrete slabs in order to
fill voids without raising the concrete slabs. |
|
Slip Form Paving |
A type of concrete paving process that involves extruding the concrete
through a machine to provide a uniform dimension of concrete paving. |
|
Slipform |
A form that is pulled or raised as concrete is placed; may move in a
generally horizontal direction to lay concrete evenly for highway paving
or on slopes and inverts of canals, tunnels, and siphons; or vertically to
form walls, bins, or silos. |
|
Slump |
A measure of consistency of freshly mixed concrete, equal to the
subsidence measured to the nearest 1/4-inch (6-mm) of the molded specimen
immediately after removal of the slump cone. |
|
Slump Cone |
A mold in the form of the lateral surface of the frustum of a cone with
a base diameter of 8 in (203 mm), top diameter 4 in (102 mm), and height
12 in (305 mm), used to fabricate a specimen of freshly mixed concrete for
the slump test. |
|
Slump Loss |
The amount by which the slump of freshly mixed concrete changes during
a period of time after an initial slump test was made on a sample or
samples thereof. |
|
Slump Test |
The procedure for measuring slump. |
|
Slurry |
Mixture of water and concrete particles resulting from concrete sawing
or grinding. |
|
Solid Volume |
See Absolute Volume |
|
Sounding |
Process of tapping concrete slab surface with metal object, listening
for tone from the impact, to determine areas of delamination. |
|
Soundness |
In the case of a cement, freedom from large expansion after setting. In
the case of aggregate, the ability to withstand aggressive conditions to
which concrete containing it might be exposed, particularly those due to
weather. |
|
Spalling, Compression |
Cracking, breaking, chipping, or fraying of slab edges within 0.6 meter
of a transverse joint. |
|
Spalling, Sliver |
Chipping of concrete edge along a joint sealant; usually within 12
millimeters of the joint edge. |
|
Spalling, Surface |
Cracking, breaking, chipping, or fraying of slab surface; usually
within a confined area less than 0.5 square meters. |
|
Specific Gravity |
The ratio of the weight in air of a given volume of material at a
stated temperature to the weight in air of an equal volume of distilled
water at the same temperature. |
|
Specific Gravity Factor |
The ratio of the weight of aggregates (including all moisture), as
introduced into the mixer, to the effective volume displaced by the
aggregates. |
|
Split Batch Charging |
Method of charging a mixer in which the solid ingredients do not all
enter the mixer together; cement, and sometimes different sizes of
aggregate, may be added separately. |
|
Spud Vibrator |
A vibrator used for consolidating concrete, having a vibrating casing
or head that is used by insertion into freshly placed concrete. |
|
Standard Deviation |
The root mean square deviation of individual values from their average. |
|
Static Load |
The weight of a single stationary body or the combined weights of all
stationary bodies in a structure (such as the load of a stationary vehicle
on a roadway); during construction, the combined weight of forms,
stringers, joists, reinforcing bars, and the actual concrete to be placed.
See also Dead Load. |
|
Stationary Hopper |
A container used to receive and temporarily store freshly mixed
concrete. |
|
Storage Hopper |
See Stationary Hopper |
|
Straight-Edging |
Process of using a rigid, straight piece of either wood or metal to
strike off or screed a concrete surface to proper grade or to check the
planeness of a finished surface. |
|
Stratification |
The separation of over-wet or over-vibrated concrete into horizontal
layers with increasingly lighter material toward the top; water, laitance,
mortar, and coarse aggregate will tend to occupy successively lower
positions (in that order). |
|
Strength |
A generic term for the ability of a material to resist strain or
rupture induced by external forces. See also Compressive Strength, Fatigue
Strength, Flexural Strength, Shear Strength, Splitting Tensile Strength,
Tensile Strength, Ultimate Strength, and Yield Strength. |
|
Stress |
Intensity of internal force (i.e., force per unit area) exerted by
either of two adjacent parts of a body on the other across an imagined
plane of separation; when the forces are parallel to the plane, the stress
is called shear stress; when the forces are normal to the plane the stress
is called normal stress; when the normal stress is directed toward the
part on which it acts it is called compressive stress; when it is directed
away from the part on which it acts it is called tensile stress. |
|
Strikeoff |
To remove concrete in excess of that required to fill the form evenly
or bring the surface to grade; performed with a straightedged piece of
wood or metal by means of a forward sawing movement or by a power operated
tool appropriate for this purpose; also the name applied to the tool. See
also Screed and Screeding. |
|
Structural Capacity |
Expression of the ability of a pavement to carry traffic loads;
Expressed as number of equivalent single axle loads in AASHTO design
methodology. |
|
Subbase |
A layer in a pavement system between the subgrade and base course or
between the subgrade and a portland cement concrete pavement. |
|
Subgrade |
The soil prepared and compacted to support a structure or a pavement
system. |
|
Sulfate Attack |
Chemical or physical reaction between certain constituents in cement
and sulfates in the soil or groundwater; sufficient attack may disrupt
concrete that is susceptible to it. |
|
Sulfate Resistance |
The ability of aggregate, cement paste, or mixtures thereof to
withstand chemical attack by sulfate ion in solution. |
|
Superplasticizer |
See Water-Reducing Admixture (high range) |
|
Supplementary Cementitious Material |
Mineral admixtures consisting of powdered or pulverized materials which
are added to concrete before or during mixing to improve or change some of
the plastic or hardened properties of Portland cement concrete. Materials
are generally natural or by-products of other manufacturing processes. |
|
Surface Moisture |
Water retained on surfaces of aggregates capable of mixing with
portland cement in concrete; distinguished from absorbed moisture, which
is contained inside the aggregate particles. |
|
Surface Retarder |
A retarder used by application to a form or to the surface of newly
placed concrete to delay setting of the cement to facilitate construction
joint cleanup or to facilitate production of exposed, aggregate finish. |
|
Surface Tension |
That property, due to molecular forces, that exists in the surface film
of all liquids and tends to prevent the liquid from spreading. |
|
Surface Texture |
Degree of roughness or irregularity of the exterior surfaces of
aggregate particles or hardened concrete. |
|
Surface Vibrator |
A vibrator used for consolidating concrete by application to the top
surface of a mass of freshly mixed concrete; four principal types exist:
vibrating screeds, pan vibrators, plate or grid vibratory tampers, and
vibratory roller screeds. |
|
Surface Voids |
Cavities visible on the surface of a solid. See also Bug Holes. |
|
Surface Water |
See Surface Moisture |
|
Swelling |
Increase in length or volume. See also Autogenous Volume Change,
Contraction, Expansion, and Volume Change. |
|
T |
|
|
Tamper |
1) An implement used to consolidate concrete or mortar in molds or
forms. 2) A hand-operated device for compacting floor topping or other
unformed concrete by impact from the dropped device in preparation for
strikeoff and finishing; contact surface often consists of a screen or a
grid of bars to force coarse aggregates below the surface to prevent
interference with floating or troweling. See also Jitterbug. |
|
Tamping |
The operation of compacting freshly placed concrete by repeated blows
or penetrations with a tamping device. |
|
Temper |
The addition of water and mixing of concrete or mortar as necessary to
bring it initially to the desired consistency. See also Retempering. |
|
Tensile Strength |
Maximum stress that a material is capable of resisting under axial
tensile loading based on the cross-sectional area of the specimen before
loading. |
|
Texturing |
The process of producing a special texture on either unhardened or
hardened concrete. |
|
Thermal Expansion |
Expansion caused by increase in temperature. |
|
Thermal Movement |
Change of dimension of concrete or masonry resulting from change of
temperatures. See also Contraction and Expansion. |
|
Thermal Shock |
The subjection of newly hardened concrete to a rapid change in
temperature which may be expected to have a potentially deleterious
effect. |
|
Tie Bar |
Bar at right angles to and tied to reinforcement to keep it in place;
bar extending across a construction joint. |
|
Tilting Concrete Mixer |
See Mixer, Tilting |
|
Time of Haul |
In production of ready-mixed concrete, the period from first contact
between mixing water and cement until completion of discharge of the
freshly mixed concrete. |
|
Time of Set |
Time required after addition of water to cement for cement paste,
mortars, or concretes to attain a certain arbitrary degree of hardness or
strength. |
|
Time of Setting |
See Initial Setting Time and Final Setting Time. |
|
TMMB |
Truck Mixer Manufacturers’ Bureau; most truck mixers carry TMMB
rating plates. |
|
Tongue and Groove |
A joint in which a protruding rib on the edge of one side fits into a
groove in the edge of the other side, abbreviated "T & G."
See also Keyway. |
|
Topping |
1) A layer of high quality concrete placed to form a floor surface on a
concrete base, or 2) a dry-shake application of a special material to
produce particular surface characteristics. |
|
Transit-mixed Concrete |
Concrete, the mixing of which is wholly or principally accomplished in
a truck mixer. (Same as truck mixed concrete.) |
|
Transverse Broom |
Surface texture obtained using either a hand broom or mechanical broom
that lightly drags the stiff bristles across the surface. |
|
Transverse Crack |
Crack that develops at a right angle to the long direction of the
member. |
|
Transverse Joint |
A joint normal to the longitudinal dimension of a structure. |
|
Transverse Reinforcement |
See Reinforcement, Transverse |
|
Transverse Tine |
Surface texture achieved by a hand held or mechanical device equipped
with a rake-like tining head that moves laterally across the width of the
paving surface. |
|
TRB |
Transportation Research Board |
|
Trial Batch |
A batch of concrete used for establishing or checking proportions. |
|
Trowel |
A flat, broad-bladed steel hand tool used in the final stages of
finishing operations to impart a relatively smooth surface to concrete
floors and other unformed concrete surfaces; also, a flat
triangular-bladed tool used for applying mortar to masonry. |
|
Truck mixed Concrete |
Concrete, the mixing of which is accomplished in a truck mixer. |
|
Truck Mixer |
A concrete mixer suitable for mounting on a truck chassis and capable
of mixing concrete in transit. See also Horizontal-Axis Mixer,
Inclined-Axis Mixer, and Agitator. |
|
U |
|
|
Ultra-thin Whitetopping |
Thin layer of new concrete (2-4 inches), usually high strength and
fiber-reinforced, placed over a prepared surface of distressed asphalt |
|
Unbonded Concrete Overlay |
Overlay of new concrete placed onto distressed existing concrete
pavement with a layer of asphalt or other medium between the new and old
concrete surface to separate them. |
|
Uncontrolled Crack |
A crack that is located within a slab away from the sawed joints. |
|
Under-Sanded |
A concrete mixture that is deficient in sand content; a condition
associated with poor workability or finishing characteristics. |
|
Unit Water Content |
The quantity of water per unit volume of freshly mixed concrete, often
expressed as pounds or gallons per cubic yard. It is the quantity of water
on which the water-cement ratio is based and does not include water
absorbed by the aggregate. |
|
Unit Weight |
See Bulk Density and Specific Gravity |
|
Unreinforced Concrete |
See Plain Concrete |
|
Unsound Aggregate |
An aggregate or individual particles of an aggregate capable of causing
or contributing to deterioration or disintegration of concrete under
anticipated conditions of service. |
|
Uplift Beam |
Beam-like movement detection device used to monitor slab lift during
slab stabilization. |
|
V |
|
|
Vibrated Concrete |
Concrete compacted by vibration during and after placing. |
|
Vibration |
Energetic agitation of concrete produced by a mechanical oscillating
device at moderately high frequency to assist consolidation and
compaction. |
|
Vibration Limit |
That time at which fresh concrete has hardened sufficiently to prevent
its becoming mobile when subject to vibration. |
|
Vibration, External |
External vibration employs vibrating devices attached at strategic
positions on the forms and is particularly applicable to manufacture of
precast items and for vibration of tunnel-lining forms; in manufacture of
concrete products, external vibration or impact may be applied to a
casting table. |
|
Vibration, Internal |
Internal vibration employs one or more vibrating elements that can be
inserted into the concrete at selected locations, and is more generally
applicable to in-place construction. |
|
Vibration, Surface |
Surface vibration employs a portable horizontal platform on which a
vibrating element is mounted. |
|
Vibrator |
An oscillating machine used to agitate fresh concrete so as to
eliminate gross voids, including entrapped air but no entrained air, and
produce intimate contact with form surfaces and embedded materials. |
|
Vibratory Plate Compactor |
Motorized, one-man tool consisting of a vibrating square plate that
transmits energy to compact granular materials. |
|
Volume Batching |
The measuring of the constituent materials for mortar or concrete by
volume. |
|
W |
|
|
Wash (or Flush) Water |
Water carried on a truck mixer in a special tank for flushing the
interior of the mixer after discharge of the concrete. |
|
Water-Cement Ratio |
The ratio of the amount of water, exclusive only of that absorbed by
the aggregates, to the amount of portland cement in a concrete or mortar
mixture; preferably stated as a decimal by weight. |
|
Water-Cementitious Ratio |
The ratio of the amount of water, exclusive only of that absorbed by
the aggregates, to the amount of portland cement and other cementitious
material (fly ash, pozzolan, etc.) in a concrete or mortar mixture;
preferably stated as a decimal by weight. |
|
Water-Gain |
See Bleeding |
|
Water-Reducing Admixture |
A material that either increases slump of freshly mixed mortar or
concrete without increasing water content or maintains a workability with
a reduced amount of water, the effect being due to factors other than air
entrainment; also known as water reducer. |
|
Water-Reducing Admixture (High Range) |
A water-reducing admixture capable of producing large water reduction
or great flowability without causing undue set retardation or entrainment
of air in mortar or concrete. |
|
Weathering |
Changes in color, texture, strength, chemical composition or other
properties of a natural or artificial material due to the action of the
weather. |
|
Weight Batching |
Measuring the constituent materials for mortar or concrete by weight. |
|
Welded-Wire Fabric Reinforcement |
Welded-wire fabric in either sheets or rolls, used to reinforce
concrete. |
|
Well-Graded Aggregate |
Aggregate having a particle size distribution that will produce maximum
density; i.e., minimum void space. |
|
Wet |
Covered with visible free moisture; not dry. See also Damp and Moist. |
|
Wet Process |
In the manufacture of cement, the process in which the raw materials
are ground, blended, mixed, and pumped while mixed with water; the wet
process is chosen where raw materials are extremely wet and sticky, which
would make drying before crushing and grinding difficult. |
|
Whitetopping |
Concrete overlay pavement placed on an existing asphalt pavement. |
|
Whitetopping, Conventional |
Overlay of new concrete, greater than 4 inches thick, placed onto
existing asphalt pavement with no particular steps taken to ensure bonding
or debonding. |
|
Whitetopping, Ultra-thin |
See "Ultra-thin Whitetopping" |
|
Wiggle Bolt |
Two-piece threaded bolt system used for tying lanes of concrete
pavement; usually consists of a female section that is cast into a
vertical slab face, and an angled male end which screws into the female
coupler. |
|
Wire Mesh |
See Welded Wire Fabric |
|
Workability |
That property of freshly mixed concrete or mortar which determines the
ease and homogeneity with which it can be mixed, placed, compacted, and
finished. |
|
Working Crack |
A crack in a concrete pavement slab that undergoes significant
deflection and thermal opening and closing movements; Typically oriented
transverse to the pavement centerline and near a non-functioning
transverse contraction joint. |
|
X |
|
|
Y |
|
|
Yield |
The volume of fresh concrete produced from a known quantity of
ingredients; the total weight of ingredients divided by the unit weight of
the freshly mixed concrete. |
|
Z |
|
|
Zero-Slump Concrete |
Concrete of stiff or extremely dry consistency showing no measurable
slump after removal of the slump cone. See also Slump and No-Slump
Concrete. |
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