Copy of `ACPA - American Pavement Glossary`
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ACPA - American Pavement Glossary
Category: Architecture and Buildings > concrete terms
Date & country: 25/09/2008, USA Words: 597
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PneumaticMoved or worked by air pressure.
Point BearingOccurs 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.
PopoutPit 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.
PorosityThe ratio, usually expressed as a percentage, of the volume of voids in a material to the total volume of the material, including voids.
Portland CementA 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 ...
Portland Cement ConcreteA 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 CementSee Cement, portland-pozzolan
PozzolanA 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 GroutCommon slab stabilization grout consisting of water, portland cement and pozzolan; usually fly ash.
Preformed Compression SealJoint 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.
PreservationThe process of maintaining a structure in its present condition and arresting further deterioration. See also Rehabilitation, Repair, and Restoration.
Pressure-ReliefCut made in a concrete pavement to relieve compressive forces of thermal expansion during hot weather.
Profile IndexSmoothness 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 LineOn 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 ScopingAn early planning step in the development of a project where all project requirements are defined and a plan is developed to address them.
ProportioningSelection 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.
PSI1) 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.
PugmillA stationary mechanical mixer for blending cement and aggregate.
PumpingThe 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.
PunchoutIn 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.
QA/QCSee, Quality Assurance/Quality Control
Quality AssurancePlanned 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 SpecificationStatistically 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 ControlActions 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.
Random CrackSee Uncontrolled Crack
RavelingDisplacement of aggregate or paste near the slab surface from sawing; normally indicates that concrete strength is too low for sawing.
Radius of Relative StiffnessA character or property of a concrete slab which measures the stiffness of the slab in relation to that of the subgrade; it is expressed by the equation
Reactive-AggregateAggregate 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 ConcreteConcrete manufactured for delivery to a purchaser in a plastic and unhardened state.
RebarAbbreviation for 'reinforcing bar.' See Reinforcement.
Rebound HammerAn apparatus that provides a rapid indication of the mechanical properties of concrete based on the distance of rebound of a spring-driven missile.
ReconstructionThe process of removing an existing pavement from its grade and replacing it with a completely new pavement.
Recycled ConcreteConcrete that has been processed for use, usually as aggregate.
RecyclingThe act of processing existing pavement material into usable material for a layer within a new pavement structure
RehabilitationThe process of repairing or modifying a structure to a desired useful condition. See also Preservation, Repair, and Restoration.
Reinforced ConcreteConcrete containing adequate reinforcement (prestressed or not prestressed) and designed on the assumption that the two materials act together in resisting forces.
ReinforcementBars, 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, TransverseReinforcement at right angles to the longitudinal reinforcement; may be main or secondary reinforcement.
Relative HumidityThe 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 AgentMaterial used to prevent bonding of concrete to a surface. See also Bond Breaker.
RemoldabilityThe 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.
SackSee Bag.
SampleA 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, ContinuousSampling without interruptions throughout an operation or for a predetermined time.
Sampling, IntermittentSampling 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.
SandThe 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 GroutGrout mixture containing water, portland cement, and sand.
Sand StreakA streak of exposed fine aggregate in the surface of formed concrete caused by bleeding.
Saturated Surface-DryCondition 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.
Saturation1) 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, AbrasiveConcrete sawing medium that uses non-diamond abrasion elements. These blades do not need water to cool, but water is sometimes used.
Saw Blade, DiamondConcrete 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 CutA cut in hardened concrete utilizing diamond or silicone-carbide blades or discs.
Sawed JointA joint cut in hardened concrete, generally not to the full depth of the member, by means of special equipment.
SawingCutting 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.
ScalingFlaking or peeling away of the near-surface portion of hydraulic cement concrete or mortar.
ScallopAreas enclosed by profile line and blanking band.
Schmidt HammerA device used to estimate the compressive strength of hardened concrete by measuring surface hardness.
ScopingSee 'Project Scoping'
Screed1) 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 GuideFirmly established grade strips or side forms for unformed concrete that will guide the strikeoff in producing the desired plane or shape.
ScreedingThe operation of forming a surface by the use of screed guides and a strikeoff. See also Strikeoff.
SealantSee Joint Sealant and Membrane Curing
Sealant ReservoirThe 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.
SealingThe process of filling the sawed joint with material to minimize intrusion into the joint of water and incompressible materials.
Sealing CompoundSee Joint Sealant and Membrane Curing
Secondary SawingThe sawing that takes place to establish shape in the joint. Many times this shape is the reservoir of the joint.
SegregationThe 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 BatcherA 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.
SeparationThe 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...
SetThe 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 AdmixtureSee Accelerator
Set-retarding AdmixtureSee Retarder
Setting of CementDevelopment 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 i...
Setting TimeThe time required for a specimen of concrete, mortar or cement paste, prepared and tested under standardized conditions, to attain a specified degree of rigidity.
SettlementSinking of solid particles in grout, mortar, or fresh concrete, after placement and before initial set. See also Bleeding.
Settlement ShrinkageA 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.
ShrinkageDecrease in length or volume.
Shrinkage CrackCrack from restraint of volume reduction due to shrinkage or temperature contraction; usually occurring within the first few days after placement.
Shrinkage CrackingCracking of a slab due to failure in tension caused by external or internal restraints as reduction in moisture content develops.
Shrink-mixed ConcreteReady-mixed concrete mixed partially in a stationary mixer and then mixed in a truck mixer.
SieveA 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 AnalysisThe classification of particles, particularly of aggregates, according to sizes as determined with a series of sieves of different openings.
SiliconeA 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 SealantLiquid joint sealant consisting of silicone-based material.
Skid ResistanceA measure of the frictional characteristics of a surface.
Slab JackingProcess of injecting grout materials beneath concrete slabs in order to lift or elevate the slabs.
Slab StabilizationProcess of injecting grout materials beneath concrete slabs in order to fill voids without raising the concrete slabs.
Slip Form PavingA type of concrete paving process that involves extruding the concrete through a machine to provide a uniform dimension of concrete paving.
SlipformA 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.
SlumpA 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 ConeA 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 LossThe 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 TestThe procedure for measuring slump.
SlurryMixture of water and concrete particles resulting from concrete sawing or grinding.
Solid VolumeSee Absolute Volume
SoundingProcess of tapping concrete slab surface with metal object, listening for tone from the impact, to determine areas of delamination.
SoundnessIn 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, CompressionCracking, breaking, chipping, or fraying of slab edges within 0.6 meter of a transverse joint.
Spalling, SliverChipping of concrete edge along a joint sealant; usually within 12 millimeters of the joint edge.