pack, dry concrete or mortar mixtures deposited and consolidated by dry packing.
pack, warehouse see set, warehouse.
pack set see cement, sticky and set, warehouse.
packaged concrete, mortar, grout mixtures of dry ingredients in packages, requiring only the addition of water to produce concrete, mortar, or grout.
packer a device inserted into a hole in which grout is to be injected which acts to prevent return of the grout around the injection pipe; usually an expandable device actuated mechanically, hydraulically, or pneumatically.
packerhead process see process, packerhead.
packing, dry placing of zero-slump, or near zero-slump, concrete, mortar, or grout by ramming into a confined space.
paddle mixer see mixer, open-top (preferred term).
paint, cement a paint consisting generally of white portland cement and water, pigments, hydrated lime, water repellents, or hygroscopic salts.
paint, cold-water a paint in which the binder or vehicle portion is composed of latex, casein, glue, or some similar material dissolved or dispersed in water.
Palladiana see Berliner.
(1) a prefabricated form unit used in concrete joist floor construction; and
(2) a container that receives particles passing the finest sieve during mechanical analysis of granular materials.
pan mixer see mixer, vertical-shaft (preferred term).
1. a section of form sheathing that can be erected and stripped as a unit;
2. a concrete element that is relatively thin with respect to other dimensions and is bordered by joints or edges; and
3. a region of a suspended slab system bounded by column, beam, or wall centerlines. History
panel, drop the thickened structural portion of a flat slab in the area surrounding column, column capital, or bracket, to reduce the intensity of stresses.
panel, exterior in a flat slab, a panel having at least one edge that is not in common with another panel.
panel, ribbed a panel composed of a thin slab reinforced by a system of ribs in one or two directions, usually orthogonal.
panel, sandwich a prefabricated panel that is a layered composite, formed by attaching two thin facings to a thicker core, for example, a precast-concrete panel consisting of two layers of concrete separated by a nonstructural insulating core.
panel, solid a solid slab, usually of constant thickness.
panel strip see strip, panel.
parallel-wire unit a post-tensioning tendon composed of a number of wires or strands that are approximately parallel.
parapet the part of a wall that extends above the roof level; a low wall along the top of a dam.
parge to coat with plaster, particularly foundation walls and rough masonry. (See also back plastering.)
partial prestressing see prestressing, partial.
partial release see release, partial.
particle, colloidal an electrically charged particle, generally smaller than 0.1 mm, dispersed in a second continuous medium.
particle shape the form of a particle. [See also cubical piece (of aggregate), elongated piece (of aggregate), and flat piece (of aggregate).]
particle-size distribution see grading.
parting agent see agent, release.
pass layer of shotcrete placed in one movement over the area of operation.
paste see cement paste, neat.
paste, cement binder of concrete and mortar consisting essentially of cement, water, hydration products and any admixtures together with very finely divided materials included in the aggregates. (See also cement paste, neat.)
paste content proportional volume of cement paste in concrete, mortar, or the like, expressed as volume percent of the entire mixture. (See also cement paste, neat).
paste volume see paste content.
pat a specimen of neat cement paste, about 3 in. (76 mm) in diameter and ½ in. (13 mm) in thickness at the center and tapering to a thin edge, on a flat glass plate for indicating setting time.
path of prestressing force the locus of points defining the resultant effective prestress force in a concrete member.
pattern cracking see cracks, craze and cracking, map.
pattern cracks see cracks, craze and cracking, map.
patterned ashlar see masonry, ashlar.
pavement (concrete) a layer of concrete on such areas as roads, sidewalks, canals, playgrounds, and those used for storage or parking. (See also pavement, rigid.)
pavement, flexible 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 hydraulic cement in the case of rigid pavement. (See also pavement, rigid.)
pavement, pervious a pavement comprising material with sufficient continuous voids to allow water to pass from the surface to the underlying layers. History
pavement, rigid pavement that will provide high bending resistance and distribute loads to the foundation over a comparatively large area.
(1) a concrete mixer, usually mounted on crawler tracks, that mixes and places concrete pavement on the subgrade.
(2) Precast-concrete paving brick.
paving train an assemblage of equipment designed to place and finish a concrete pavement.
pea gravel see gravel, pea.
peak load the highest value for load in any test at which the form of the curve becomes nonlinear and substantially changes slope.
peak load strength strength computed using the peak load.
1) an upright compression member whose height does not exceed three times its average least dimension, such as a short pier or plinth used as the base for a column; or
2) the portion of an elevated water storage tank from the top of the foundation to the base of the water-containing portion. History
pedestal pile see pile, pedestal.
peeling a process in which thin flakes of mortar are broken away from a concrete surface, such as by deterioration or by adherence of surface mortar to forms as forms are removed.
pencil rod see rod, pencil.
penetration an opening through which pipe, conduit, or other item passes through a wall or floor.
penetration probe see probe, penetration.
penetration resistance see resistance, penetration.
percent fines the amount, expressed as a percentage, of material in aggregate finer than a given sieve, usually the 75 mm (No. 200); also the amount of fine aggregate in a concrete mixture expressed as a percent by absolute volume of the total amount of aggregate.
percentage of reinforcement the ratio of cross-sectional area of reinforcing steel to the effective cross-sectional area of a member, expressed as a percentage.
periclase a crystalline mineral, magnesia, MgO, the equivalent of which may be present in portland-cement clinker, portland cement, and other materials, such as open-hearth slags and certain basic refractories.
perimeter grouting see grouting, perimeter.
period, precuring see period, presteaming (preferred term).
period, presteaming in the manufacture of concrete products, the time between molding of a concrete product and start of the temperature-rise period.
period, soaking in high-pressure and low-pressure steam curing, the time during which the live steam supply to the kiln or autoclave is shut off and the concrete products are exposed to the residual heat and moisture.
period, temperature-rise the time interval during which the temperature of a concrete product rises at a controlled rate to the desired maximum in autoclave or atmospheric-pressure steam curing.
period at maximum temperature see maximum-temperature period.
perlite a volcanic glass having a perlitic structure, usually having a higher water content than obsidian; when expanded by heating, used as an insulating material and as a lightweight aggregate in concretes, mortars, and plasters.
perlitic structure a structure produced in a homogeneous material by contraction during cooling, and consisting of a system of irregular convolute and spheroidal cracks; generally confined to natural glass.
permanent form see form, permanent.
permanent set see set, permanent.
permeability to water, coefficient of the rate of discharge of water under laminar flow conditions through a unit cross-sectional area of a porous medium under a unit hydraulic gradient and standard temperature conditions, usually 20 C.
pervious concrete see concrete, pervious.
petrography the branch of petrology dealing with description and systematic classification of rocks aside from their geologic relations, mainly by laboratory methods, largely chemical and microscopical; also, loosely, petrology or lithology; also the techniques and knowledge of petrography applied to mortar, concrete, and the like.
petrology the science of rocks, treating of their origin, structure, composition, etc., from aspects and in all relations. (See also petrography.)
phenolic resin see resin, phenolic.
phi (f) factor see factor, strength reduction (preferred term).
Philleo factor see factor, Philleo.
photometer, flame an instrument used to determine elements (especially sodium and potassium in portland cement) by the color intensity of their unique flame spectra resulting from introducing a solution of a compound of the element into a flame. (Also known as flame spectrophotometer.)
(1) a slender isolated foundation member of either plain or reinforced concrete that is cast on end in the ground; or
(2) An isolated vertical masonry member whose horizontal dimension measured at right angles to its thickness is not less than three times its thickness nor greater than six times its thickness and whose height is less than five times its length. History
pier, drilled a concrete pier with or without a casing, cast in place in a hole previously bored in soil or rock. (See also pile, cast-in-place.)
pier cap a concrete element that transfers load from a column or pedestal to the top of one or more supporting piers. History
pigment a coloring matter, usually in the form of an insoluble fine powder.
pilaster column built with a wall, usually projecting beyond the wall.
pilaster face see face, pilaster.
pilaster side see side, pilaster.
pile a slender structural element that is driven, jetted, or otherwise embedded on end in the ground to support a load or compact the soil. (See also pile, composite.) History
pile, batter a pile installed at an angle to the vertical; a raking pile or raker pile.
pile, bored see pier, drilled.
pile, caisson a cast-in-place pile made by driving a tube, excavating it, and filling the cavity with concrete.
pile, cast-in-place a concrete pile concreted either with or without a casing in its permanent location, as distinguished from a precast pile. (See also pier, drilled and pile, precast.)
pile, composite a pile made up of different materials, usually concrete and wood, or steel fastened together end to end, to form a single pile.
pile, concrete see pile, cast-in-place and pile, precast.
pile, drilled see pier, drilled.
pile, friction a load-bearing pile that receives its principal vertical support from skin friction between the surface of the buried pile and the surrounding soil.
pile, pedestal a cast-in-place concrete pile constructed so that concrete is forced out into a widened bulb or pedestal shape at the foot of the pipe which forms the pile.
pile, pipe a steel cylinder, usually between 10 and 24 in. (250 and 600 mm) in diameter, generally driven with open ends to firm bearing and then excavated and filled with concrete.
pile, precast a reinforced pile manufactured in a casting plant or at the site but not in its final position. (See also pile, cast-in-place.)
pile, raking see pile, batter (preferred term).
pile, sheet a pile in the form of a plank driven in close contact or interlocking with others to provide a tight wall to resist the lateral pressure of water, adjacent earth, or other materials; may be tongued and grooved if made of timber or concrete and interlocking if made of metal.
pile, wing a bearing pile, usually of concrete, widened in the upper portion to form part of a sheet pile wall.
pile bent see bent, pile.
pile cap see cap, pile.
pipe column see column, pipe.
pipe pile see pile, pipe.
pipe, vent a small-diameter pipe used in concrete construction to permit escape of air in a structure being concreted or grouted.
pitting development of relatively small cavities in a surface; in concrete, localized disintegration, such as a popout; in steel, localized corrosion evident as minute cavities on the surface.
placeability see workability.
placement the process of placing and consolidating concrete; a quantity of concrete placed and finished during a continuous operation; inappropriately referred to as pouring.
placing the deposition, distribution, and consolidation of freshly mixed concrete in the place where it is to harden; inappropriately referred to as pouring.
plain bar see bar, plain.
plain concrete see concrete, plain.
plain masonry see masonry, plain.
plain pavement unreinforced concrete pavement. History
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.
1) a mixture consisting essentially of a cementitious material or materials, fine aggregate, and water that forms a plastic mass. When applied to a surface, the mixture adheres to it and subsequently hardens;
2) the placed and hardened mixture; or
3) the act of placing such material. (See also stucco.) History
plaster, neat plaster devoid of sand.
plaster mold see mold, plaster.
plaster of paris CaSO4Χ½ H2O; gypsum, from which three-quarters of the chemically bound water has been driven off by heating; when wetted it recombines with water and hardens quickly. (See also hemihydrate.)
plastic possessing plasticity, or possessing adequate plasticity. (See also plasticity.)
plastic cement see cement, plastic.
plastic centroid centroid of the resistance to load computed for the assumptions that the concrete is stressed uniformly to 85% of its design strength and the steel is stressed uniformly to its specified yield point.
plastic consistency see consistency, plastic.
plastic deformation see deformation, inelastic.
plastic flow obsolete term for creep and stress relation. (See also creep; flow, plastic; and stress relaxation.)
plastic hinge see hinge, plastic.
plastic loss see creep.
plastic mortar see mortar, plastic.
plastic or bond fire clay a fire clay of sufficient natural plasticity to bond nonplastic material; a fire clay used as a plasticizing agent in mortar.
plastic shrinkage see shrinkage, plastic.
plastic-shrinkage crack see crack, plastic-shrinkage.
plasticity a complex property of a material involving a combination of qualities of mobility and magnitude of yield value; the property of freshly mixed cement paste, concrete, or mortar that determines its resistance to deformation or ease of molding.
plasticity index (PI) see index, plasticity (PI).
plasticize to produce plasticity or to render plastic.
plasticizer (1) a material that increases the plasticity of a fresh cementitious mixture; or (2) a substance added to a material to improve the materials flexibility. History
plate (1) in formwork for concrete: a flat, horizontal member either at the top or bottom, or both, of studs or posts; a mud sill if on the ground (see also mud sill); and
(2) in structural design: a member, the depth of which is substantially less than its length and width. (See also plate, flat and load-transfer assembly.)
plate, deformed a flat piece of metal, thicker than 1/4 in. (6 mm), having horizontal deformations or corrugations; used in construction to form a vertical joint and provide a mechanical interlock between adjacent sections.
plate, flat a flat slab without column capitals or drop panels. (See also slab, flat.)
plate, folded (1) a framing assembly composed of sloping slabs in a hipped or gabled arrangement; and
(2) prismatic shell with open polygonal section.
plum a large random-shaped stone dropped into freshly placed mass concrete to economize on the amount of the other concrete ingredients. (See also concrete, cyclopean.)
plumb vertical or to make vertical.
pneumatic feed see feed, pneumatic.
pneumatically applied mortar see shotcrete.
point count method method for determination of the volumetric composition of a solid by observation of the frequency with which areas of each component coincide with a regular system of points in one or more planes intersecting a sample of the solid. (See also linear-traverse method.)
point count method (modified) the point count method supplemented by a determination of the frequency with which areas of each component of a solid are intersected by regularly spaced lines in one or more planes intersecting a sample of the solid.
point load see load, point.
point of contraflexure see point of inflection (preferred term).
point of inflection the point on the length of a structural member subjected to flexure where the curvature changes from concave to convex or conversely and at which the bending moment is zero; also called point of contraflexure.
Poissons ratio see ratio, Poissons.
polarizing microscope see microscope, polarizing.
pole shore see shore, post.
polish or final grind the final operation in which fine abrasives are used to hone a surface to its desired smoothness and appearance.
polyester one of a large group of synthetic resins, mainly produced by reaction of dibasic acids with dihydroxy alcohols; commonly prepared for application by mixing with a vinyl-group monomer and free-radical catalysts at ambient temperatures and used as binders for resin mortars and concretes, fiber laminates (mainly glass), adhesives, and the like. (See also concrete, polymer.)
polyethylene a thermoplastic high-molecular-weight organic compound used in formulating protective coatings or, in sheet form, as a protective cover for concrete surfaces during the curing period, or to provide a temporary enclosure for construction operations.
polymer the product of polymerization; more commonly a rubber or resin consisting of large molecules formed by polymerization.
polymer concrete see concrete, polymer.
polymer-cement concrete see concrete, polymer-cement.
polymer-impregnated concrete see concrete, polymer-impregnated.
polymerization the reaction in which two or more molecules of the same substance combine to form a compound containing the same elements and in the same proportions but of higher molecular weight.
polystyrene resin see resin, polystyrene.
polysulfide coating see coating, polysulfide.
polyurethane reaction product of an isocyanate with any of a wide variety of other compounds containing an active hydrogen group; used to formulate tough, abrasion-resistant coatings.
polyvinyl acetate colorless, permanently thermoplastic resin; usually supplied as an emulsion or water-dispersible powder characterized by flexibility, stability towards light, transparency to ultraviolet rays, high dielectric strength, toughness, and hardness; the higher the degree of polymerization, the higher the softening temperature; may be used in paints for concrete.
polyvinyl chloride a synthetic resin prepared by the polymerization of vinyl chloride, used in the manufacture of nonmetallic waterstops for concrete.
ponding the creation and maintaining of a shallow pond of water on the surface of a concrete slab to assist curing; accidental or incidental occurrence of a shallow pond or ponds on a nominally flat surface of concrete; a condition in which a horizontal slab deforms downward between supports .
popcorn concrete see concrete, popcorn.
popout the breaking away of small portions of a concrete, mortar, and plaster surface due to localized internal pressure that leaves a shallow, typically conical, depression. History
porosity the ratio, usually expressed as a percentage of the volume of voids in a material to the total volume of the material including the voids.
portland blast-furnace slag cement see cement, portland blast-furnace slag.
portland cement see cement, portland.
portland-cement clinker see clinker, portland-cement.
portland-cement concrete see concrete.
portland-pozzolan cement see cement, portland-pozzolan.
portlandite a mineral; calcium hydroxide (Ca(OH)2); occurs naturally in Ireland; equivalent to a product of hydration of portland cement.
porous fill see drainage fill.
positive displacement wet-mix shotcrete delivery equipment in which a pump or other nonpneumatic means pumps the material through the delivery hose in a solid mass. History
positive moment see moment, positive.
positive reinforcement see reinforcement, positive.
post vertical formwork member used as a support ; also known as shore, prop, or jack.
post shore see shore, post.
post-tensioning method of prestressing in which prestressing steel is tensioned after concrete has hardened. History
post-tensioning, bonded post-tensioned construction in which the annular spaces around the tendons are grouted after stressing, thereby bonding the tendon to the concrete section.
pot life time interval after preparation during which a liquid or plastic mixture is to be used.
pouring (of concrete) see placement and placing.
power float see float, rotary (preferred term).
Powers spacing factor see factor, Powers spacing (preferred term).
pozzolan a siliceous or siliceous and aluminous material that in itself possesses little or no cementitious value but that will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties; there are both natural and artificial pozzolans.
pozzolan, artificial materials such as fly ash and silica fume. (See also fly ash, and silica fume).
pozzolan, natural a raw or calcined natural material that has pozzolanic properties (for example, volcanic tuffs or pumicites, opaline cherts and shales, clays, and diatomaceous earths).
pozzolanic of or pertaining to a pozzolan.
pozzolanic-activity index see index, pozzolanic-activity.
pozzolanic reaction see pozzolan.
preblended grout see grout, preblended.
precast a concrete member that is cast and cured in other than its final position; the process of placing and finishing precast concrete. (See also cast-in-place.)
precast concrete see concrete, precast.
precast pile see pile, precast.
precompressed zone see zone, precompressed.
precuring period see period, presteaming (preferred term).
prefire to raise the temperature of refractory concrete under controlled conditions before placing it in service.
preformed foam see foam, preformed.
premature stiffening see set, false and set, flash.
prepacked concrete see concrete, preplaced-aggregate.
preplaced-aggregate concrete see concrete, preplaced-aggregate and concrete, colloidal.
pre-post-tensioning a method of fabricating prestressed concrete in which some of the tendons are pretensioned and a portion of the tendons are post-tensioned.
preservation the process of maintaining a structure in its present condition and arresting further deterioration. (See also rehabilitation, repair, and restoration).
preset period see period, presteaming (preferred term).
preshrunk concrete (mortar, grout) see concrete (mortar, grout), preshrunk.
pressed edge see edge, pressed.
pressure, form lateral pressure acting on vertical or inclined formed surfaces, resulting from the fluid-like behavior of the unhardened concrete confined by the forms.
pressure, lateral see pressure, form.
presteaming period see period, presteaming.
prestress to place a hardened-concrete member or an assembly of units in a state of compression before application of service loads; the stress developed by prestressing, such as by pretensioning or post-tensioning. (See also concrete, prestressed; steel, prestressing; pretensioning; and post-tensioning.)
prestress, effective the prestressing force at a specific location in a prestressed-concrete member under the effects of service dead load or total service load after losses of prestress have occurred.
prestress, final see stress, final.
prestress, initial the prestressing stress (or force) applied to the concrete at the time of stressing.
prestress, transverse prestress that is applied at right angles to the longitudinal axis of a member or slab.
prestressed concrete see concrete, prestressed.
prestressing, nonsimultaneous the post-tensioning of tendons individually rather than simultaneously.
prestressing, partial prestressing to a stress level such that, under design loads, tensile stresses exist in the precompressed tensile zone of the prestressed member.
prestressing steel see steel, prestressing.
pretensioning a method of prestressing reinforced concrete in which the tendons are tensioned before the concrete has hardened.
pretensioning bed (or bench) the casting bed on which pretensioned members are manufactured and which resists the pretensioning force prior to release.
primary crusher see crusher, primary.
primary nuclear vessel interior container in a nuclear reactor designed for sustained loads and for working conditions.
principal planes see stress, principal.
principal stress see stress, principal.
probabilistic design see design, probabilistic.
probe, penetration a device for obtaining a measure of the resistance of concrete to penetration; customarily determined by the distance that a steel pin is driven into the concrete from a special gun by a precisely measured explosive charge.
process, centrifugal a process for producing concrete products, such as pipe, that uses an outer form that is rotated about a horizontal axis and into which concrete is fed by a conveyor, also called spinning process. (See also concrete, centrifugally cast; process, dry-cast; process, packerhead; process, tamp; and process, wet-cast.)
process, dry in the manufacture of cement, the process in which the raw materials are ground, conveyed, blended, and stored in a dry condition. (See also process, wet.)
process, dry-cast a process for producing concrete products, such as pipe, using low-frequency high-amplitude vibration to consolidate dry-mix concrete in the form. (See also centrifugal process; process, packerhead; tamp process; process, wet-cast.)
process, dry-tamp see packing, dry.
process, packerhead a process for producing concrete pipe that uses a rotating device that forms the interior surface of the pipe as concrete is fed into the form from above. (See also centrifugal process; process, dry-cast; tamp process; process, wet-cast.)
process, tamp a process for producing concrete products, such as pipe, that uses direct mechanical action to consolidate the concrete by the action of tampers that rise automatically as the form is rotated and filled with concrete from above. (See also process, centrifugal; process, dry-cast; process, packerhead; and process, wet-cast.)
process, wet-cast a process for producing concrete items, such as pipe, that uses concrete having a measurable slump, generally placed from above, and consolidated by vibration. (See also centrifugal process; process, dry-cast; process, packerhead; and tamp process.)
process, wet 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. (See also process, dry.)
promoter, flow substance added to coating to enhance brushability, flow, and leveling.
proof stress see stress, proof.
proportional limit see limit, proportional.
proportion to select proportions of ingredients to make the most economical use of available materials to produce mortar or concrete of the required properties. (See also mixture.)
protected paste volume the portion of hardened cement paste that is protected from the effects of freezing by proximity to an entrained air void. (See also factor, Philleo and factor, spacing.)
protection period the required time during which the concrete is maintained at or above a specific temperature to prevent freezing of the concrete or ensure the necessary strength of development.
proving ring see ring, proving.
psychrometer, sling a psychrometer containing independently matched dry- and wet-bulb thermometers, suitably mounted for manually swinging through the ambient air, to simultaneously indicate dry- and wet-bulb temperatures.
pugmill see mixer, horizontal-shaft (preferred term).
pulse velocity see velocity, pulse.
pulverized-fuel ash (pfa) see fly ash (preferred term in USA, pulverized-fuel ash is used in United Kingdom).
pumice a highly porous and vesicular lava usually of relatively high silica content composed largely of glass drawn into approximately parallel or loosely entwined fibers, which themselves contain sealed vesicles.
pumicite naturally occurring finely divided pumice and glass shards.
pump, concrete an apparatus that forces concrete to the placing position through a pipeline or hose.
pumped concrete see concrete, pumped.
pumping (of pavements) the ejection of water, or water and solid materials, such as clay or silt, along transverse or longitudinal joints and cracks, and along pavement edges caused by downward slab movement activated by the passage of loads over the pavement after the accumulation of free water on or in the base course, subgrade, or subbase.
punching shear failure of a base or slab when a heavily loaded column punches a hole through it.
punching shear stress shear stress calculated by diving the load on the slab that is transferred to the column by the product of the perimeter and the thickness of the base or cap or by the product of the perimeter taken at 1/2 the slab thickness away from the column and the thickness of the base or cap.
punning an obsolete term designating a light form of ramming. (See also ramming and tamping.)
purlin in roofs, a horizontal member supporting the common rafters. (See also beam.)
putty a plaster composed of quicklime or hydrated lime and water with or without plaster of paris or sand.
pyrite a mineral, iron disulfide (FeS2), that, if it occurs in aggregate used in concrete, can cause popouts and dark brown or orange-colored staining.
pycnometer a vessel for determination of specific gravity of liquids or solids.
pyrometric cone see cone, pyrometric.
pyrometric-cone equivalent (PCE) the number of that cone whose tip would touch the supporting plaque simultaneously with that of a cone of the refractory material being investigated when tested in accordance with a specified procedure such as ASTM C24.
|
|