DICTIONARY OFARCHITECTURE &CONSTRUCTION2300 illustrationsFourth EditionEdited byCyril M. HarrisProfessor Emeritus of ArchitectureGraduate School of Architecture, Planning, and PreservationColumbia UniversityMcGraw-HillNew York Chicago San Francisco Lisbon LondonMadrid Mexico City Milan New Delhi San JuanSeoul Singapore Sydney Toronto
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This book is dedicated to the memory of Adolph K. Placzek,Avery Librarian at Columbia University, whose leadershipmade Avery Library one of the world’s greatest collectionson architecture. I am grateful to him for long and fruitfuldiscussions, for his exemplary scholarship, and for thegenerosity of spirit with which he shared his experience, hiswisdom, and the gift of his friendship.
xAssociation; Illuminating Engineering Society; National Builder’s Hardware Association;and American Concrete Institute (ACI) and ACI Committees. Further reproductionrequires permission from the above organizations. Certain other organizations andpublications have authorized reproduction of definitions or illustrations without formalacknowledgment. I thank William A. Pierson for permission to reproduce his photographof Round Arch style.I acknowledge the help of and thank Cary Sullivan, senior editor for architecture, design,and construction books, McGraw-Hill Professional. At International Typesetting and Com-position, whose task it was to work with the publisher to move the Dictionary from manuscriptto printed book, I thank Mona Tiwary for her exemplary diligence.
abat-voix In a church, a sound reflector behindand over a pulpit.a web between, so that two cells are formedwhen the block is laid in a wall.Abney level A hand level used for measuringvertical angles; comprised of a small telescope,bubble tube, and graduated vertical arc.above-grade building volume The volumeof a building (in cubic feet or in cubic meters)measured from the average adjoining grade levelto the average roof level, and from outside tooutside of exterior walls, but not includingbreezeways, porches, or terraces.abrade To wear away or scrape off a surface,especially by friction.Abrams’ law A statement applying to givenconcrete materials and conditions of test: For amixture of workable consistency, the strength ofconcrete provided by the mixture is determinedby the ratio of the amount of water to theamount of cement.abrasion A surface discontinuity caused byroughening or scratching.abrasion resistance The ability of a surfaceto resist being worn away or to maintain its orig-inal appearance when rubbed with anotherobject.abrasion resistance index A measure of theabrasion resistance of a vulcanized material orsynthetic rubber compound relative to that ofa standard rubber compound under specifiedconditions.abrasive A hard substance for removing mate-rial by grinding, lapping, honing, and polish-ing. Common abrasives include silicon carbide,boron carbide, diamond, emery, garnet, quartz,tripoli, pumice, diatomite, metal shot, grit, andvarious sands; usually adhered to paper orcloth.abraum A red ocher used to stain mahogany.abreuvoir In masonry, a joint or intersticebetween stones, to be filled with mortar orcement.ABS Abbr. for acrylonitrile-butadiene-styrene.abscissa In the plane Cartesian coordinate sys-tem, the horizontal coordinate of a point on aplane; the x-coordinate, obtained by measuringthe distance from the point to the y-axis along aline parallel to the x-axis.abat-voix2abat-voixabbey A monastery or convent; particularly thechurch thereof.abbey: Plan of abbey of St. Germain-des-Prés, Paris, 13thcent. A, church; B, cloister; C, city gate; E, chapter house;F, chapel; G, refectory; H, cellars and presses; I, abbot’s lodg-ing; K, ditches; L, gardensabbreuvoir Same as abreuvoir.ABC 1. Abbr. for “aggregate base course.”2. Abbr. for “Associated Builders and Con-tractors.”A-block A hollow, concrete masonry unit withone end closed and the opposite end open, having
abside Same as apse.absidiole Same as apsidiole.absolute humidity The mass of water vaporper unit volume of air.absolute pressure The sum of the gauge pres-sure plus atmospheric pressure.absolute volume 1.Of a granular material, thetotal volume of the particles, including the perme-able and impermeable voids, but excluding thespaces between the particles. 2.Of fluid, the vol-ume which the fluid occupies. 3.The displacementvolume of an ingredient of concrete or mortar.absorbed moisture Moisture that has entereda solid material by absorption and has physicalproperties not substantially different from ordi-nary water at the same temperature and pressure.Also see absorption.absorbency The property of a material thatmeasures its capacity to soak up liquids.absorbent A material which, owing to an affin-ity for certain substances, extracts one or moresuch substances from a liquid or gas with whichit is in contact, and which changes physically orchemically, or both, during the process.absorber 1.A device containing liquid for absorb-ing refrigerant vapor or other vapors. 2.In anabsorption system, that part of the low-pressureside of the system which is used for absorbing refrig-erant vapor. 3.That part of a solar collector whoseprimary function is to absorb radiant solar energy.absorber plate Same as solar collector.absorbing well, dry well, waste well Awell used for draining off surface water and con-ducting it underground, where it is absorbed.absorptance In illumination engineering, theratio of the absorbed flux to the incident flux.absorption 1.The process by which a liquid, or amixture of gases and liquid, is drawn into and tendsto fill permeable pores in a porous solid material;usually accompanied by a physical change, chemi-cal change, or both, of the material. 2.Theincrease in weight of a porous solid body resultingfrom the penetration of liquid into its permeablepores. 3.The increase in weight of a brick or tileunit when immersed in either cold or boiling waterfor a stated length of time; expressed as a percent-age of the weight of the dry unit. 4.The process bywhich radiant energy, which is incident on asurface, is converted to other forms of energy.5. See sound absorption. 6. See light absorption.absorption bed A pit of relatively largedimensions which is filled with coarse aggregateand contains a distribution pipe system; used toabsorb the effluent of a septic tank.absorption coefficient See sound absorptioncoefficient.absorption field, disposal field A system oftrenches containing coarse aggregate and distri-bution pipes through which septic-tank effluentmay seep into the surrounding soil.absorption field3absorption field composed of absorption trenchesExtent of coarse aggregate indicated by shaded areaabscissa: P, any point; NP, abscissa
absorption rate, initial rate of absorptionThe weight of water absorbed when a brick is par-tially immersed for one minute; usually expressedin grams per minute or ounces per minute.absorption system A refrigeration system inwhich the refrigerant gas evolved in the evapo-rator is taken up in an absorber and (upon theapplication of heat) released in a generator.absorption trench A trench containing coarseaggregate and a distribution tile pipe throughwhich septic-tank effluent may flow, coveredwith earth.abutment piece See solepiece.abuttals Those boundaries of one piece of landthat abut on adjacent pieces.abutting joint A joint between two pieces ofwood, in which the direction of the grain in onepiece is at an angle (usually 90°) to the grain inthe other.abutting tenon One of two tenons which areinserted in a common mortise from oppositesides, so as to touch each other.ac, a-c, a.c. Abbr. for “alternating current.”AC 1.On drawings, abbr. for “alternating current.”2.On drawings, abbr. for armored cable. 3.Abbr.for air conditioning. 4.Abbr. for “asbestos cement.”acacia Same as gum arabic.Acadian cottage Same as Cajun cottage.acanthus A common plant of the Mediter-ranean, whose leaves, stylized, form the charac-teristic decoration of capitals of Corinthian andComposite orders. In scroll form it appears onfriezes, panels, etc.absorption rate4absorption-type liquid chiller Equipmentutilizing a generator, condenser, absorber, evapo-rator, pumps, controls, and accessories to coolwater, or other secondary liquid, using absorp-tion techniques.ABS plastic A plastic of acrylonitrile-butadiene-styrene; has good resistance to impact, heat, andchemicals; esp. used for piping.abstract of title An outline history of the own-ership of a parcel of land, from the originalgrant, with changes in title, and with a state-ment of all mortgages, liens, encumbrances, etc.,affecting the property.abut To adjoin at an end; to be contiguous.abutment A masonry mass (or the like) whichreceives the thrust of an arch, vault, or strut.absorption trenchacanthusabutment AACB 1. Abbr. for asbestos-cement board. 2.Abbr. for “air circuit breaker.”accelerated aging The speeding-up of theaging process in a material; obtaining, in ashort time, the results that would occur in agingunder normal conditions. The most commonfactors that increase aging include exposure ofthe material to water, ozone, oxygen, or sun-light.accelerated life test A test in which one ormore parameters (e.g., temperature) is increasedor decreased beyond its normal or rated value todetermine the resulting deterioration within areasonable time period.accelerated weathering A laboratory testingtechnique to determine, in a relatively shorttime, the weather resistance of a paint film orother exposed surface.
accelerating admixture An admixture thatspeeds the setting and/or the early strengthdevelopment of hydraulic concrete.acceleration 1. The rate of change of thevelocity of a moving body. 2. The rate of change,esp. the quickening of the natural progress of aprocess, such as hardening, setting, or strengthdevelopment of concrete.acceleration of gravity (g) The accelerationproduced by the force of gravity at the surface ofthe earth. (By international agreement the valueof g is 386.089 inches per second square =32.1740 feet per second square = 9.80665 metersper second square.)acceleration stress In a wire rope (or thelike), the additional stress imposed as a result ofthe acceleration of the load.accelerator 1.A substance which, when addedto concrete, mortar, or grout, increases the rate ofhydration of a hydraulic cement, shortens thetime of set, or increases the rate of hardening orstrength development. 2.A substance, added witha curing agent, to speed a vulcanization processand enhance the physical properties of a vulcan-ized materia