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