Published Monthly by the August, 1962PRESTRESSED CONCRETE INSTITUTE Vol. 8, No. 8

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I Prestress Corepony, Jacksonville, Florida

Dramatic prestressed slab cantilevers 24 ft. - 9 in. in eachPRESTRESSED CO~CRETE INSTITUTE direction forming a canopy for the striking entrance to

the Reynolds, SmIth and Hills’ office building in Jacksonville. The 49 ft. 6 in. long slab is supported only at thecenter by a post-tensioned, hung connection, It has aconstantly varying cross-section measuring 10 ft. at itswidest point, and ranging between 3 to 12 inches thick.

Some of the things that so often plaguethe minds of architects and engineersare the little things. The openings inmembers for utilities, fastenings for fixtures, inserts in beams, blockouts, ceil.ings, etc. These problems are not uniqueto prestressed concrete but perhaps someof the solutions given here to thesetroublesome small details may providesome useful ideas.

ANCHORS

Anchors are the basic device forattaching most things to concrete. Fundamentally, anchors can be broken downinto two catagories, the pre-set anchor(usually called an insert) placed in theconcrete before it hardens and the typeof anchor set after the concrete hardens.

A properly installed pre-set anchorwill doubtlessly do the job it was intended to do. Its holding power is usually accurately predetermined and it isusually tailor-made for the fixture itsupports thus simplifying fastening. inspite of these advantages the pre-setanchors have several disadvantages thatoften outweigh their merits. Their mostobvious disadvantage is the cost anddifficulty of accurately placing them.Typical prestressed members are invariably cast in steel forms. About the onlyeffective way to insure an insert willbe accurately placed is to drill a hole inthe steel form and firmly attach the insert to it with a sheet metal screw orbolt. After a complicated job with manyinserts a set of forms can resemble apiece of swiss cheese. These form holesafter the completion of the job must bewelded closed and then ground smooth.

Another important consideration aboutpre-set anchors is that their locationmust be carefully and accurately studiedbefore hand, because once installed thepre-set anchor cannot be moved or ad-

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justed. Since prestressed members maybe cast months in advance, later attachment revisions may render the pre-setanchors worthless. And since they mustbe carefully placed in the forms andrepair of steel forms may be necessary,they are costly.

Other fastening alternatives are casting holes completely through the members or supporting fixtures by ties hungthrough the joints between precast members. Excessive or large holes in thestems are to be avoided while “poke”holes in the double-tee flanges are relatively easy to establish. Various typesof wire hangers with “pigtails” can bedropped thru the holes as a suspensionsystem.

As an alternate to inserts, the anchorscan be installed after the concrete hardens. A common way to do this is tofirst drill a hole in the hardened concrete,then to insert the desired anchors. Manyanchoring devices use the expansionprinciple. This type of device has anexpansion sleeve which wedges into thepre-drilled hole as the bolt or fasteningdevice is screwed in the threaded anchor.

One way to insure the accurate placement of all inserts is to set up a grid-module. The Architect-Engineer oftentries to show the general configurationof the beam and locate attachments inthe drawings. However, this cannot beaccomplished readily without planning.Frequently it waits until the beams areactually placed in the field and all tradessecure their members to the precast sections. However by setting up ii grid forthe job, inserts can be set for themechanical, electrical, and plumbingtrades simultaneously.

In calculating the capacities of anchoring systems several things should beconsidered. The ultimate load of thedevice should not be used in the field

as the ultimate load is based on a straightpull which is seldom the case in thefield. Also besides dead load, impactstresses can exist ranging up to 50%of the dead load.

EXPLOSIVE DRIVE FASFE ERSWhile the pre-drilled anchors have

been used for a long time and will continue to be popular in future years, another way of fastening articles to hardened concrete is growing in use. This is thesystem of shooting pins and studs directly into the concrete by means of anexplosive powder actuated device. Thetool is a pistol-like instrument that iseasily loaded and handled. The pins andstuds penetrate the concrete at velocitiesof from 800 to 1,800 feet per second.This high velocity literally fuses the concrete to the drive pin. The shank diameter of the fastener and the compressivestrength of the concrete determine theultimate holding power.

Spalling may occur on the concretesuface at the fastener if the shear strengthof the concrete is exceeded because ofthe tremendous compression force. Ex-~cept for appearance the spalled areasare not a serious matter since they donot importantly decrease the holdingpower of the anchor. This spalling canbe reduced by using a spall-reducer orby driving the fastener through a steelfinishing device.

EPOXIESEpoxy resin compounds have also

been used to secure various fasteningsin place. They have been both used tofasten inserts to forms before the concrete is poured and also to attach appurtenances to precast members. Theimportant considerations are that thesurfaces to be joined must be clean andsound. A bonded connection is neverbetter than the quality of the contactingsurfaces.

Prestressed members themselves canbe used as utility runs. Adjacent legsof double tees can be closed in at thebottom producing lighting fixtures, orhot air ducts. Hollow core slabs provide excellent ready made raceways forutilities and mechanical equipment. (seepage 5 for examples.)

So don’t let the little things growinto big things. Some careful thinkingin advance will enable you to makethe simplest and least expensive connection to a prestressed member andperhaps suggest a means to take advantage of their convenient shapes.

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Details of several typical means of supporting utilities from prestressed members. These same types of connections are applicable to any prestressedstemmed member.

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Courtesy of Architectural Record Magazine and Architect Minoru Yomasaki

CBS Electronics Building, Lowell, Mass. Attractive ligitures were attached between the webs of the double ic~he webs act as reflectors. The double tee’s are leftand painted and acoustical tile was placed on the sicthe continuous flourescent fixtures.

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Francon Ltd., Montreal, Quebec

Assembly room, St. Dorothee, P. Q. Town Hall in . -

Canada. Ball lighting fixtures are suspended between the exposed double tee’s creating a strik- . /ing contrast to the dark cord glued between thewebs. -

R H. Wright, Inc., Fort Lauderdale, Florida

Multiple-outlet electrical duct work Iacast prestressed hollow core slab fIFt. Lauderdale Office Building. Ductsered by the floor topping. Hangersother utilities from the ceiling cannoted.

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Office building employing ceiling lighting b~enclosing the bottom of adjacent double teestems.

Structural Concrete Corporation, Laconia, New Hampshire

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Courtesy of Architectural Record Magazine and Architect Minoru Yamasaki

CBS Electronics plant cafeteria where the exposed prestressed doubletee’s were complimented with attractive fixtures and by filling alternate spaces with acoustical tile.

Blakeslee Prestress, New Haven, Connecticut

Swimming pool in Naugauck, Conn. High Schoolshowing simple handling of a cut-out in a prestressed roof. The single tee’s are sprayed withacoustical plaster.

Prestressed Concrete, Inc., St. Paul, Minnesota

Beauty Shop employs prestressed channel slabswith lighting fixtures attached between webs.

Blakeslee Prestress, New Haven, Connecticut

Heating ducts supported by hangers from the jointsbetween the prestressed double tee’s.

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Concrete Research, Inc., Waukesha, Wisconsin

Waukesha shopping center showing fixture and ceilingtreatment indicating uncluttered ceilings possible withprestressed construction.

Utah Prestressed Concrete Company, Salt Lake City, Utah

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Double Coil Rod Anchor with taperedsetting studs. Six of these units areembedded in each end diaphragm ofthe 65 ft. long 250 ton deck sectionfor erection of the new Slidell bridgeover Lake Ponchartrain.

Concrete Structures, Inc., Richmond, Virginia

LIGHTING WITH PRESTRESSEDMEMBERS

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Blakeslee Prestress, New Haven, Connecticut

Below are illustrated a few of the manytypes of lighting arrangements possible withtypical prestressed stemmed units. Thesketches give examples of open cove lighting, surface-mounted directional lights, dif..fused lighting, hung fixtures, and a luminous ceiling arrangement.

Altman’s Parking Garage, White Plains, NewYork. Electrical conduit was passed throughholes cast in the prestressed single tee’s,and the fixtures were hung from it or frompower set fastenings.

Superior Concrete Accessories, Inc.

Walker manufacturing building, Harrisonburg, Virginia. Thespace between the double tee legs is used as an air duct witha sheet metal seal on the bottom. Lights were recessed between the webs also and reflecting paint was used. Ten inchholes were cast in the “1” beams for the passage of pipes.

ELECTRICAL DETAIL WITH CORED SLABS.

OUTSTANDING PROGRAM PLANNED FOR 8th ANNUALPCI CONVENTION IN NEW ORLEANS

The 8th Annual Convention of thePrestressed Concrete Institute at theRoosevelt Hotel in New Orleans, September 23-28, promises to be one of themost outstanding meetings on prestressedconcrete ever held in the United States.The members of the Arrangements Committee and the Technical Activities Committee have worked very hard to makethis a reality.

The highlights of the Convention’sprogram will be:

Felix Candela, as the Keynoter, is bestknown for his daring shell structures.The world noted authority on partialprestressing, Dr. P. W. Abeles will present a paper. Professor T. Y. Lin willspeak on the load balancing concept ofprestress design. A paper will be presented on the Medway Bridge which hasa 500 ft. main span and two 313 ft. flanking spans. The highly publicized FederalScience Pavalion at the Seattle World’sFair will be the topic of another interesting paper. The design of dual purpose blast and fallout shelters will alsobe outlined, and an entire half day session will be devoted to connection detailsin precast construction. A full sessionwill be devoted to PCI Technical Committee reports. With their many accom~plishments this past year this should bemost interesting. Technical papers onlimit design, computer design and theAASHO Test Road will also be given.Reports of research at the PortlandCement Association and the Associationof American Railroads are planned. Theprogram is given on the right and shouldinclude subjects of interest to everyone.

Sidewalk Scene French QuarterNew Orleans

1962 NEW ORLEA S CONVENTIONRoosevelt Hotel

PRELIMINARY PROGRA

Saturday, September 229:00 AM. to 5:00 P.M.

Board of Directors Meeting

Sunday, September 23:12:00 Noon to 6:00 P.M.

Registration12:00 Noon to 5:00 P.M.

Technical Committee Meetings

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Monday September 24:8:00 AM. to 12:00 Noon

Registration9:00 AM. to 10:30 AM.

PCI Members’ BreakfastPCI Business Meeting

11:00 AM.Opening Session

Chairman—D. W. MilhanPrestressed Concrete Products Co., Inc.Mandeville, Louisiana

WelcomeRobert J. Lyman

President PCI

F.I.P. Congress ReportBen C. Gerwick, Jr.

Designing Dual Purpose SheltersNeal FitzsimonsDirector, Protective Structures Div.Office of Civil DefensePentagon, Washington, D.C.

Fabricating Material for FederalScience Pavilion

George DuecyAssociated Sand & GravelEverett, Washington

Long Span Bridge Design0. A. KerenskyFreeman, Fox & PartnersLondon, England

6:30 P.M.—Get Acquainted PartyExhibit Area

Tuesday Morning, September 25:7:30 A.M.—PCI Active and Associate

Members’ BreakfastDiscussion of next year’s activities

9:00 A.M.—General Session—DesignLoad Balancing Concept

T. Y. LinProf. of Civil EngineeringUniversity of California

Computer DesignAndrew St. JohnMidwest Research InstituteKansas City, Mo.

Limit Design with Prestressed ConcreteW. Burr Bennett, Asst. ManagerStructural & Raliways BureauPortland Cement Association

Partial PrestressingP. W. AbelesConsulting EngineerLondon, England

Concurrent Session

9:00 A.M.—PCI Marketing Committee ReportsAdvertising ProgramAwards ProgramContract Forms

10:30 A.M.—Where is the PrestressingIndustry Headed?

Discussion moderated byWilliam Avery, PublisherConcrete Construction MagazineChicago, Illinois

LUNCHEON

Gantry Cranes at Prestress Plantto be Toured, Mandeville, Louisiana

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Federal Science PavilionSeattle World’s Fair

Keynote AddressFelix Candela

Architect-EngineerMexico City, Mexico

Monday Afternoon, September 24:2:00 P.M.—General Session

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Superior Concrete Accessories, nc.

Tuesday Afternoon, September 25:1:30 P.M. eneral Session

Precast Concrete ConnectionsChairman: Thomas A. HansonHanson & CraigRichmond, Va. ~j~~t~2’c,

Column Base~and~Irwin J. SpeyerNew York, New York

Beam to Column ConnectionsAlfred A. YeeAlfred A. Yee & AssociatesHonolulu Hawaii

Beam to Girder ConnectionsLaurence CazalyConsulting EngineerToronto,, Canada

Wednesday Morning September 26:9:00 AM. eneral Session

PCI Technical Committee ReportsChairman: Ross H. BryanConsulting EngineerNashville, Tennessee

Fire ResistanceA. H. GustaferroPortland Cement Assn.Chicago, Illinois

GroutingMyers Van BurenRaymond InternationalNew York, New York

WorkmanshipPrecast Industries, Inc.Kalamazoo, Mich.

Building CodeT. Y. LinEngineering Dept.University of Calif.Berkeley, Calif.

AREA LiaisonHarold R. HutchensThe Carter-Waters Corp.Kansas City, Missouri

AASHO-PCI InspectionWilliam E. DeanFlorida State Road Dept.Tallahassee, Fla.

PavementsEdward SchechterStressteel Corp.Wilkes-Barre, Penna.

ResearchMete SozenUniversity of IllinoisUrbana, Illinois

CuringJohn L. BeatonState of Calif. Div. of HighwaysSacramento, Calif.

Post TensioningAdolph WalserJos. T. Ryerson & Son, Inc.Chicago, Illinois

Shrinkage and CreepArthur R. AndersonConcrete Technology Corp.Tacoma, Wash.

Prestressed Concrete Bridges in theAASHO Road Test

G. S. VincentSec. AASHO Bridge Comm.U. S. Bureau of Public Roads

Association of American Railroads Researchon Prestressed Concrete

F. P. Drew(paper co-authored by E. J. Ruble)

Research EngineerStructuresAssociation of American RailroadsChicago, Illinois

SouthwestW. C. GivensCapitol PrestressJacksonville, Florida

Central StatesJack R. WayNebraska Prestressed Concrete Co.Lincoln, Nebraska

NortheastTo be announced

WestL F. StansburyJohn A. Roebling’s Sons Corp.San Francisco, Calif.

11:00 A.M. to6:00 P.M—Field Trip to Mandeville, La. to

Prestressed Concrete Products Plant

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lIe’- - ~fl1S~~-T’~Y~hin’-&~Associates~ Medway Bridge, England

Floo andsR~f~SIäb~t~MasonryExhibit AreaH. Carl Walker •WaI4s— 12:00 Noon Buffet Luncheon

Precast Industries, IncKalamazoo, Mich. ~ ~~ednesday Afternoon, September 26:

2:00 P.M. eneral Session5:00 P.M.—Connections Workshop ~ Research and DevelopmentDiscussion Session

6:30 P.M—Annual Banquet Report on Studies Relating to PrestressedConcrete at the PCA Laboratories

Joseph Walker, V. P.Portland Cement AssociationSkokie, Illinois

CONSTRUCTION USINGPRESTRESSED CONCRETE

TRUSSAn unusual application of prestressed

concrete is the use of a two-span continuous truss as the front supportingmember of a small store. The trusssupports 43 ft. long double tee roofslabs which cantilever 10 ft. over thestore’s entrance.

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Prestressed Concrete Truss In Place

The truss has a total length of 52 ft.and an overall depth of 3 ft. 4 in. It issupported by 8 in. x 8 in. exterior and8 in. x 21 in. interior cast-in-place columns. The truss has a 5 ft. overhangat each end. The vertical members ofthe truss, spaced at 5 ft. on centers, havean 8 in. x 8 in. cross-section except forthe center one which is 8 in. x 12 in.

The truss was pretensioned and formed as a single unit in a horizontal position. It was removed from the castingbed using two lift points (the designincluded this loading condition) andhauled to the job site. After the trusswas in place and welded to the columns, it was shored under each interiorvertical member during the erection ofthe double tee roof slabs and the placement of the topping. The purpose ofthe shoring was to eliminate stressescaused by unsymmetrical loading of thetruss spans. This gave the contractorfreedom to place the roof slabs at random over the entire roof. Three dayslater the shoring was removed.

The truss was designed by A. M.Ozell, Consulting Engineer, and cast byWest Coast Shell Corporation for LittleStar Stores.

Thursday Morning, September 27:9:00 A.M. eneral Session

Production TechniquesRegional Reports on New

Production Ideas

AASHO Test Read

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REPORT ON THE RECENT F.I.P.FOURTH WORLD CONGRESS

Over 1300 engineers and architectsincluding 70 from the U.S.A. attendedthe Fourth Congress of the FederationInternationale de la Precontrainte heldlast May and June. The first sessionswere held in Rome and included fieldtrips to some of Nervi’s outstandingstructures. Then the Congress movedto Naples for the final sessions, andfinally, a study tour inspected outstanding buildings and bridges in Florence,Bologna, Milan and Turin. Italy wasa fortuitous site since it was able toprovide above all, a sense of architectural continuity from the ancient aqueducts and buildings of Rome to themagnificent prestressed structures oftoday. National reports and individualpapers and discussions covered manythemes; durability and fatigue, siteproblems and difficulties, economics,precast factory-manufacture. outstandinabridges and buildings, and prestressedroads and airfields.

The very size of the Consress and itsoverflow attendance with wide diversityof subjects, and five official languages,was occasionally perplexing. But considering the numerous new ideas andfacts presented the Congress proved tobe a highly informative and stimulatingmeeting.

Individual highlights of the programincluded segmental construction utilizingurecast concrete elements, plant manufactured and assembled on the site bypost.tensioning to form long span bridgesand space structures; precast thin shellsand folded plates; and numerous beautiful bridges of prestressed concrete withspans of 400 to 700 ft.

Mr. Ben C. Gerwick, Jr., formerPresident of PCI, will present a corn-

plete report on the recent FIP WorldCongress at the forthcoming PCI Convention. Mr. Gerwick, who was theGeneral Reporter for Theme IV “Precast Factory Manufacture and Standardization” did an excellent job of representing PCI and the United States at theRome Congress. It is planned to publishseveral papers included in his presentation in future issues of the PCI Journal.

1962 CONVENTION IN NEW ORLEANSTO FEATURE EXCELLENT MATERIALS

AND EQUIPMENT SHOWThe Co-Chairmen of Exhibits for the

1962 New Orleans Convention, Mr. H.0. Whitehurst and Mr. E. E. Schultz,both of Plant City Steel Corporation,have announced that many booths havealready been reserved for the September23.28 Prestressed Concrete Materialsand Equipment Show. This show, heldin conj unction with the annual PCI Con.vention, has proven to be an attractionto all convention goers. Because of theenthusiasm with which it was met lastyear, the “Buyers’ Guide” will againbe published for the 1962 ConventionThe “Buyers’ Guide” containing productliterature, will have complete information on all items displayed at the show.

PROFESSIONALARNOLD H. BOCK

4959 Sunshine DriveSt. Louis, Missouri

HON KWAN CHENGArchitectural Office, P.W.D.Hong Kong

ARCESIO CONSTAIN M.Apartado Aereo 12-285 BogotaBogota, Columbia

ALEV KOKTURK33 Fountain StreetWest Newton 65, Mass.

MAX de VERTEUIL498 Delmar, Apt. 4Pointe Claire, P.Q.Canada

AFFILIATECHARLES H. MARTIN

Box 1254 OCSLa Fayette, Louisiana

ALFREDO A. SALAZARP. 0. Box 1286Atlanta 1, Georgia

JUNIORWILLIAM G. HARTLINE

3124 Spaulding StreetOmaha, Nebraska

B. RICHAL SMITH8232 Second Ave., North EastSeattle 15, Washington

I 8THI .._4nnua/Convent,’on

PRESTRESSED CONCRETE INSTITUTE

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PRESTRESSED CO TE INSTITUTE

205 W WACKER DRIVECHICAGO 6. ILLINOIS

MEMBERSHIP APPLICATIONSAPPROVED BY

BOARD OF DIRECTORSACTIVE

S. T. GRISWOLD & CO., INC.P.O. Box 406Essex Junction, Vermont

MORSE BROS. INC.P.O. Box 117Harrisburg, OregonMr. W. F. Morse

WINKRETE PRECAST CO.300 Long Branch Rd., Box 1366Syracuse, New York

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ROOSEVELT HOTEL Sept. ~ Z3-2 SNEW ORLEANS, LOUISIANA ~

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