.:Cl.~ent Mill Edition of

A Combination of CEMENT AGE of NeW" York, CONCRETEof Detroit, and CONCRETE ENGINEERING of Cleveland

meansaved.

SALES OFFICES: New York, Chicago, Philadelphia. Pilliburgb.Bo 100, Buffalo, Bollimore, Sovanoah

ALPHA PORTLAND CEMENT CO.General Offices: EASTON, PA.

Ilny nml nhthL ALPHA eheml rf14 nml('!wrnlf'ol engineers nr(' renl bo8se~,

In ('omJ)O·*Ion, lhorfluSd\ bumln".1111(' ~rin(lIllg 1I00l correct ngtngA LPH A Port Innll ('(>ment repr~enl8

the hlgh-wnler Ulark or (Iunllty. F.\'trybl\K flf .\l..PH.\ 1~ warrnnted to DlI retllan ll1~l stfinc.!:ml Sl>ectncntloJls.

8Jx grent plnuts 011 six trunk-Hnernllronds-one plAnt wItli prhnte ('I~('kA

dlrE'ClIy on the nt1()~f)n. Dnlly capocltyof t~.OOO barrels; storage for 2.000,000l.orrelf\.

Bringing Down 100, 000 Tons ofALPHA Cement Rock

Tlll~ vlrlure WI\S; lllk(>11 at the :\Jal'·Llll'~ ('I'~k (Pll.) ~\1.I'H.\ plaut nt. the11I1Il"' or ttdl1R liPAt ton of d.rnamiteluadt'(1 III tlllrl{'ell 6-inch hnleg horedJ70 (C'('t Jt'ep. down tho entire (nc,," orIlll"' (Itl:llr)", 11111.000 101111 (If the nnest('C'lIlt'llt rock \\t'rt' dt~IOllged.

Tlli~ ro('k hn ... just the pl'oporllonsfor II lX'rfe<.·' I"lrtlnud Cement.

JI1 ('\"(:'0' .\l.l'IIA plant ther(' is tho~;lllll' rigid t~!'Ilill" or eH'O' hurInG' nlldlilt:' "Olll(> cllreftll 1lI1\iuk I f the rock.Jllooll)Ct1illllS of the prodll('l ilre houri}",

The attention ofevery reader is di­rected to The Ed­itors' Page- page4 ofthe advertisingsection (the secondpage inside thiscover.)

Look there firstthis month, andevery month.

Three minutesdevoted to thispage willmore time

Office of Puhlica/ion, De/roil, Jlich.

Ready-Retercnec Index(Alphabetieal byTopies) of Editorial)lattel' Page 4-

Alphabetieul Index ofA(l\"el'tisers Page] 7

Classified Index of Ad-,"ertisements Page 17

Editorial Contents Page :n

Vol. IV No. 1

JANUARY, 1914

Concrete-Cement AgePublishing Co.

*1.50 per yr. 15c. per eopy

A Concrete Arch Bridge at the San Diego Exposition­Beautiful and Permanent·

FlO. l-ARCHlTEcr's PERSPECTIVE OF THE COMPLETED BarnoE

•

A combination of beautiful butsimple architecture, and a wonder­fully instructive revelation of thingsthat man is doing and how he isdoing them, how he lives, and how heearns his livelihood, with strikingcomparisons of the difference be­tween human aspirations and proc­esses used in this and in bygonegenerations, will make the San Diegoexposition in 1915 different, and thevisitor will find much of interest,pleasure, instruction and inspiration.The California State building, theEthnology building, the Puente Es­panol, the great bridge over CabrilloCanon forming the west entrance tothe grounds, are of reinforced con­crete. Of these structures the moststriking is the Puente Cabrillo. Itwill be a seven-arch bridge with en­closed beam and girder approaches.At either end there is an earth-filledretaining wall. These walls are ofthe "box" type, the sides being rein­forced slabs 12" thick tied togetherwith steel rods bedded in concrete.The end wall of this section is of thebuttress type. The two buttressesserve not only to take the overturn­ing thrust of the earth fill, but alsoto carry the ends of the concretegirders of the approach spans.

ftRUCTURAL FEATURES OF THE BRIDGE

The east approach consists of tworoadway girders, 240' c.-c., each 2'wide x 40' deep, and 14040' long, sup­ported by columns 240' c.-c., and twosmaller girders at the edge of the

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sidewalk, with transverse floor beams8' c.-c., carrying the floor slabs. Theparapet wall along this section iscarried to the ground, cQmpletely en­closing the girders and the support­ing columns. The west approach isa similar section 72' long.

The bold and unusual features ofthis bridge are in the section betweenthe two approaches. To the casualobserver, the structure will haveseven archcs each of 56-ft. span withpiers 12' wide. A closer inspection,however, will reveal expansion jointsat the crown of each arch. Thi'ldesign limits the effect of tempera­ture changes to the portions betweenthe crowns of adjacent arches. Todo this the bridge was designed notas a series of elastic arches, but as aseries of balanced cantilevers rest­ing on the piers.

Tile roadway slab is carried ontransverse floor bcams and the side­walk slab on 6-in. diaphragms whichalso tie the roadway and the side­walk cantilevers together.

The roadway cantilevers rest onreinforced columns. The sidewalkcantilevers are carried to the foun­dations as a reinforced section 15"wide and 12' long.

To stiffen the structure and morecompletely to tic the roadway and thesidewalk cantilevers together, a 6-ill.soffit is indicated between the road­way and the sidewalk cantilevers.The pier is 40 I' 8" wide but at thissection is divided into two parts,

COYCRETE-CEMENT AGE

which are connected by a transversearch. The piers below this sectionare stiffened by horizontal dia­phragms 8" thick and 15' C.-e.

The reinforcing of the 6-in. and8-in. diaphragms consists of a doublesystem of diagonals, usually of 1f2-in.

FIG. 2-PaELUlINARY WORK AT THE EASTApPROACH OF THE SAN DIEOO BIIlDOB

In the foreground is shown the workin some of the central piers. At this timeconcrete was being chuted from the mixerat the east approach, shown in the back­ground. This p~ant is shown in the cen­ter of Fig. 6. The bins for holding sandand stone for the main mixing plant areshown at the right. Note the diagonalreinforcing in the face of the pier wall

rods spaced 24" c.-c. The floorslabs are reinforced with Kahnshear bars, floor beams and gird­ers are reinforced with %,-in. barsand I-in. bars. All steel {or thebridge is being furnished by the

Ja_ary, 1914

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CONCRETE-CEMENT AGE

Flo. 4--GElfEIlAL VIEW OF "PUENTE CABRILLA" UNDER CoNlITIIUCTlON AT' THE SAN DIEGO EXPOSITION. AT THE EX'I'IlElIIE LEn.SnowN THE GRAVITY TOWER

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by a gate at the base operated by alever that raises the gate to each biDand admits the proper amount ofsand, rock and cement to a commonhopper which in turn dumps the ma­terial into a SO-cu. ft. mixer, thewater being supplied from a pipelet into the mixer itself. The mixerdumps with a lever into a hoist or"skip" operated in the 200-ft. scaf­fold built to carry the hoist with itslead, at the rate of 100' per sec.The skip dumps automatically intoa hopper at the required elevation inthe scaffold and the mixture fallsinto a sheet iron chute suspended ona 1f2-in.cable, the chute leading tothat portion of the structure at whichit is desired to dump the mixture.

Two men handle the materials andthe mixer at the bottom of the scaf­fold. One man operates the hoist-

Trussed Concrete Steel Co., Detroit.There will be used in the construc­tion of this bridge 7,700 cu. yds. ofconcrete and 450 tons of steel.

CONSTRUCTION METHODS

The necessity for economy in costsnecessitated the introduction of auto­matic methods as far as possible. Inhandling the materials for the mix­ture and the concrete after mixing,a system of chutes was devised, sup­plemented by a hoist at a centralpoint from which to pour the entirestructure.

Auto trucks bring the 'sand, rockand cement to a dump bin on the endof the east abutment. Two chutescarry the sand and broken rock toseparate bins in one structure at thebase of the center pier. The cementis also stored here. The bins open

FlO. 8--THIIl SHOWIl VERY MUCH THESAHE VIEW AS FlO. 51, 'VITH THE WORXFURTHEJl ADVANCED

In this view the central tower for hand-ling concrete has been built and is in FlO. 5--DETAIL VIEW OF THE EAST ApPROACHoperation. Work has been begun on theintermediate piers This shows In detail the walled-In approach span

JafMMJry,1914

CONCRETE-CEMENT AGE

FIG. 6---RUNNING THE BRIDGE FLOOR OS THE SAN DIEGO \VORK

This· is a detail ~;ew of the east approach. Of special interest is the use of sectional platform runways for the concrete buggies

ing machinery. Onc man attends thehopper at the top of the lift. Tamp­ers attend the outflow.

With this device a batch is placedevery 2 min. The segments of theCAntilevers require SO hrs. of con­tinuous pouring. All of the work ofdesigning and constructing the expo­sition's many structures is being doneby the Division of Works,-FrankP. Allen, Jr., Dir. All constructionwork is being carried on by forceaccounts.

An Interesting Water Tower

N ear York, England

The accompanying illustrationshows an unusual type of water re­servoir constructed bv the YorkshireHennebique Contractin~ Co., Ltd.,Leeds, Eng., near York, from thedesigns of L. G. Mouchel & Part­ners.

The object of the structure is toprovide for the storage of some25,000 gals. of water to be used asdomestic supplies and for farm andstable purposes·. The main portionof the tower was formerly part of awindmill, but is now lined with rein­forced concrete so as to form a per­fectly water-tight chamber. Theupper portion is a cylindrical cham­ber built elltirely of reinforced con­crete, the upper and the lower reser­voir being separated by a floor of'the same material.

Water is delivered by pumps intothe upper or high pressure reservoir,the capacity of which is 9,000 gals.,and the lower reservoir, capable ofcontaining 16,000 ~als., is served b~!

an overflow pipe fitJed in the centerof the chamber above. Each com­partment is provided with a 4-in.delivery pipe and valve so that sup-

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OTHER CONCRETE STRUCTURES

Many other permanent structuresplanned by the exposition will bebuilt of concrete. The Californiabuilding at the east end of the bridge,with its tower rising 180' above thelevel of the bridge floor, will be builtof reinforced concrete.

Concrete is being used in the con­struction of the sanitary and thestorm water sewer systems as beingthe most economical material for thispurpose.

plies can be drawn off as required.The top of the upper reservoir iscovered by a reinforced concrete flatroof, to which access is gained bymeans of the spiral stairway shownin the iIlustration.

Standing on high ground and ris­ing to the height of 30', the tower ofthe old windmill appeared to offerIUl excellent and ready-made supportfor water storage tanks. The origi­nal intention probably was simply toinstall cast iron tanks on the top ofthe tower after removal of the millfittings, and that the proprietor af­terwards decided upon the adoptionof reinforced concrete as a moreeconomical material, of greater dur­ability than metal, and offering thefurther advantage that being quiteunaffected by corrosion it would re­quire no paintin~ or maintenancecharges or- any kind.

The design prepared by ~louchel

& Partners exhibits features of de­cided originality, for instead ofmerely utilizing the old masonrytower as a support it provided, asalready stated, for converting theinterior into a low-pressure reser­"oir, thereby effecting a very consid­erable reduction in the cost of theworks.

AN OT.n "'Il;n~II\.1. !\"EAR YORK, ENG.,CON~'ERTED I NTO .~ )-IO:>ERN REINFORCED

CONCRE'l'E WATER TOWER

A reinforced concrete floor atground level forms the basis for athin monolithic casing of reinforcedconcrete carried around the interiorwalls and covered by a circular floor,IIpon which is built the h'igh-pressurecvlindrical reservoir with walls 6'"thick, rising to the further height of18', and finished bv a castellatedparapet S' above the' flat roof.

January, 191-1

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