( ... LEuct Spacing Not Ct11lcol Total Number of Bars 1s VERY ffl PC)rtant Fig. 11-4 Bars ln Slabs and Wallo As loog as the totll number of rcinfurcing btil S specified is maintained, a rea­ SON1ble tolerance in spacing individual bars is,t J inches, except where open­ ings, inscr18, or cmbcdcled items, might require some additional shifting of bars. Where reinfun::ing bars ue spaced in ~labs or walls in Yi inch increments im1Cad of whole inches, the """"' result is obcained by alternating the next smaller and the next larger inch. For example, 121/2-inch spacing equivalent is obrained by alternating the bar spacings 12 inches, 13 inches, 12 inches. 13 inches, and so oo. Lateral Spacing of liars in Joist', Bttm J and Girders. Thc ACI Building C~ Sp«ifies the minimum amount of OOll<retecovcrovcr slimrj,s, ties and od>e< rein­ fon:inj: bars, as well as thc minimwn clear ~ bel....,.., bars. The American Ass«iation of $rate Higl!way and TJ1111>,x,rtation Officials (AASHTO) estab­ lishes the minimum amouot of coo=ecove r "'"' reinfotcing bars in bridges. In either case. the Engineer should ddetmi11e whether or not che minimum concrete Ct M< or spacing would req,,i,,o a second or third layer of reinfon:ing ban. A certain amount of wiring of reinfon;iog bais lo bar supp Ol1S and lo stirrups and ties will be required to keep the longitudinal bars r=onablystraigh t, parallel, and at the proper latcrnl spocir1g. lley()tld that, additional tying is UMCcessary; When beams or girders wi1h many reinforcing h3JS are S1l Jll>ORed by columns that are heavily r<inforce<I, it is some<imes helpful to make a fulhi. zcd template for such intcrscctions to hold the oohmm vertical bars in such a position that the beam bars will later pass around the column bas satisfactorily. When these bars cross at dgbr angles, it is acccpiablc for them to be in contact wi01 each other. l. ocatlnn of First and La5t Bar. If neither the p acin~wm~ nor the Engi.. """"'s typical det2ils show where lbe first and last reinfordn_g bars;. a run are to J,,c pla~ i1. (s n:. @. mmcrull&Uiat the spa~ shown m Figs. l-5 through ITTfbe loll 11-6 concrece Aeinf~ Stoel lnctiluto Section 609 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 6-9