Open$20Web$20Longspan$20and$20Deep$20Longspan$20Steel$20Joists$20 $201968

EXTENDED TOP CHORDS AND OUTRIGGERSH-SERIES

Outriggers and Extended Top ChordsOutriggers are extensions to the top chords of joistsfor the support of overhanging roofs. They consist ofseparate members attached to the joists in the shop.

In case of short overhangs and moderate loads, thetop chord may be extended.

EXTENDED TOP CHORD

TWO-CHANNEL OUTRIGGERONE-CHANNEL OUTRIGGER

INSPECTION AND TESTING OFBETHSPAN COLD-FORMED JOISTS

To insure that all Bethspan joists (cold formed chords)are of the same high quality, a comprehensive inspec-tion and test program is used. This program, which isas thorough as commercial production will allow, isimplemented through the following procedures :1.

2.

3.

4.

Samples of chord sections are tested to determinethe presence of required physical properties.

Conformance to dimensional standards, propercentering of webs on chords, weld appearance, etc.,are assured by a visual inspection on each joist as itis being assembled.

A manual test on nearly 30 per cent of all weldsprovides a quick preliminary check on weld qualityduring the assembly operation.

Finally, and very important, four per cent of ourjoist production (one joist out of every 25) ismachine-tested to insure that all welds meet thespecifications for joint strength as approved bythe Steel Joist Institute and the American Instituteof Steel Construction.

It is our machine testing procedure which enablesBethlehem to claim the manufacture of one of thefinest joists in the industry. Our quality control servestwo important functions. First, it insures that the qual-ity expected of automatic welders is being constantlymaintained. And second, because of the testing fre-quency, substandard welding becomes evident in timeto make adjustments on the welders, and repair de-fective joists before shipments are released.

Test ProcedureUpon selecting and placing a joist for machine testing,a predetermined horizontal shearing force is applied ateach interior* panel point where a resistance weld joinsthe chord and web members. Two welds are testedsimultaneously. The amount of force applied varieswith the section being tested. However, the forceequals at least two times the theoretical shear strengthof the most critical weld in the particular joist beingtested. If any weld is unable to resist this force, it isconsidered substandard and the joist is set aside for

BETHLEHEM LONGSPAN ANDDEEP LONGSPAN STEEL JOISTS

LJ- AND LH-SERIES

Bethlehem’s LJ- and LH-Series joists are now beingmade using tee sections for both top and bottomchord members. The results are a clean, unclutteredappearance and lower maintenance costs since effec-tive field painting is simplified.These tee-chord longspan joists are lightweight Warren-type steel trusses. The web system consists of a combi-nation of single and double angles which are weldedto the chords. These joists meet SJI and AlSC designspecifications.Bethlehem LJ- and LH-Series joists are furnished withparallel or pitched chords and with top- or bottom-bearing ends. The standard depth of bearing for long-span joists (top bearing) is 5 in.

Parallel ChordsParallel-chord LJ- and LH-Series joists can be fur-nished with any combination of top- or bottom-bearing ends.

Pitched ChordsBethlehem LJ- and LH-Series joists can be suppliedwith the top chord sloping in one direction or slopingin both directions from the midpoint to provide forroof drainage.Pitched-chord LJ- and LH-Series joists are availablein any combination of top- or bottom-bearing ends.They are made with the same number of panels as thecorresponding parallel-chord joists.The standard slope of the top chord is ‘/s in. per ft.The total rise or drop of top chord measured at mid-span for spans from 22 to 96 ft is given in the table.

Drops other than the standard aflect the carrying capac-ities and special design and fabrication are necessary.Carrying capacity is determined by the depth at themiddle of the clear span, which is the nominal depthof the joist.

RISE OR DROP OF TOP CHORD

ft62646668707274767880

ft8284868890929496

Itire orDropin.5%5%5%5%5%5%5%6

CAMBERAll LJ- and LH-Series joists are cambered in accord-ance with the following:

Top Chord Approx Top Chord ApproxLength Camber Length Camberft-in. in. ft-in. Ill.30-o % 70-O 2%40.0 % 80-O 2%50-O 1% 90-o 3%60-O 1% 96.0 4

BLJ- AND BLH-SERIESBethlehem’s BLJ- and BLH-Series Deep Longspanjoists are available in 52, 56, and 60 inch depths andlengths up to 120 feet. Tee sections are used for bothtop and bottom chord members. The web system con-sists of a combination of single and double angleswhich are welded to the chords.

Design and unit stresses of the Deep Longspans are inaccordance with SJI and AISC specifications for LJ-and LH-Series joists. However, the sizes of DeepLongspans are beyond the scope of SJl and AISC loadtables. Therefore, special load tables have been de-veloped. These begin on page 32.

The total safe load carrying capacities of BLJ and BLHjoists shown in the load tables are based on uniformlydistributed loads. Concentrated loads should be intro-duced at panel points to avoid local bending stresses.Where concentrated loads are involved, special analy-

sis should be made to ensure against overstressing.Assistance is available from Bethlehem in making thisanalysis.All BLJ- and BLH-Series joists can be fabricated withsquare ends or underslung. All joist depths are desig-nated by the depth at the center of the span.

CAMBERBLJ- and BLH-Series joists are cambered in accord-ance with the following:

Top Chord Length Approx Camber(fQ (in.)90 3%96 4100 4%110 5120 6

SPECIFICATIONS FOR BETHLEHEM JOISTSScope-The contractor shall furnish and install allmaterial to complete the open-web steel joist framingas shown on the drawings or as specified herein.Material shall include joists, bridging, anchors, andheaders. The following shall be considered as separateitems: centering, temperature reinforcing in concreteslabs over joists, loose or continuous bearing platesand anchor bolts for same, loose framing at over-hangs, and steel framing between joists not to exceedjoist spacing.

Joists shall be Bethlehem steel joists-J-, H-, LJ-,LH-, BLJ-, or BLH-Series.

The steel shall conform to one of the ASTM spcci-fications of latest adoption designated in the SJl andAISC specifications.

J- and H-Series joists shall receive a shop coat ofprotective paint before shipment. Cold-formed joistsshall be primed with a red oxide paint. Hot-rolledjoists shall be primed with black asphalt paint. LJ-,LH-, BLJ- and BLH-Series joists shall receive a shopcoat of zinc-chromate primer before shipment.

Design of J-, H-, LJ- and LH-Series steel joists shallconform to the latest SJI and AISC requi rements .BLJ- and BLH-Series joists shall conform to thelatest SJI and AISC requirements for LJ- and LH-Series joists. Joists are designed to support their fulldesign load when the top chord is stayed laterally bythe slab or roof deck. The weight of partitions whichextend across joists must be included in the designload. Where partitions occur parallel to joists, thereshall be at least one typical joist provided under eachsuch partition and more than one such joist shall beprovided if necessary to safely support the weight ofsuch partition and the adjacent floor less the live loadon a strip of floor one foot in width.

Span-The clear span of joists shall not exceed24 times their depth except that for floors the clearspan of H-Series joists shall not exceed 20 timestheir depth.

Spacing-Joists shall be spaced such that the loadingon each joist does not exceed the allowable loadgiven for the particular designation and span in theload tables. Joist spacing shall be compatible withslab design requirements.

Location-In wall-bearing construction, the cleardistance between end wall and first joist shall beapproximately 4 in. for J- and H-Series, and 6 in. for

LJ-, LH-, BLJ-, and BLH-Series joists. In steel frameconstruction, if beam and joist are at the same eleva-tion: the first joist shall be a full space from spandrelor wall beam. Joists shall be a full space from tiebeams, where the tic beams have the same elevationas the joists and a moment of inertia and resistingm o m e n t n o t less than that of the joists. Wherepartitions occur parallel to joists, an extra joist shallbe placed under such partitions, if necessary tosupport the additional load.

Bearing-Where joists rest on masonry or concretesupports, the length of bearing shall be not less than4 in. for J- and H-Series and 6 in. for LJ-, LH-, BLJ-,and BLH-Series joists.

Where joists rest on steel supports, the length ofbearing shall be not less than 255 in. for J- andH-Series, and 4 in. for LJ-, LH-, BLJ-, and BLH-Series joists. Where opposite joists butt over a narrowsteel support and positive attachment is provided bywelding or bolting, a shorter bearing length may beused, if permissible stresses are not exceeded.

Anchors-J- and H-Series joists. Ends of everythird floor joist and every roof joist which rest onmasonry walls shall be anchored thereto with ananchor equivalent to a s/s-in. steel bar at least 8 in.long. In roofs where there is no parapet to hold downthe joists, two r/z-in. round anchor bolts or otherequal means shall be used in lieu of the s/s-in. steelbar anchor. Ends of every joist resting on steel sup-ports shall be anchored thereto with one */i-in. bolt ortwo welds I in. long.

LJ-, LH-, BLJ-, and BLH-Series joists. Ends of everyjoist which rests on masonry walls shall be anchoredthereto with an anchor equivalent to a s-in. roundsteel bar not less than 12 in. long. In roofs wherethere is no parapet to hold down the joists, two+&-in. anchor bolts or other equal means shall beused in lieu of the s/4-in. steel bar anchor. Ends ofevery joist resting on steel supports shall be anchoredthereto with two bolts or welds.

Bridging shall be installed before construction loadsare placed upon the joists. Ends of all bridging linesterminating at walls or beams shall be anchoredthereto.

Bridging for J- and H-Series joists shall consist ofcontinuous horizontal members not less than r/t-in.round, one at top chord and one at bottom chord,

attached by welding. The I/r between connectionsshall not exceed 300. Bridging lines shall be locatedas follows:

Span I Number of Lines of Bridging

up to 14 ft One line near middle of spanOver 14 to 21 ft Two lines at +‘j points of spanOver 21 to 32 ft Three lines at 5/4 points of spanOver 32 to 40 ft Four lines at l/s points of spanOver 40 to 48 ft Five lines at I/ points of span

For LJ-, LH-, BLJ-, and BLH-Series joists, bridgingshall consist of bolted cross-bracing composed of notless than 1 x x 1% x ‘/ in. angles. The l/r betweenconnections shall not exceed 200. The maximumspacing of bridging lines shall be:

Chord Size Maximum Spacing of(final digits of Joist Lines of Bridging

Designation) (feet)02 to 08 incl. 1109 to 14 incl. 16I5 to 19 incl 2120 to 22 incl. 26

Centering for poured concrete floor and roof slabsshall be Bethlehem Slabform, which shall be fur-nished either unpainted or galvanized as required,and shall be attached to every joist at intervals notexceeding the cover width of sheets, in accordancewith the manufacturer’s instructions.

Camber-All LJ-, LH-, BLJ-, and BLH-Series joistsshall be cambered.

Inspection-All steel joists shall be inspected bythe manufacturer before shipment to assure thatmaterials and workmanship conform to the require-ments of these specifications. The manufacturer shallprovide access to his shop for outside inspectionif required.

Handling and Erection-Joists shall be unloadedcarefully from truck or car and stacked either by handor crane. Dumping on the ground shall not bepermitted.

Hoisting cables shall be attached to the top chord ofLJ-, LH-, BLJ-, and BLH-Series joists at panel pointsnearest the third points of the span, and shall not bereleased until the bridging line nearest midspan isinstalled for spans up to 60 feet, until two bridginglines ncarcst the third points arc installed for spansof over 60 feet up to 90 feet, or three bridging linesnearest the quarter points are installed for spans over90 feet; and the ends of bottom-bearing joists havebeen restrained laterally.

Excessive concentrated loads shall be avoided duringthe construction period. Such loads shall be so distrib-uted that the capacity of the joist is not exceeded.

PROTECTIVE PAINT ON BETHLEHEM JOISTSAll Bethlehem joists are coated with protective paintprior to shipping. Paints used for the various types ofjoists have been standardized and all paints conformto Steel Structure Painting Council Specification15-66T.

electrostatically sprayed with a red oxide shop coat.J- and H-Series hot-rolled joists are dipped in blackasphalt paint.

LJ- and LH-Series Iongspan joists and BLJ- andBLH-Series deep longspan joists are sprayed with a

J- and H-Series cold-formed joists (Bethspan) are red zinc chromate primer.

FIRE RESISTANCE OF BETHLEHEM STEEL JOISTSThe following fire ratings are the result of tests madein accordance with ASTM Standard Ell9. Thesetests were conducted in nationally recognized testinglaboratories. In addition to these constructions thereare numerous other floor and roof assemblies whichhave been tested. Complete lists of these tests arepublished by the National Board of Fire Underwritersand the Underwriters’ Laboratories, Inc.

(1) ONE-HOUR OR ONE-AND-ONE-HALF HOURFIRE RESISTANCE

(a)’ Top Slab: 2 in. reinforced concrete, or 2 in.pre-cast reinforced gypsum tile.

Ceiling: 3/4 in. Portland cement or sanded gypsumplaster on expanded metal lath.

(b)2 Top Slab: 2 in. reinforced concrete.

Ceiling: 5/s in. UL listed gypsum board.

(2) TWO-HOUR FlRE RESlSTANCE

(a)’ Top Slab: 21/ in. reinforced concrete, or 2 in.reinforced gypsum tile with i/4 in. mortar finish.

Ceiling: 2/4 in. sanded gypsum plaster on expandedmetal lath.

(b)a Top Slab: 2 in. reinforced concrete.

Ceiling: sg in. UL listed acoustical tile.

(c)a Roof Deck: 1 in. non-combustible insulationboard over 18-22 gage steel roof deck.

Cei l ing: 7/s in. vermiculite plaster on expandedmetal lath.

(3)’ THREE-HOUR FIRE RESISTANCETop Slab: 2ih in. reinforced concrete, or 2 in. rein-forced gypsum tile with i/ in. mortar finish.

Ceiling: 1 in. gypsum plaster, or 3/4 in. gypsum-vermiculite plaster on expanded metal lath.

(4)r FOUR-HOUR FIRE RESISTANCETop Slab: 2i/2 in. reinforced concrete, or 2 in. rein-forced gypsum tile with ‘/z in. mortar finish.

Ceiling: 1 in. gypsum-vermiculite plaster on expandedmetal lath.

1, “Fire Resistance Classifications of Building Constructions,”National Bureau of Standards Report BMS92, 1942.

2. Underwriters’ Laboratories, Inc., Design No. 2-I HR.3. Underwriters’ Laboratones, In:,, Design No. 31-2 HR.4. Underwriters’ Laboratories, Inc., Design No. RCI-2 HR.

RECOMMENDATIONS FOR HANDLING ANDERECTION OF BETHLEHEM JOISTS

Arrival-Check quantities against shipping noticeand notify carrier of any shortages.Check condition of material and notify carrier ofany damage.Report defects or shortages immediately.Be sure you have latest placing plans.Unloading-Handle joists with care.Do not dump off trucks.Unload by hand, or crane with slings through bendof middle web, at third points of chord. Use blockingif necessary to prevent local buckling of chord.

If transferring from car to truck, use long truck toprevent excessive overhang.

Storing-Near area where they will be used, placejoists vertically on blocking with tags all on one end.Cover joists to protect paint if they will be stored forany length of time.

Erection-Place joists by hand, or crane with slingsthrough bend of middle web, at third points of chord.When erecting longspans, do not release cables untilthe line of bridging nearest midspan is installed forspans up to 60 feet, until two lines nearest third pointsare installed for spans of over 60 feet to 90 feet, oruntil three lines nearest quarter points arc installedfor spans over 90 feet, and the ends of bottom bearingjoists have been restrained laterally.

Install all bridging and secure all ends of joists beforeapplying any construction loads. Joists are not capableof supporting their full design load until the top chordis stayed laterally by the floor slab or roof deck. Theattachment of the slab or deck shall be sufficient toprovide this lateral stability and spacing of attach-ments shall not exceed 36 in.

C o n s t r u c t i o n L o a d s - D o n o t p i l e m a t e r i a l o nbare joists.

Use 2-inch planks for light concrete buggy runways.Do not roll heavy buggies over joists.

After slab is set, area over beams and near walls sup-porting joists are preferable for temporary light loadstorage. Distribute loads well and do not overload.

Centering for Concrete(Must provide for lateral stability)

Slabform-See Slabform erection drawing.

Pipes and Conduits-Use space through webs.

DO NOT cut any part of any chord or web members.

Field Discrepancies-If any joist or accessory can-not be erected according to placing plans, we shouldbe notified immediately. We cannot be responsible forany held repairs or changes made without our consent.