US2413562A

US2413562A - Precast concrete members

Info

Publication number: US2413562A
Application number: US615265A
Authority: US
Inventors: Henderson Albert
Original assignee: WILLIAM P WITHEROW
Current assignee: WILLIAM P WITHEROW
Priority date: 1945-09-10
Filing date: 1945-09-10
Publication date: 1946-12-31
Anticipated expiration: 1963-12-31

Description

a o 15a I 45 INVENTJOR ATTORNEYS Ml, MIM# This is a continuation-in l The lack of such connecti lthe longitudinal reinforci rods to the pipelengths,

result in breaking the bo y crete .1. Beams with no web reinforcement Y Patented paesi,- 1946l YPRncAs'r CONCRETE Mamans Albert Henderson William P.

Edgewood, Pa. Witherow, y

assignor to Pittsburgh, Pa.

applicati@ september 1o, 1945, serial'No. 615,265

11 Claims.

This invention relates to precast building members kcomposed of concrete Vhaving reinforcing' rods or bars em-be to means for connecting a plurality of such membersdisposed adjacent each other.- 'f Y -part of my application, Serial No. 593,220, iiled May '11, 1945. The latter is in part a continuation of my application, Serial No. 480,620, filed March 26,1943-, for Precast concrete buildingzconnectionswhich 'is a continuation-impart y of my prior applications, Serial No.4 432,209, filed Precast concrete buil filed January 9, 1940.for

Precastconcrete build typeshave been propose as I am aware. vno sa'tisfa madeffor rigidly and pe jacent members together Concrete building. ing members of various d Vheretofore but, so far rmanently Y securing adons is probablythe reated use of precast struc- I'o meet J this requiremetal-pipe in certainv girders, beams, joists, engths are welded Vto son forthe'relatively Vlimi tural members heretofore. ment, IV embed :lengths of of thek members such -as and thelike. The pipe .l reinforcing rods embedded in the-members, thus imparting the necessary rigidity to the, connections. The pipe lengths may also have relatively short metal anchor rodsv welded thereto for embedding in the members,

v ng rods therein. y By thus welding the reinforcing rods and anchor instead of relying onV some otherv form of tie, su around'the'fpipe lengths, Iobtain an'extremely rigid `bond between the pipelengths and the concrete and avoid any danger of Vcrackingof the concreteV adjacent fthe pipe lengths which would nd therebetween. 'The importanceof this feature i'sreadily observed from the'table concrete under shear in terms of percentages of the ultimate compressive strength (Building Regulations for Reinforced Concrete, American Conglnstitute, Detroit, lows: Y ,l Per cent` and andwithout special anchorageof longitudinal.steel 1 V k 2 2. Beams with no web reinforcement but with f vspecial anchorage of longitudinal steel-- 3 rly designed webrein- Y ut special anchor- 3. VBeams. with prope Vorcement but Vwitho age of longitudinal steel 6 4. Beams with properly designed4 web r'einforcement. and with special anchorage of longitudinal steelr 12 Members. lembodying my invention are in the last,

extending parallel to l ch as looping the rods Michigan, 1941 yas v-fcldded therein and, in particular, Y

February 25, 1942, for ding, and Serial No. 313,067, Y

ctoryprovision has been infa building structure.

' In? a preferred embo pipe lengths are adapted/to jacent the ends load on one A rectangular pi l v ails and novel features of the inof allowable" stresses in' f* larger size;

Y A55 and .the ends of ka embers Withof the above groupings a y shear stress several times that of m out anchorage of th rods. Y Y A f The pipe lengths to which the rods are welded also afford means to positionA the'rods accurately in the'formsand main tionv whilel pouring concrete.

y I preferably em such as 11/2 A y provide the necessary connections, lengths'are preferably positionedin the members so that theircenters are substantially 21/2" from the nearest surface of thev me providing an adequatev thickness ofv protect the pipe lengths from re an I have invented'a ber having `means adapted to form permanent and rigid `tie between and the member or d corrosion.

diment, I provide a precast concrete member withlongitudi rods or bars and, adjacent the en ber, I embed pipe lengths ther Abarsandjvweld them thereto.

ds of the' memreceive tie means such as a bolt or dowel extendingY from an adjacent member. The reinforcing' bar yond the vrembedded pipe lengths'a closely adjacent 'the' extreme ends of the concrete members. This prevents the concrete adstress to'which the members are subjected when assembled in a Y lengths, being welded together, constitute a rigid frame or truss which is eiiective to transmit the member throu `thereof to a supporting member. u In some cases Des and ties may be used. @Further det vention will becomel apparent d ing complete description which companying drawing. In the d Figure lis of members splice plates thereto; Figure. 2is a sectionft line YII-II of Figure 1; A Figures 3 and 4 yare views si and 2 showin uring the followrawing,

aken 'along' the planeV of Figure 5 is a vertical v thereon; n

Figure isy a partial section taken plane of line VI'-VI of Figure 5;

Figure 7 is a view simil slightly modied splice plate: andV arg1 allowable e longitudinal reinforcing tain them rigidly in posi- 'A mber, thus]A concrete to novel type of concrete mem-A a simple yet.l

one member Y members adjacent thereto.

nalV reinforcing ein between the The bores of the4 s'ext'end bend terminate from breaking out ,under the building. 'I'he barsand pipe gh the reinforcing v,

refers to the aca transverse section through a pair i having precastreinforced concrete on each side thereof and secured4 l milar'to Figures 1 g members and splice plates oif'v section through a'col'umn` pairfof' girde'rs Vsupported u along `the y A ar toV Figure 6 showing The splice plates may "forcing bars I6 andI'I therein in pairs, one pair being adjacent each-4 side of the member. extend around the bars at. intervals and are welded to them. Pipe lengths I4 are embedded in the member I adjacent the ends. As shown in Figure 2, the pipe lengths are transverse to the bars and are welded thereto. The bars are Stirrups or cross ties I3 straight throughout their length and the ends extend beyond the pipe lengths I4 .to within a short distance ofthe extreme ends of the members I0, thus adequately reinforcing the concrete at the ends of the member beyond the pipe lengths.

Splice plates I5 are disposed on opposite sides of a pair of the members I0 arranged end to end. be of any suitable length. If the members I0 are 8" x 8", the splice plates are preferably 4" wide and 8 deep. The splice plates have upper and bedded near the ends hereof,-the pipe lengths extending transversely of the bars and welded thereto. The splice plates also have Stirrups or cross ties I9 welded to the bars. As inthe case lower longitudinal rein-v and pipe lengths I8 em.

reinforcing bars have cross ties welded thereto a intervals similar to the ties I3 and Isa.

The girders 24 differ from the members I0 and Ina in that the ends thereoLare notched as at 3| and the -ends ofthe upper reinforcing bars 32 are substantially flush with the extreme ends of the members and thus project somewhat beyond the wall of the notch 3|. of adjacent girders rare welded as shown at 33, access for the welding means being afforded by the recess formed by the notches JI The lower 32a are similar to the bars I2 of the members I0 and Illa and also may be welded at their ends as bars 32 are welded. A lfurther feature 'of the members 24 is the provisionA of anchor lbars $4 welded to the pipe lengths I4 extending inwardly therefrom and embedded lin the concrete.V v

Figure 6 furthershowsthe arrangement ofthe girders on the column. Speciilcallmit shows a 12"- wide girder ,24,resting Von an 8" wide col- Figure 7 is similar to Figure 6 showings. 16" wide girder l1 resting on a 12" wide column $8. The girder has lower reinforcing bars 39 arranged in pairsone bar ofv each pair extending on each side of each of the pipe'v lengths I4 being welded thereto.

of the'members I0, the bars I1 extendbeyond the pipe lengths I8. The center-to-center spacing of the pipe lengths I8 is such thatwhen the Pipe end-to-end are in alinement therewith the ends lengths I4 of Va pairof members I0 disposed ofthe members are in substantial abutment.

When the members to be connected end-to-end alined pipe lengths i4 and I8 to secure the splice plates and members firmly together.

` have been assembled with the splice plates as precastv concrete Figures 3 `and 4 show members -Illa and splicey plates IEa generally similar to those already described except that each member has intermediate reinforcing bars 22 in addition to the upper bars I I and lower bars I2. The splice plates also have intermediate bars 23. Stirrups or cross ties I9a extend around the bars I6, I'I and 23. The

' pipe lengths I4a in the mem-bers Ilia are disposed transversely of thebars and between adjacent pairs. The pipe lengths and the splice plates are similarly disposed, there being two pipe lengths in each end of each member Illa and in each end of each splice plates. Stirrups or cross ties Ha extend around the bars 'l I, I2and 22. When the members and splice plates arerassembled they may be permanently secured by rivets or bols 2Ia or tie bars may' be inserted through the pipe lengths and welded thereto at their ends.

Figure 5 illustrates a column 23' supporting the ends of a pair of girders 24 which are generally spirit of the invention or the scope of the apsimilar to the 'members III andIa. The column f has an integral base 25 rested on afield-east footing 26 with a layer of grout therebetween. Anchor bolts 21 embedded in the footing project upwardly through holes in the base 25 formed by pipe 1 lengths embedded herein and welded to Stirrups 29. The column has-longitudinal reinforcing bars 30 projecting above theupper end thereof and partially through the pipe welded to pipes I4. I mayll the space between bars 3D and pipe lengths I4 with grout. The bars lengths I4 embedded in the members 24. The ends of bars 30 may be` thereto.

the pipe1 lengths of 'each pair and yare welded It will be apparent that the invention 4provides members having means, whereby adjacent members ina construction may be easily yet permanently united. The reinforcing bars, beingl welded vto the pipe which the tie means pass, transmit '..they load applied to one member directlyy to the members connected thereto. The ends of the bars project-` ing beyond the pipe lengths prevent breakage of the concrete at the extreme ends of the members. The, connecting vmeans is. equally simple and effective in the case of splice plates for uniting membersabutting end-to-end as-in the v case of the column and girder combination in two alined girders rest on which the ends of the a single column.

Although I have a. fewy mod ications of recognized that changes y closed may be made `without illustrated and described but the invention, `it will'be in the constructions disde'parting from the pended claims. Y

1. In a building' construction a `plurality of precast reinforced concrete' members, said members includinga member having a tie extending therefrom and a second member having a longitudinal reinforcing bar embeddedtherein' land having a metalmemberclosely adjacent an end of said second member transversely disposed adjacent a side pi' said bar and being welded to 1 it, said metal member having a lbore receiving said tie, said second memberhaving another spaced, longitudinal reinforcing barwelded to The abuttingbars 32 .end of vvthe member 44 extendearoundv` lengths through said metal member, one of said bars extending beyond said metal member and being welded to a similar bar of another member in an axial position with respect to said secdnd member.

2. A building construction comprising a plurality of precast reinforced concrete members,

said members including a member having a tie means extending therefrom and a second member having embedded in the concrete thereof a frame comprising two spaced, longitudinally extending, primary reinforcing bars, said bars being straight for their entire length and haveY ing closely adjacent an end transversely disposed between them a metalmember, the ends of said bars projecting in a straight line beyond said metal member and terminating in proximity to the end of said second member, said metal member being welded to said two bars and having a bore therein receiving said tie means extending from said first-mentioned member.

3. A building construction comprising a plurality of precast reinforced concrete members, said members including a member having tie means extending therefrom and a second member having embedded therein a frame comprising two straight, spaced, longitudinally .extending, reinforcing bars, a pair of transversely extending metal members disposed between said bars closely adjacent one end of said secondmember, said bars extending beyond said metal members and terminating in proximity to the end of said second member, each metal member being welded to one of said bars and each having a bore therein receiving said tie means extending from said first-mentioned member. f

4. A building construction comprising a plurality of precast reinforced concrete members, said members including a member having a tie means extending therefrom and a second member in abutting engagement therewith having em' bedded in the concrete thereof a frame including two spaced apart, longitudinally extending, reinforcing bars and a metal member having a bore therein disposed transversely between said bars closely adjacent an end of said second member and welded to said bars, the extreme ends of said bars projecting beyond the metal mem-I ber, said metal member receiving said tie means.

5. A building construction as dened byclaim 4 characterized by the portion of said bars pro- Jecting beyond the metal memberhaving cross bars welded thereto, thereby reinforcing the extreme end portion of said second member.

6. A building construction comprising a plurality of precast reinforced concrete members, said members including a iirst member having a tie means extending therefrom and a second l member in abutting engagement with said rst member and having embedded in the concrete thereof a metal frame composed of two spaced apart, longitudinally extending, bonded to said concrete, and a metal member having a bore therein disposed transversely between said bars closely adjacent an end thereof and welded to said bars, said metal member receiving said tie means, said tie means serving to transmit from said iirst member a force acting on said metal member parallel to the longitudinal axis of said second member, and in either direction therealcng, the bearing of said meta] member on the concrete of said second member being shared between said bars by virtue of the welding of said metal member to said bars and the reinforcing barsA bond of the concrete of said second member to said bars.

7. A building construction comprising a plurality oi precast reinforced concrete members, said members including a first member having spaced tie means extending therefrom and a second member in abutting engagement therewith having embedded in the concrete thereof a metal frame composed of three spaced-apart, longitudinally extending, reinforcing bars, said bars being equally spaced from a side of said second member and including outer bars and an inner bar, and two metal members each having a bore therein disposed transversely between said bars closely adjacent an end thereof, said two metal members receiving said tie means" and being welded to said inner bar and each metal member being welded to one of said outer bars, each metal member being spaced the same distance from one end of said second member, thereby tying the three bars together and preventing lateral movement thereof when said tie means exerts a force parallel to said bars in either direction therealong.

8. A precast reinforced concrete structural unit comprising an elongated mass of concrete having embedded therein a metal frame including two spaced-apart, longitudinally extending, reinforcing bars, and a metal member having a bore therein being transversely disposed between said bars closely adjacent an end of each bar, said metal memb r being welded to at least one of said bars.

9. A precast reinforced concrete structural unit comprising an elongated mass of concrete having embedded therein a metal frame including three spaced-apart, longitudinally extending, reinforcing bars and two metal members each having a bore therein, said metal members being transversely disposed between said bars closely adjacent an end thereof, said bars being equally spaced from a side of said unit and including outer bars and an inner bar, said two metal members being equally spaced from one end of said unit and each metal member being welded to one of the outer bars and to the inner bar.

10. A building construction comprising a plurality of precast reinforced concrete members, said members including a first member having a tie means extending therefrom and a second j first member extending into said bore in said anchor.

4 11. A precast concrete structural unit comprising an elongated mass of concrete having a compression area and a tension area, two spaced, longitudinal, reinforcing bars being embedded in the tension area of said unit, a metal anchor having a bore therein being embedded in the unit and extending into the tension area and the compression area adjacent an end of said unit, said anchor being disposed transversely to and being welded to an end of each bar.

ALBERT HENDERSON.