US3513610A - Concrete structural member,framework structure,and casting method - Google Patents

Description

May 26, 1970 D. K. DEVONPORT 3, ,6 CONCRETE STRUCTURAL MEMBER; FRAMEWORK STRUCTURE AND CASTING METHOD Filed Feb. 8, 1967 3 Sheets-Sheet 1 I INVENTOR.

DEREK KENNETH DEVONPORT May 26, 1970 D. K. DEVONPORT CONCRETE STRUCTURA 3,513,610 L MEMBER; FRAMEWORK STRUCTURE AND CASTING METHOD Filed Feb. 8, 1967 3 Sheets-Sheet 2 Ila l3 m; I /7 0 l9 /4 {5 ll /60 j; w k E /6 V6) 2/ 27 INVENIOR. DEREK KENNETH OEVO/VPORT May 26, 1970 D. K. DEVONPORT CONCRETE STRUCTURAL MEMBER FRAMEWORK STRUCTURE AND CASTING METHOD 3 Sheets-Sheet 5 Filed Feb. 8, 1967 IIIA'UIIIIIIIIIIIIIIIIIL INVENIOR.

VIIIIlll/llllllll 'lllllllllllllllllll DEREK KENNETH DVONPORT United States Patent land Filed Feb. 8, 1967, Ser. No. 614,631 Claims priority, application Great Britain, Feb. 26, 1966, 8,552/66 Int. Cl. E04b 1/00, 5/00, 7/00 US. Cl. 52283 3 Claims ABSTRACT OF THE DISCLOSURE A reinforced concrete structural member, such as a pillar or beam, has a cast-in metal connection element which is contained wholly within the cross-section of the member and has a face, whereat it is pierced with connection holes, exposed at an exterior surface of the memher. In the case of a pillar, the connection element is cast-in at a required height and has flanges, with their faces exposed, connected by webs within the concrete and pierced with bolt holes. In the case of a beam, the latter has a rebate at its end providing a horizontal undersurface at which the said face of the element is exposed. In a framework structure built up of these pillars and beams, each beam end is secured to a pillar by means of a beamsupport bracket having a flange bolted to a flange of the connection element of the pillar and having a web bolted to, and underlying, the exposed face of the connection element of the beam. In manufacture of such a structural member, the latter is cast in an open trough-like mould of adjustably-determined length in which the connection element is disposed, at the required location, in face contact with a wall of the mould.

Cross references to related applications Reference is made to British patent application No. 8,552/ 66 of Feb. 26, 1966, Trent Concrete Limited, from which priority is claimed.

Summary of invention This invention comprises improvements in and relating to precast, reinforced concrete structural members, primary structural members of elongated form and, specifically, uprights such as pillars or columns and transverse members such as beams, which may be built up into a skeleton framework for civil engineering structures (for example, for buildings) on the site.

The invention provides a reinforcedprecast concrete structural member incorporating, as an integral cast-in component, a non-protruding metal connection element having a face exposed at an exterior surface of the member and being provided at said exposed face with a plurality of connection holes for use in connecting that structural member to another structural member. In the application of the invention to a structural member of elongated form, the said face of the connection element may be exposed at a longitudinal exterior surface. In the case of a column or pillar such a connecting member may be provided at any desired location, or locations, in the height thereof, the face of said element being exposed at an exterior side surface of the column or pillar. The element may have a plurality of such faces exposed one at each of a plurality of exterior surfaces of the member. The element may have a plurality of such faces disposed at angles to one another (and thus, in the case of a column or pillar, providing for the connection of beams dis posed at angles to one another) and/or parallel to one another.

3,513,610 Patented May 26, 1970 if ce In the case of a beam the element may be located at the end of the beam with its said face exposed at an exterior surface to the beam, preferably an underneath surface.

It is an important feature of the invention that the element is contained wholly within the cross-section of the structural member at the location whereat it is incorporated therein.

The invention also provides a structure built up from reinforced precast concrete structural members, comprising upstanding members and transverse members having their ends secured to the upstanding members at side surfaces of the latter, wherein at each joint between an upstanding member and the end of a transverse member the upstanding member has, as an integral cast-in component, a metal connection element having a face exposed at, but not protruding from, the said side surface, and the transverse member has at its end, as an integral cast-in component, a metal connection element presenting an exposed face, and the said connection elements are rigidly secured together by being bolted to a metal support member interposed between said exposed faces.

The invention further provides in the manufacture of a precast reinforced concrete structural member by casting it in a horizontal mould of open trough-like form, the steps of predetermining the length of the structural member by partitioning off a desired length of the mould by end closure members at least one of which is adjustable along the mould, disposing wholly within the trough-like interior of said length of the mould, at a location which is adjustably predetermined with regard to said closure members, a metal connection element having a part which protrudes into the mould interior so as to be cast into the structural member and a face which is presented against a wall of the mould and is provided with a plurality of connection holes, and casting the concrete in the mould whereby said connection element forms an integral component of the structural member with its said face exposed at a face of the latter. It will be appreciated that this method of manufacture not only permits a standard mould to be adapted to cast structural members of any desired predetermined length (or to a plurality of such members, each of predetermined length) but also permits the location of the connection element or each of them to be adjustably predetermined in relation to the length of each structural member because the connection element is wholly contained within the cross section of the interior of the mould. By way of contrast it may be pointed out that were the connection element to protrude from a side face of the structural member, as for example to form a bracket on which the end of a beam may be supported, the wall of the mould (the expression wall includes a base) would have to have an aperture or recess to receive this protruding part and the mould would only be capable of casting structural members having the connection element at a fixed location.

In order that the invention may be better understood reference will now be made to the accompanying drawings, in which:

FIG. 1 is an exploded view of a portion of a pillar or column according to this invention and of the adjacent end of a beam;

FIG. 2 is a sectional view on a larger scale of a portion of the column or pillar with an attached beam supporting member;

FIG. 3 is a sectional elevation showing the manner in which one form of beam according to this invention is fixed to the column or pillar;

FIG. 4 is an exploded view similar to FIG. 1, but showing an alternative construction of beam;

FIG. 5 is a perspective view showing an alternative construction of column or pillar;

FIG. 6 is a perspective view of part of a framework structure built up of pillars and beams according to this invention;

FIG. 7 is a cross-section through a mould for casting a pillar;

FIG. 8 is a diagram illustrating the reinforcement cage of the pillar;

FIG. 9 is a longitudinal section through a portion of a mould arranged for casting a beam such as is shown on FIG. 1;

FIG. 10 is a cross-section through this mould;

FIG. 11 is a longitudinal section through a portion of a mould for casting a beam such as is shown in FIG. 4; while FIG. 12 is a sectional plan thereof.

The pillar 10 shown in FIG. 1 has, at a predetermined location in its height, or at each of a plurality of such locations, a cast-in metal connection element indicated generally 11. This element is of H-section being cut from rolled steel joist and having opposed parallel flanges 11a connected by a central web 11b. It is wholly contained within the cross section of the column at this location, whereat opposed vertical surfaces of the column are recessed as at 12. The outer faces of the flanges 11a are exposed at, and are flush with, the surfaces of these recesses 12. Each flange 11a is pierced with a plurality of bolt holes. In FIG. 1 the centres of these bolt holes are shown in conventional manner by crossed lines, and they are shown as being four in number. At the inner end of each bolt hole a nut is welded to the inner face of flanges 11a. In FIG. 2 a representative bolt hole is shown at 13 and its nut at 14. This nut is capped by a cap 15 (desirably injection moulded from synthetic resin) to prevent concrete entering the bolt hole when the column or pillar is being cast.

A metal beam-supporting bracket 16 is bolted to the exposed face of one or each flange 11a. As shown in FIGS. 1 and 2 this bracket 16 is of T-shaped section having a vertical flange 16a and a horizontal web 16b, the latter being desirably stayed by a welded-in gusset plate 16c. The flange 16a is pierced with bolt holes for registering with holes 13. In FIG. 1 the position of these bolt holes is indicated in conventional manner and in FIG. 2 a representative bolt hole is shown at 17.

A friction-grip bolt 18 is entered into each pair of registering bolt holes 13, 17 and is screwed into the nut 14 as shown in FIG. 2. This bolt is provided beneath its head with two washers 19, 20. Washer 19 is a spring washer having protruding spring tabs which are engaged by washer 20. The bolt is tightened until the gap between the two washers has been reduced to a predetermined width. This ensures a minimum tensile force in the bolt and that the shear load applied to the joint by weight imposed on the web 16b is not resisted merely by the bolts in shear but is largely resisted by the frictional engagement between the flanges 11a, 16a.

The horizontal web 16b of member 16 is pierced with horizontal slots. In FIG. 1 the location of these slots is shown in conventional manner and a representative slot is shown at 21 in FIG. 2.

It is desirable that the member 16 shall be bolted in position at the factory where the pillar is cast.

FIG. 1 shows the adjacent end portion of a precast and prestressed reinforced concrete beam 22. A metal connection element indicated generally at 23 is cast into each end of this beam. This element consist of a tubular metal member 23a of a box section extending a short distance lengthwise of the beam and a horizontal metal plate 23b welded to the underside of member 23a. Surrounding and desirably welded to member 23a there is a metal frame 23c within which the prestressing wires (see 50, FIGS. 9 and 10) extend.

The end of the beam is stepped or rebated as at 24 and the undersurface of plate 23b is flush with, and exposed at, the horizontal surface of the rebate. The length of 4 plate 23b is less than the width of the beam and it will therefore be appreciated that the connection element 23 and in particular plate 23b is wholly contained within the cross section of the beam.

The plate 23b is pierced at opposite sides of member 23a with bolt holes for registering with the slots 21 in the web 16b of bracket 16. In FIG. 1 the location of one of these bolt holes is indicated in conventional manner. In FIG. 3 a representative bolt hole is shown at 25 and it will be seen it leads to a nut 26 which is welded to the upper surface of plate 23b. A fixing bolt 27 is screwed through the web 16b into this nut.

Thus the end of the beam 22 is securely bolted to the pillar 10 and this operation is carried out at the site where the framework is erected. The slots 21 allow for manufacturing tolerances in the length of the beams and for minor discrepancies in the spacing between adjacent columns that are to be connected by the beams.

The end of the beam registers with the recess 12 in the face of the column 10 but there is a variable gap between the end face of the beam and the face of this recess. As shown in FIG. 3 grouting 28 is introduced into this gap to fill it and also to occupy the step 24 in the underside of the beam and to bury the bolts 27 and adjacent metal parts. Desirably before the grouting operation a link 29 of bent metal rod or stout wire is introduced into the gap so as to span the protruding web 16b and its ends are cranked inwards into the rebate 24.

FIG. 4 shows an alternative arrangement in which the beam 30 is of L-section. Instead of the horizontal plate 23b there is provided, in the connection element 23, an L-section metal member 31 having a horizontal flange 31a and a vertical web 31b. The upper face of flange 31a lies in the same plane as, and is partly exposed at, the upper face of the horizontal part 30b of beam 30 and the upper face of flange 31a is welded to the underside of member 23a. Its front edge is coincident with the end face of the vertical part 30a of the beam; one side edge is spaced inwards from the side face of part 30b of the beam. The outer face of web 31b is coincident with, and is exposed at, the end face of rebate 24. The bolt holes are formed in, and the nuts welded to, flange 31a. One or more bolt holes may register with the base of member 23a which is therefore drilled to accommodate the nut; the latter is suitably blanked off to prevent concrete from entering it. The bolt hole (or each thereof) in the exposed part of flange 31a is desirably countersunk to ac commodate a countersunk nut.

The rear face of web 31b may be welded to a T-section member 32 having a web 32a welded to the side of member 23a.

FIG. 5 shows an alternative construction of pillar 10 in which each of its four faces is recessed as at 12 and in which the cast-in metal element 11' has four flanges at right angles one exposed at each face of the recessed part of the pillar. This permits four beams to be connected to the one pillar so as to extend at to one another.

FIG. 6 illustrates a structural framework, for example for a building, built up from pillars 10 and beams 22, 30 according to this invention. There is a plurality (shown as 3) of parallel rows of the pillars 10, the pillars in the outermost rows being connected at appropriate levels by beams 30 and those in the centre row by beams 22, the pillars at the end of the rows being likewise connected by beams 30. The pillars in each intermediate row need not necessarily be in line with those in the outer rows. The beams 22 of the inner rows can be at different levels from the beams 30 of the outer rows, and it is intended that the beams 30 of the outer rows shall support flooring components (not shown).

In casting a structural member according to this invention, use is made of a horizontal mould of trough-like form which is partitioned off into desired lengths according to the required lengths of the structural members by closure members or partitions which can be adjusted along it and provision is made for locating the connection element at the desired lengthwise position in each partitioned-off length.

Thus in FIG. 7 there is a mould of trough-like form having base a and opposed sides 35b which can be adjustable for spacing in any suitable manner. This mould is divided up into the required lengths by closure members or partitions 36 through which the main reinforcements 37 of the reinforcement cage 38 (FIG. 8) extend. In this instance the connection element 11' is shown as having three flanges 11a two of these flanges being parallel with one another and the third at right angles thereto. At least one locating boss 40 is attached to the base 35a of the mould for example by an impact adhesive. This serves to locate lengthwise of the mould a plate 41a which is disposed on the base 35a, and, in the sense that it forms one of the recesses 12, constitutes a wall of the mould. This plate supports the element 11' and locates it lengthwise of the mould by reason of bosses 42 which enter the bolt holes 13 in the lower flange of the element. A similar plate 41b is disposed against the mould wall 35b and is itself located from the vertical flange of the element 11' by locating pins 42, and a third plate 410 rests on the top flange and is similarly located.

When the mould has thus been set up with the reinforcement cage 38 of the element in position, concrete is poured into the mould and struck off level with the top of the latter.

Referring to FIGS. 9 and 10, at each division in the length of the mould 35 there may be a pair of closure members 36 with a spacer 45 between them. In each part of the mould there is an angle member 46 which provides the rebate 24 of a beam 22, FIG. 1, and to which the plate 23b of the element 23 is temporarily bolted by at least one bolt 47. Additionally the element 23 may be further supported by having a lug 48 on the box-section member 2311 temporarily bolted at 49 to the closure member 36. The pre-stressing wires 50 are threaded through the closure members 36 and through the member 46. Member 23a is pre-filled in the sense that prior to the connection element being introduced into the mould, it has concrete cast into it to fill its interior, any nut presented at its interior being suitably blanked off.

Turning now to FIGS. 11 and 12, the L-section beam 30 shown in FIG. 4 is cast on its side with the rebate 24 and part 30b vertical and the part 30a horizontal. The rebate is formed by means of an L-sectioned member 51 which is positioned at one side of the mould against the dividing plate 36 and is attached to the plate by means of at least one bolt 52. The connection element 23' is temporarily bolted to this member 51 with the flange 31aagainst the vertical face of the latter by a bolt 53 which screws into a blanked-oft nut in the interior of the tubu-- lar member 23a and is further located by a tapered pin 54 which enters a hole in said flange.

What we claim is:

1. A framework structure, for a building, of the kind 6 comprising precast concrete pillars and precast concrete beams connecting them with a joint between each end of each beam and a pillar, wherein:

(a) each pillar comprises a cast-in non-protruding metal connection element having at an intermediate region in its height a cast-in non-protruding metal connection element which is wholly contained within the cross-section of the pillar at said region and comprises a plurality of flanges and web-means connecting them, which flanges have exterior vertical faces exposed one face at each of a plurality of side faces of the pillar but not protruding from said side faces and each of which flanges is pierced with bolt holes at its said exposed face,

(b) each beam has, at each end, a cast-in metal connection element having a horizontal face exposed at the undersurface of the beam, which face is pierced with bolt holes, and

(c) each joint comprises a metal support bracket having a flange and a protruding web each pierced with bolt holes, the flange being bolted to a vertical face of the connection element of the pillar with the connection element of the beam resting on and bolted to the protruding web.

2. A precast concrete pillar having, at an intermediate region in its height, a cast-in non-protruding metal connection element which is wholly contained within the cross-section of the pillar at said region and comprises a plurality of flanges and web-means connecting them, which flanges have exterior faces exposed one face at each of a plurality of side faces of the pillar and not protruding from said side faces and each of which flanges is pierced with bolt holes at its said exposed face.

3. A pillar according to claim 2, wherein said element has two of the said flanges the said faces of which are exposed at two opposite side faces of the pillar.

References Cited UNITED STATES PATENTS 1,205,465 11/1916 Maguire et a1 52723 1,796,048 3/ 1931 Robinson 52601 2,208,814 7/19'40 Peabody 52-601 1,086,866 2/1914 Snyder 52260 2,115,949 5/1938 Gurber 52283 2,994,415 8/1961 Halle 52283 3,261,135 7/1966 Knabe 52283 XR FOREIGN PATENTS 118,058 8/1918 Great Britain. 847,298 9/ 1960 Great Britain.

FRANK L. ABBOTT, Primary Examiner I. L. RIDGILL, JR., Assistant Examiner US. Cl. X.R. 52648, 587, 723

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