US3801061A

US3801061A - Form panel with grouting plug core

Info

Publication number: US3801061A
Application number: US00159151A
Authority: US
Inventors: J Holt
Original assignee: Burke Concrete Accessories
Current assignee: Burke Concrete Accessories
Priority date: 1969-04-30
Filing date: 1971-07-02
Publication date: 1974-04-02
Anticipated expiration: 1991-04-02

Abstract

An apparatus and method for constructing a concrete form comprised of a pair of form panels arranged in opposed spaced relationship and secured against movement relative to each other by tie rods extending therebetween. The apparatus comprises conical grouting cores secured to the panels independently of the rods to slidably receive the rods and permit their extension through the panels from the outer side of one of the panels, and waler brackets mounted on each of the panels for selective gripping engagement with the ends of the rods to prevent movement of the panels toward and away from each other. The brackets are provided with hinged jaw-like elements which are movable to effect selective engagement and disengagement of the brackets with the rods. When disengaged, these elements permit free slidable movement of the rods relative to the brackets. The method is directed to the construction of a concrete form by a ''''feed through system'''' wherein tie rods are fed through a pair of opposed panels and grouting cores secured thereto from the outer side of one of the panels. In the method, once the rods are fed through the panels, they are secured against axial movement relative thereto to maintain the panels in opposed spaced relationship. In an alternative embodiment, the apparatus and method is concerned with an arrangement wherein bushing inserts are secured to the panels in place of the conical grouting cores and cores or other sealing elements carried by the tie rods are cooperable with these inserts.

Description

United States Patent 11 1 [111 3,801,061 Holt Apr. 2, 1974 FORM PANEL WITH GROUTING PLUG [57] ABSTRACT CORE An apparatus and method for constructing a concrete [75] Inventor: Jack Holt San Bruno, Calif form comprised of a pair of form panels arranged in opposed spaced relationship and secured against Asslghee? Burlfe Concrete fhccessm'ies -a movement relative to each other by tie rods extending Burhhgame: Cahftherebetween. The apparatus comprises conical grout- [22] Filed: July 2 971 ing cores secured to the panels independently of the rods to slidably receive the rods and permit their exl PP 159,151 tension through the panels from the outer side of one Rdated Application Data of the panels, and waler brackets mounted on each of [60] Division of SCI. No. 824,359, April 30, 1969, Pat. the panels for Selectve gnpping engagement the 3693931, continuatiomimpan of ends of the rods to prevent movement of the panels 683,558, Nov 16, 1967, abandoned toward and away from each other. The brackets are provided with hinged jaw-like elements which are 52 [1.5. Ci. 249/190, 249/217 movable to effect Selective engagement and disen- [51] Int. Cl. E04g 17/12 gagemeht of the brackets with the rodswhen disen- [58] Field. of Search 249/40, 42, 43, 190, 191, gaged, these elements Permit free Slideble movement 249 2 3 2 27 1 9 of the rods relative to the brackets. The method is directed to the construction of a concrete form by a [56] References Cited feed through system wherein tie rods are fed UNITED STATES PATENTS through a pair of opposed panels and grouting cores secured thereto from the outer side of one of the pani 3 618 887 11/1971 Erlks l'i l: 1:31.. 249 40 P they are h against movement rela 3:0206I6 2/1962 Marpe A v 249/40 tive thereto to mamtam the panels in opposed spaced I336IO3O 4/1920 Gammeter 271/189 X relationship. In an alternative embodiment, the appa- 3,437,306 4/1969 Gates 249/43 rattle and method is Concerned with an arrangement 1,027,565 5/1912 Ramage. 277/189 X wherein bushing inserts are secured to the panels in 2,383,570 8/1945 Sellen 277/189 X place of the conical grouting cores and cores or other 3,273,848 9/1966 Allen et a]. W sealing elements carried the tie rods are cooperable FOREIGN PATENTS OR APPLICATIONS with these inserts- 1,534,955 7/1969 Germany 249/43 4 Claims, 10 Drawing Figures Primary Examiner-Robert D. Baldwin Attorney, Agent, or FirmNaylor, Neal & Uilkema PATENTEDAPR 2 m4 SHEET 2 UF 3 INVENTOR.

JA 6K A. HOL r W MK ATTORNEYS This application is a division of application Ser. No. 824,359, filed Apr. 30, 1969 now US. Pat. No. 3,693,931 issued Sept. 26, 1972, which application in turn is a continuation-in-part of my application Ser. No. 683,558, filed Nov. 16, 1967, now abandoned.

The present invention relates to the art of constructing concrete forms and, more particularly, is directed to the construction of such forms from panels arranged in opposed spaced relationship and secured against movement relative to each other by tie rods.

In the prior art, various arrangements have been provided to construct concrete formsfrom panels held in opposed spaced relationship by tie rods extending therebetween. The most conventional of these arrangements simply provide for the mounting of the rods to the inner side of one of the panels and then for the assembly of the other panel over the rods. With arrangements of this type, spacers are mounted on the rods for abutting engagement with the inner surfaces of the panels and waler brackets are employed to force the panels against the spacers. Such arrangements have the disadvantage that the panels must, in effect, be assembled around the rods. This disadvantage is particularly acute when large difficult to handle gang form assemblies are employed.

To avoid the disadvantages inherent with prior art arrangements of the foregoing type, efforts have also beenmade to provide arrangements wherein tie rods may be fed through opposed panels from the outer side of one of the panels and then secured in place. While these efforts have met with some success, the arrangements employed therein also possess certain inherent disadvantages, One of the disadvantages is that the tie rods used in the arrangements must be formed with looped or notched ends, rather than the more conventional hot-upset ends. Another disadvantage of these arrangements is that they have been incapable of effectively providing sealing and grouting cores around the rods employed therein. Such cores are necessary to prevent leakage of fluid concrete around the rods and permit architectural finishing after the panels are removed.

In summary, the present invention may be said to reside in a concrete form construction and method of fabricating the same. The construction comprises, as its basic elements, a pair of form panels disposed in opposed face-to-face relationship and having transversely aligned apertures extending therethrough. The apertures in at least one of the panels have tubular grouting cores sealingly secured thereto and extending laterally toward the other of the panels. These cores slidably receive tie rods which extend between the panels and through the aligned apertures therein. Waler brackets mounted on the respective panels permit the rods to be inserted from a position to one side of one of the panels and, upon placement of the rods, are selectively operable to maintain the rods against axial movement relative to the panels.

In its more specific aspects, the invention is concerned with the specific construction of the grouting cores and the waler brackets. The cores are adapted to be secured to the panels independently of the rods and, together with cooperating sealing structure provided on the rods, to seal the openings in the panels to the flow of fluid concrete. Each waler bracket comprises a base member adapted to be fixed to the panel on which it is mounted and selectively operable gripping structure associated with the member to apply tension imparting force to a rod while restricting its axial movement in either direction.

An alternative embodiment of the invention employs bushing inserts secured to the panels in place of the tubular grouting cores and cores or other sealing elements carried by the tie rods for cooperation with the inserts.

It is, accordingly, a principal object of the present invention to provide a concrete form construction .and method of fabricating the same wherein tie rods may be passed through opposed panels from a position disposed to one side of one of positioning of the tie rods in this manner.

Still another object of the invention is to provide architectural grouting cores which may be securely mounted to form panels and permit the substantially unrestricted axial movement of tie rods therethrough.

Yet another object of the invention isto provide a bushing insert adapted to be secured within the tie rod opening of aform panel to seal and protect the edges of the opening and act as a guide and bearing element for a grouting core or other sealing element carried by a tie rod extended through the opening.

These and other objects and the specifics of the invention will become more apparent whenlviewed in light of the accompanying drawings, wherein:

FIG. '1 is a perspective view illustrating the waler bracket and the panel secured grouting core of the invention attached to a concrete form panel having walers extending transversely thereacross, with the walers and form panel illustrated in partial section;

FIG. 2 is an exploded perspective view illustrating an entire concrete form construction employing form panels and hardware of the type shown in FIG. 1, with the form panels and walers incorporated therein illustrated in partial section;

FIGS. 3 and 4 are sectional views taken on the planes designed by lines 3-3 and 4-4, respectively, of FIG.

FIG. 5 is an exploded perspective view illustrating the components of the waler bracket;

FIG. 6 is a top plan view of the panel secured grouting core;

FIG. 7 is an exploded perspective view illustrating a concrete form construction incorporating the bushing inserts of the invention and a feed through tie rod carrying grouting cores cooperable with the inserts, with parts of the walers and form panels broken away and THE FIGS. 1 To 6 CONSTRUCTION Referring now to FIG. 1, a form panel is therein designated by the numeral 10 and is shown as having

walers

12 and 14 fixed thereto to either side of an aperture 16 (see FIG. 3) extending therethrough. This overall arrangement provides for bracing of the panel and the extension of tie rods therethrough. While only one aperture and the walers cooperating therewith are illustrated, it is to be understood that the panel would be provided with a plurality of such apertures between the

walers

12 and 14 and that other similarly provided walers would be fixed to the panel where necessary.

The walers l2 and 14 have a waler bracket, designated in its entiretyby the numeral 18, mounted thereon. The bracket 18 comprises a base member 20 fixedly secured in overlying relationship to the walers by nails 22 and a tie rod gripping jaw 24 pivotally mounted on the base member for selective slidable movement thereover. Pivotal mounting of the jaw is provided by post 26 secured to the member 20 and extending through an opening 28 (see FIG. 4) provided therefor in the jaw.

In the embodiment illustrated, the base member 20 is fabricated of a pair of sheet metal plates fixedly welded together and having a central aperture 30 extending therethrough. When the bracket is mounted, the aperture 30 is positioned in alignment with the aperture 16. In addition to the aperture 30, the base member 20 is provided with apertures 32 for receipt of the nails 22, a pair. of outstanding detent protrusions 34 and 36, and an outstanding stop protrusion 38. The protrusions 34 and 36 are releasably engageable with the jaw 24 to selectively retain it in the positions illustrated in FlGS. l and 2, respectively. The protrusion 38 is positioned to abut with the jaw when it is engaged with the protrusion 34.

The detailed construction of the jaw 24 may best be seen from FIG. 5. There it can be seen that the jaw is comprised of a detent member 44 disposed for slidable engagement over the outer surface of the member 20 and a retention member 46 fixed over the detent member. in the preferred embodiment, these members are fabricated of sheet metal and fixedly secured together.

by spot welds 48 therebetween. Aligned apertures through the members define, together, the opening 28. in addition to these apertures, the member 44 is provided with

apertures

50 and 52 and an arcuate slot 54 opening through one edge thereof and extending thereacross in concentric relationship to the opening 28. The slot 54 is aligned with the aperture 30 for passage thereover and around a tie rod extending therethrough.

The

apertures

50 and 52 are disposed in alignment with the protrusions 34 and 36, respectively, for passage thereover and releasable engagement therewith. The latter engagement provides for the aforedescribed retention of the jaw in the alternative positions illustrated in FlGS. l and 2.

The base member 20 and detent member 44 cooperate in much the same manner as a conventional waler bracket in that they provide for the engagement of a tie rod end and the application of tension imparting force thereto. To facilitate this operation, the member 44 is provided with an inclined ramp portion 56 around the slot 54 and an upstanding ear 58. The ramp portion 56 diverges outwardly relative to the base member adjacent the open end of the slot 54 and terminates in a length substantially parallel to the base member at the closed end of the slot. The ear 58 is simply intended as a striking abutment to provide for the convenient driving of the detent member with the hammer.

portion 60 disposed above and in spaced relationship to the portion 56 and

peripheral portions

62 and 64 secured directly to the member 44 by the spot welds 48. The box portion 60 is of generally arcuate open ended configuration and flared out at 60a to facilitate the passage of a tie rod therebeneath. The opening 28 extends through the portion 64; and a riveted over end on the post 26, together with washers 66 around the post, function to maintain the jaw against lateral movement realtive to the base member 20.

The manner in which a tie rod is engaged by the waler bracket 18 and the construction of the tie rod and the grouting core cooperating therewith may be seen from FIG. 3. In this figure, the tie rod and grouting core are designated, respectively, by the

numerals

68 and 70. While only one end length of the tie rod 68 is illustrated in FIG. 3, it is to be understood that both end lengths of the rod are similarly constructed for extension through a form panel and engagement by a waler bracket.

The rod 68 is of the snap-tie type in that its end lengths are designed to be broken away by the application of torque thereto. The end lengths and the intermediate length of the rods are designated by the

numerals

72 and 74, respectively. These lengths are integrally formed and provided with adeformed enlarged collar-like portion 76 therebetween. It is at the juncture of this collar portion and the length 74 that the end lengths are designed to break away. The rod is also provided with crimped portions 78 in the lengths 72 adjacent the portions 76 and enlarged terminal end portions 80 of the hot-upset type at the distal ends of the lengths 72. Washers 82 are concentrically received around the rod and held against axial movement thereover by abutment with the

portions

76 and 78. Each of these washers is designed to fit closely within the grouting core cooperating therewith to seal the core to the flow of fluid concrete therethrough, while permitting slidable movement of the rod within the core.

The core is of integral tubular configuration and defines a passage 84 extending axially therethrough. The internal end lengths'of the passage 84, designated by the

numerals

86 and 88, are of hexagonal configuration for turning engagement by an Allen wrench. The body of the core is comprised of a truncated conical portion 90 and a cylindrical dowel-like portion 92. The portion 90 diverges towards the portion 92 and terminates in a planar base surface 94 forming a juncture therewith. The portion 92 isformed with self-threading external screw threads 96 for engagement with the aperture 16. When assembled as shown in F l0. 3, the por tion 92 is threaded into engagement with the aperture 16 so as to tighten the base surface into sealed engagement with the panel 10.

[t is here noted that the rods 68 and the washers 82 mounted thereon are dimensioned to pass, in their entirety, through the aperture 30 in the base member of the waler bracket and the passage 84 in the grouting core. Thus, the rods 68 may be inserted-into the position shown in FIG. 3 from either side of the panel 10. The cross sections of the lengths 72 and headare such that, once the rod is positioned, the jaw 24 may in abutting engagement with the undersurface of the head 80. The depth of the head 80 is such that, when the undersurface thereof is engaged with the outermost length of the ramp portion 56, the outer surface thereof is in proximate abutting engagement with the underside of the box portion 60. This overall interrelationship may be seen from FIG. 3. It should be appreciated that the distance between the ramp portion 56 and box portion 60 is sufficient to permit the head 80 to pass freely to the position shown in FIG. 3.

THE FIG. 1 TO 6 METHOD The method of employing the structure of FIGS. 1 to 6 for the construction of a concrete form may best be seen from FIG. 2. In this figure, two form panels are shown in the process of being assembled in spaced opposed face-to-face relationship. The forward panel in this figure and the components mounted thereon are those of FIG. 1. The rearward panel, designated by the numeral 10a is a mirror image of the panel 10. The walers on the latter panel are designated by the

numerals

12a and 14a, respectively. The panel 10a and the

walers

12a and 14a are provided with hardware identical to that on the panel 10 and the walers l2 and 14. This hardware, to the extent that it is illustrated, is designated by numerals corresponding to those used in the foregoing discussion.

To construct a form by the method illustrated in FIG. 2, the following steps are sequentially carried out:

1. The

panels

10 and 10a are disposed in stacked face-to-face relationship and aligned apertures (16) are drilled therethrough.

2. The walers and the waler brackets are securedto the respective panels.

3. The grouting cores 70 are securely screwed into the apertures.

4. The panels are disposed in opposed face-to-face relationship, as illustrated in FIG. 2, with the apertures in alignment.

5. The rod is passed through the panels from one side of one of the panels (see the arrow line in FIG. 2).

6. The ends of the rods are engaged by the gripping jaws on the respective waler brackets to secure the rods against axial movement relative to the panels and maintain the panels in opposed spaced relationship. While the FIG. 2 illustration and the foregoing description are directed to the positioning of only one tie rod, it is to be understood that in actual practice a plurality of rods would be similarly placed between the opposed form panels.

Once a concrete form is thus constructed, concrete is poured between the panels and allowed to set. After the concrete has set, the panels may be readily removed by releasing the gripping jaws of the waler brackets from the tie rods and pulling the panels away from the formed concrete. During the latter operation, the grouting cores are pulled from the form concrete with the panels and, thus, clean grouting pockets are provided. After removal of the panels, the end lengths of the tie rods may be readily broken away by the application of torque thereto. It should be understood that, if desired, the end lengths may be broken away before actual removal of the form panels.

The removed panels may be readily reused by simply repeating the steps of disposing the panels in opposed face-to-face relationship with the apparatus therein aligned and passing and securing a tie rod or rods between the panels. In this operation, the tie rods are the only elements which need be renewed. The panels, walers, waler brackets and grouting cores are all reused, since they remain secured together when the panels are removed from a previous pour of set concrete. In addition to facilitating their reuse, the secure mounting of the grouting cores has the advantage that it functions to prevent the leakage of fluid concrete between the cores and the panels.

THE FIG. 7 TO 10 CONSTRUCTION The form panels, walers, waler brackets andthe parts thereof shown in these figures correspond identically to those of FIGS. .1 to ,6 and, accordingly, are designated by like numerals. The primary differences between the F IG. 1 to 6 construction and the construction of FIGS. 7 to 10 reside in the employment of bushing inserts in the tie rod apertures of the form panels rather than the panel secured grouting cores, and the provision of a modified tie rod construction.

Referring now specifically to FIGS. 7 to 10, each bushing insert is designated therein in its entirety by the numeral 98. While two inserts are shown in FIG. 7, it should be understood that they are identical in construction. One insert is provided for each of the apertures 16 in the

panels

10 and 10a.

The insert 98, only one of which will be described in detail, is of tubular construction and defines a passage extending longitudinally therethrough. The passage 100 terminates at one end in a hexagonal socket 102 designed for the receipt of an Allen wrench. Externally, the insert is provided with screw threads 104 designed for self-threading receipt in the tie rod apertures of a form panel. At one end, these threads terminate in a flared collar 106. The collar defines a flat end surface at one end of the insert and is of generally frustoconical cross section. Through the latter provision, the collar is adapted to be drawn into the tie rod aperture of a form panel to a position wherein the flat end surface is flush with the interior surface of the panel. Such a disposition is shown in FIGS. 8 and 9. Ideally, the length of the bushing insert is substantially equal to the thickness of the form panel in which it is used.

The preferred tie rod for use with the bushing inserts 98 is shown in FIGS. 7 and 8 and designated in its entirety by the numeral 68a. This rod is similar to the aforedescribed rod 68 in that it is of the snap-tie type. The end lengths of the rod are each designated by the numeral 72a and the length intermediate the end lengths is designated by the numeral 74a. Between each of the end lengths and the intermediate length a deare hot-upset" similarly to the ends of the aforedescribed rod 68.

Grouting cores, designated 110, employed with the tie rod 68a are concentrically received on and carried by the end lengths 724. These cores are snugly received on the rod in abutting engagement with the collars 760.

Each core is comprised of generally frusto-conical end portions 112 and 114 and an intermediate cylindrical portion 116. The portions 116 and proportioned for THE FIG. 7 AND SMETHOD The method of employing the structure of FIGS. 7

and 8 for the construction of a concrete form is sequentially carried out to the following steps:

I. The

panels

10 and 10a are disposed in stacked facing relationship and apertures (16) are drilled therethrough.

2. The walers and waler brackets are secured to the respective panels.

3. The bushing inserts 98 are securely screwed into the apertures to the condition illustrated in FIG. 8.

4. The panels are disposed in opposed face-to-face relationship, as illustrated in FIG. 7, with the apertures in alignment. i

5. The rod 74a is passed through the panels from one side of one of the panels.

6. The ends of the rods are engaged by the gripping jaws on the respective waler brackets to secure the rods against axial movement relative to the panels and maintain the panels in opposed spaced relationship with the cylindrical sections 116 of the grouting cores 110 received in the bushing inserts 98.

The latter condition can be seen from FIG. 8. It should be understood that the rod 68 and the cores 110 are so proportioned that the cores are positioned as shown in FIG. 8 when the terminal end portions 80a are fully gripped by the waler brackets. Ideally, this disposes the grouting core so that the line of demarcation between the endportion 112 and the cylindrical portion 116 is substantially coincident with the flat end surface on the flared collar 106.

In use, once a concrete form is thus constructed, concrete is poured between the panels and allowed to set. After the concrete has set, the panels may be readily removed by releasing the gripping jaws of the waler brackets from the tie rods and pulling the panels from the formed concrete. After removal of the panels, the end lengths of the tie rods are snapped and removed, together with the grouting cores 110. Thus, clean grouting pockets are provided in the surfaces of the formed concrete. It should be understood that, if desired, the end lengths and grouting cores may be broken away before removal of the form panels.

The-removed panels may be readily reused by simply repeating the steps of disposing the panels in opposed face-to-face relationship with the apertures therein aligned and passing and securing the tie rods between the panels. In this operation, the tie rods and the grouting cores carried thereby are the only elements which need to be renewed. The panels, walers, waler brackets and bushing inserts are all reused, since they remain secured when the panels are removed from a previous pour of concrete.

ALTERNATIVE USE OF THE FIG. 7 TO 10 CONSTRUCTION The phantom line representation of FIG. 9 illustrates the manner in which the bushing insert 98 may be used with a conventional snap-tie tie rod. With this type of rod, the form panels are assembled around the tie rod and the feed through system is not employed. The employment of the bushing insert in this environment functions to seal and protect the edges of the tie rod opening in the form panel and provide a smooth bearing surface for the grouting core carried by the tie rod. The tie rod and grouting core in FIG. 9 are designated, respectively, by the

numerals

118 and 120.

Where a grouting pocket is not desired, the bushing insert 98 may be used in a manner similar to that shown in FIG. 9, but with a washer type tie rod. In such an environment, the washer would take the place of the grouting core 120 and be carried by the tie rod for abutting sealing engagement with the flat end surface of the collar 106.

CCNCLUSION From the foregoing description, it is believed appar ent that the present invention enables the'attainment of the objects initially set forth herein. This is believed especially evident from the characteristics of the invention which provide for the feeding of tie rods through opposed panels from a position to one side of one of the panels and for the reuse of all of the forming components, with the exception of the snap-tie rods and the elements carried thereby. The manner 'in which the reusable components remain secured to the panels at all times is particularly advantageous from a labor saving standpoint in gang form assemblies.

I claim:

1. A grouting plug core for use in combination with a form comprising: 1

A. a form panel having an interior surface against which concrete is formed and an aperture therein for the passage of a tie rod therethrough;

B. a tie rod extending through said aperture; and,

C. gripping means mounted to said panel for selective engagement with said rod to lock said panel against axial movement relative to said rod;

said core comprising: I

l. a truncated conical body having:

a. a substantially planar base surface adapted to seat against the interior surface of said panel and over the aperture therein with the body extending outwardly from said interior surface, said base surface having an area greater than the transverse cross sectional area of said aperture and said body converging uniformily from. said base surface to define a smooth conical exterior surface; and,

b. a passage extending generally axially therethrough, said passage being adapted to have said rod passedtherethrough upon seating of said surface against said panel and over the aperture therein;

2. dowel means secured against axial movement relative to said body and extending laterally from the base surface thereof, said means being receivable in the aperture of said panel 'to maintain said surface in an aligned position covering said aperture and being adapted to have said rod passed therethrough; and, Y

3. retention means adapted to secure said dowel means against axial movement relative to the panel and in received condition within the aperture therein.

2. A grouting plug core according to claim 1,

wherein:

A. said dowel means comprises a tubular section formed integrally and in substantially axial alignment with said body; and,

B. said retention means comprises a screw threaded surface formed on and externally of said tubular section for gripping engagement with the internal surface of an aperture within which said dowel means is received.

3. A grouting plug core according to claim 2, further comprising wrench engageable means operatively associated with said dowel means to provide for the turning thereof with a wrench to selectively thread said screw threaded surface into and out of gripping engagement with the internal surface of an aperture.

4. A grouting plug core for use in combination with a plywood form panel having an interior surface against which concrete is formed and a tie rod aperture extending therethrough, said core comprising:

A. a truncated conical body having:

1. a substantially planar base surface adapted to seat against the interior surface of the panel and over the aperture therein with the body extending outwardly from said interior surface, said base surface having an area greater than the transverse cross sectional area of said aperture and said body converging uniformly from said base surface to define a smooth conical surface which will form a smooth flange-free conical recess in the face of a concrete slab formed against the interior surface of the panel: and,

2. a passage extending therethrough, said passage being adapted to have the rod passed therethrough upon seating of said base surfaceagainst the panel and over the aperture therein;

B. a dowel formed integrally with said body and extending laterally from the base surface thereof, said dowel having screw threads on the external surface thereof for self-threading engagement with the aperture in the form panel to draw the base surface into seated engagement with the panel.

Claims

1. A grouting plug core for use in combination with a form comprising: A. a form panel having an interior surface against which concrete is formed and an aperture therein for the passage of a tie rod therethrough; B. a tie rod extending through said aperture; and, C. gripping means mounted to said panel for selective engagement with said rod to lock said panel against axial movement relative to said rod; said core comprising: 1. a truncated conical body having: a. a substantially planar base surface adapted to seat against the interior surface of said panel and over the aperture therein with the body extending outwardly from said iNterior surface, said base surface having an area greater than the transverse cross sectional area of said aperture and said body converging uniformily from said base surface to define a smooth conical exterior surface; and, b. a passage extending generally axially therethrough, said passage being adapted to have said rod passed therethrough upon seating of said surface against said panel and over the aperture therein; 2. dowel means secured against axial movement relative to said body and extending laterally from the base surface thereof, said means being receivable in the aperture of said panel to maintain said surface in an aligned position covering said aperture and being adapted to have said rod passed therethrough; and, 3. retention means adapted to secure said dowel means against axial movement relative to the panel and in received condition within the aperture therein.

2. A grouting plug core according to claim 1, wherein: A. said dowel means comprises a tubular section formed integrally and in substantially axial alignment with said body; and, B. said retention means comprises a screw threaded surface formed on and externally of said tubular section for gripping engagement with the internal surface of an aperture within which said dowel means is received.

2. a passage extending therethrough, said passage being adapted to have the rod passed therethrough upon seating of said base surface against the panel and over the aperture therein; B. a dowel formed integrally with said body and extending laterally from the base surface thereof, said dowel having screw threads on the external surface thereof for self-threading engagement with the aperture in the form panel to draw the base surface into seated engagement with the panel.

2. dowel means secured against axial movement relative to said body and extending laterally from the base surface thereof, said means being receivable in the aperture of said panel to maintain said surface in an aligned position covering said aperture and being adapted to have said rod passed therethrough; and,

4. A grouting plug core for use in combination with a plywood form panel having an interior surface against which concrete is formed and a tie rod aperture extending therethrough, said core comprising: A. a truncated conical body having: