US3724060A

US3724060A - Method of form tie removal

Info

Publication number: US3724060A
Application number: US00105079A
Authority: US
Inventors: Elroy J Mc
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-01-08
Filing date: 1971-01-08
Publication date: 1973-04-03
Anticipated expiration: 1990-04-03

Abstract

A method wherein a small hole with sides parallel to a form tie is drilled into the concrete, a tool comprising a long rod with a tight-fitting sleeve is slipped over the stub of the tie and is rocked within the confines of the hole until the stub tie breaks off, and the hole is patched without feather edges.

Description

v United States Patent 1 1 1111 3,724,060

McElroy 1 Apr. 3, 1973 54 METHOD OF FORM TIE REMOVAL 1,848,590 3 1932 Willis ..29/426 [76] Inventor: Joseph A. McElroy, 34 Short St., Zfil'f Randolph, Mass- 02368 2,122,181 6/1938 Rerick Ja 8, Boyer [21] APPL 105,079 FOREIGN PATENTS OR APPLICATIONS Related Us. Application Data 6l8,966 9/1935 Germany ..29/426 [62] Division of Ser. No. 762,005, Sept. 24, 1968, aban- Primary ExaminerCharles W. Lanham doned. Assistant Examiner-D. C. Crane Attorney-Alva H. Bandy et al. [52] U.S. Cl. ..29/427, 29/426, 52/99,

52 741 [57] ABSTRACT [51] II.- Cl. ..B23p 19/00 A method wherein a small hole with sides parallel to a [58] Field of Search....29/426, 446, 452, 200 H, 23 form tie is drilled into the concrete, a tool comprising 29/240 427; 81/531, 53-2; a long rod with a tight-fitting sleeve is slipped over the 249/40, 41, 217; 52/9840), stub of the tie and is rocked within the confines of the 741; 166/55-6 hole until the stub tie breaks off, and the hole is patched without feather edges. [56] References Cited 2 Claims, 2 Drawing Figures UNITED STATES PATENTS 1,381,101 6/192! Albertson ..29/426 PATENTEDAPR 3 I975 INVENTOR JOSEPH A. MCELROY ATTORNEY METHOD OF FORM TIE REMOVAL This application is divisional of Ser. No. 762,005, filed Sept. 24, 1968, now abandoned.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION This invention relates to a method for removing stub form ties from beneath the surface of reinforced concrete. When a reinforced concrete surface is finished, the form ties protruding therefrom must be removed, and they must be removed sufficiently far below the surface so that when patched over, they will not become exposed to weathering which causes rusting of the tie and spalling of the concrete. The conventional method of doing this is to bend the protruding tie and twist it, forcing the tie to break and a precut notch beneath the surface. The resultant hole is patched with mortar. However, in many cases either the concrete has been allowed to age too long before the tie is broken or the precut notch has been incorrectly placed within the form. The result is that the tie breaks off at or near the surface. In that case the conventional method for removing the stub of the form tie for many years has been to chip away a dish-shaped hole around the tie to the desired depth, to chisel or cut off the stub, and to patch the hole. Such a patch is feather-edged due to the angle the dish hole makes with the surface of the concrete, and weathers very poorly. The poor weatherability not only detracts from the structural soundness, but it also is aesthetically unacceptable. Finally, the chipping of the dish-shaped hole is timeconsuming.

SUMMARY OF THE INVENTION This invention provides a tool and method for removing such form tie stubs by utilizing a hole that will produce a superior patch. More specifically, the invention utilizes a hole that parallels the axis of the form tie and thereby in most cases is perpendicular to the concrete surface. The process consists of the steps of coring a trench around and parallel to the tie to the desired depth, breaking up and removing the concrete core, elongating the tie within the hole to the point of breaking it off flush with the bottom of the hole, removing thebroken stub of the tie, and patching the hole by filling it with mortar. To break off the stub within such a hole by elongating it, a form tie breaker tool is used comprising a straight rod having a diameter at least one-fourth inch less. than the hole in the concrete, a tapered end, means extending from the tapered end at least as far back within the rod as the depth of the hole for elongating the tie within the hole to the point of breaking it off flush with the bottom of the hole, means for applying leverage to the elongating means, and means for gripping the rod.

Accordingly, it is an object of this invention to provide a method for removing form ties from below the surface of concrete which utilize a hole in the concrete that will provide a superior, weather-proof patch.

It is a further object to provide a process of the above character which will provide such holes quickly and with uniform shape and size.

Other objects and advantages of the invention will become apparent upon reference to the following drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective illustrating the steps of the process in sequence; and

FIG. 2 is a perspective partially in section of the tool utilized.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention is utilized in conjunction with form ties in freshly set concrete, such as the illustrated concrete slab 10. The protruding ends of the form ties have been incorrectly broken off, as occurs quite frequently, so that the ends 12 of the ties are substantially flush with the surface 14 of the slab, rather than being recessed 1% to 2 inches.

In accordance with the invention, to remove the stub of the tie which is embedded in the top two inches of the surface 14 in such a way as to leave a patch with superior weathering ability, a hollow circular auger 16 having a diamond tip 18 is drilled into the surface 14 on an axis coinciding with that of the stub form tie, to form a trench 20 leaving a concrete core 22 surrounding the stub tie. The outside diameter of the trench should be no larger than 1 inch, and can be as small as of an inch. The trench will thus be perpendicular to the surface 14 in most cases, but in the event the ties protrude through the surface other than at a angle, the trench will still be parallel to the tie and will thus depart from perpendicularity.

The next step is to expose the stub tie by removing the core 22, and this is done by breaking it up by wedging so as to leave a hole 24 with the stub tie in the middle of it.

In accordance with another aspect of the invention, to break off the stub tie flush with the bottom of the hole 24, the third step, the tool 30 is utilized, having as its main component a long straight rod 32, which may be formed from steel. To contain the stub tie and thereby elongate it in the step to be set forth below so as to force it to break in tension, a hole 34 is reamed concentric with the rod 32 so as to form a sleeve 36 with a diameter which must be no greater than 0.015 of an inch larger than the diameter of the stub tie. To accommodate a stub tie that is 2 inches long, the hole 34 is drilled so that depth. Because the hole 34 is of fixed diameter, no adjustments need be made when the tool is used, and the tool cannot slip in its containment of the stub tie, which containment is so important to the step of breaking it off. In the event the ties used have a variety of diameters, a corresponding variety of tools 30 must be used so that there is a proper sized hole 34 in sleeve 36 for each size tie.

To apply leverage to the sleeve, the non-sleeve portion of the rod 32 is 7% times as long as the sleeve portion or 15 inches. To allow the end of the sleeve 38 to rock on the bottom of the hole 24 while at the same time applying force to the stub tie at its base, the end of the sleeve is tapered or champhered. To grip the tool, a conventional handle 40 is attached to the rod 32 in a conventional manner.

The tool 30 is used in the following manner: The sleeve 36 is inserted over the stub tie so that the end 38 is flush with the bottom of the hole. The tool is then worked or rocked back and forth on a straight line, as shown in phantom in FIG. 1, from one side of the hole to the other. The tool's diameter must be at least V4 inch less than the hole, to allow the rocking action. l have discovered that this action results in an elongation of the tie due to the fact that it is restricted within the sleeve, and the elongation causes the tie to break in tension.

The last step in the process is the step of patching the hole 24 with mortar, in a conventional manner. Because the hole 24 is not sloping, there are no feather edges and it is able to withstand weathering.

While the invention has been described in connection'with preferred embodiments, it will be understood that I do not intend to limit the invention to that described. On the contrary, I intend to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the following claims.

I claim:

1. A method of removing stub form ties from reinforced concrete back a substantial distance from under the surface of the concrete, said method comprising thesteps of:

a. coring a trench within the concrete around and parallel to the form tie to the depth at which the tie is to be removed;

b. breaking up and removing the concrete core so as to expose the tie and to create a hole having sides parallel to the tie;

c. breaking of? the tie flush with the bottom of the hole by inserting over the tie a tool having a sleeve with a fixed internal diameter so that the end of the tool is flush with the bottom of the hole;

(1. working the tool from one side to the other of the hole until the tie breaks;

e. removing the broken stub tie; and thereafter f. patching by filling with mortar the hole that remains.

2. The method of removing stub form ties as defined by claim 1 wherein step a comprises the step of rotating into the concrete surface concentric with the tie a hollow circular diamond-tipped auger.

Claims

1. A method of removing stub form ties from reinforced concrete back a substantial distance from under the surface of the concrete, said method comprising the steps of: a. coring a trench within the concrete around and parallel to the form tie to the depth at which the tie is to be removed; b. breaking up and removing the concrete core so as to expose the tie and to create a hole having sides parallel to the tie; c. breaking off the tie flush with the bottom of the hole by inserting over the tie a tool having a sleeve with a fixed internal diameter so that the end of the tool is flush with the bottom of the hole; d. working the tool from one side to the other of the hole until the tie breaks; e. removing the broken stub tie; and thereafter f. patching by filling with mortar the hole that remains.

2. The method of removing stub form ties as defined by claim 1 wherein step ''''a'''' comprises the step of rotating into the concrete surface concentric with the tie a hollow circular diamond-tipped auger.