US3571867A

US3571867A - Concrete cylinder capper

Info

Publication number: US3571867A
Application number: US794656*A
Authority: US
Inventors: John V Cooke
Original assignee: CECIL M SHILSTONE AND ASSOCIAT
Current assignee: CECIL M SHILSTONE AND ASSOCIAT
Priority date: 1969-01-28
Filing date: 1969-01-28
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23

Abstract

A concrete capper used in preparing a concrete test sample comprising a jiglike device for insuring the formation of a substantially planar end on the prepared sample. The jig includes a removable glass plate which permits a user to simply replace the glass plate when necessary at a small expense.

Description

United States Patent Inventor John V. Cooke New Orleans, La.

Appl. No. 794,656

Filed Jan. 28, 1969 Patented Mar. 23, 1971 Assignee Cecil M. Shilstone and Associates, Inc.

' a fractional part interest to each CONCRETE CYLINDER CAPPER 5 Claims, 5 Drawing Figs.

(1.8. CI 25/ l 18, 249/ 8 3 Int. Cl B28!) 7/00 Field of Search 249/83,

(Test Sample Digest); 25/118 (M) [56] References Cited UNITED STATES PATENTS v 1,665,445 4/1928 Conrad 249/ 83X 2,648,888 8/ l 953 Walton 249/83X Primary Examiner-J. Spencer Overholser Attorneys-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT: A concrete capper used in preparing a concrete test sample comprising a jiglike device for insuring the formation of a substantially planar end on the prepared sample. The jig includes a removable glass plate which permits a user to simply replace the glass plate when necessary at a small expense.

PATENTED MR2 3 um Fig.3

\H WWW Fig.5

John V Cooke CtM llCiilE'llh CYlLllhliiEh CAilPlElit The present invention relates to concrete cylinder cappers which are employed in preparing structural test samples of cured concrete.

Due of the methods of establishing quality and structural strength of concrete is by testing samples taken from representative batches of concrete being delivered to a project. The testing procedure consists of casting test specimens in fiber or metal molds, curing the specimens in accordance with standardized specifications, and testing the specimens in compression at a predetermined time after the initial casting. Standardized test procedure specifications are furnished by such organizations as the American Society for Testing and Materiais and the National Bureau of Standards. The results of compressive tests performed upon the cured samples establish the compressive strength of the concrete which is used to determinewhether or not the concrete utilized in a particular project complies with statutory requirements or criteria set forth by design engineers.

During conventional capping of concrete test specimens, concrete test cylinders of freshly poured concrete are molded in cylindrical iiber or steel molds. After approximately 24 hours, the hardened concrete is removed from the mold and stored in a temperatureand humidity-controlled curing room until time for testing (generally between 7 and 28 days after molding).

Frior to testing, the concrete cylinder is capped on both ends with a capping material that will develop a compressive strength greater than the anticipated strength of the concrete cylinder to be tested. The capping of the cylinder is accomplished with the aid of the preset concrete cylinder capper. Cylinder cappers, or capping plates in use today, are fabricated from refactory materials and steel which is machined to specific tolerances for planeness of the capping surfaces. These cappers are prone to pitting and scratching which destroys the usefulness of the capping plate. in the case of steel plates, the plates become pitted or warped which requires expensive machining periodically to bring the plate within the required dimensional tolerances.

The purpose of the present invention is to provide a simple jiglike concrete cylinder capper which employs an easily removable capping plate in the form of a glass plate. When the glass plate becomes scratched or cracked due to repeated and prolonged contact with abrasive concrete material, the glass plate may be easily replaced at small expense.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming-a part hereof, wherein like numerals refer to like parts throughout, and in which:

lFiG. ii is a perspective view illustrating the concrete cylinder capper of the present invention as employed to support a concrete cylinder.

PEG. 2 is a top plan view of the capper illustrated in FIG. i.

hit 3 is a longitudinal sectional view taken along a plane passing through section line 3-3 of H6. 2.

hi6. i is a longitudinal sectional view taken along a plane passing through section line M of Fit]. 2.

Fifi. 5 is a perspective view illustrating a glass plate which is employed as a capping plate when properly inserted in the concrete cylinder capper shown in HG. 1.

Referring to the drawings and more particularly FlG. l thereof, there will be seen a jiglike concrete cylinder capper generally indicated by reference numeral iii which is employed to support a conventional concrete cylinder R2 in such a manner as to form a substantially planar closure or capper at one end thereof, the capper being substantially perpendicular to the axis of the cylinder. The capper device i i includes a square base plate it having countersunk boreholes to in the four comers of the plate permitting. the base plate to be suitably mounted to a tabletop or like surface. A square glass plate i8 is utilized to cap the lower end of the concrete cylinder 12. The glass plate is characterized by a substantially uniform thickness dimension which will result in the formation of a planar cap surface at the lower end of the concrete cylinder l2. Two elongated barlike spacers 20 are disposed along opposite lateral edges of the glass plate 13 as seen in FlG. ll. The thickness dimension of the spacers must conform to the tolerance requirement of the glass plate so that the combination of the glass plate and the adjacently disposed spacers present a uniform supporting surface for a cylinder guide plate 22 which is positioned against the upper surface of glass plate id and the adjacently positioned spacers 2%.

As will be seen in H65. 1 and 2, the cylinder guide plate 22 is square in shape and has its edges in alignment with the peripheral edges formed by the adjacently disposed glass plate i8 and spacers 20. Three countersunk threaded boreholes 24 are formed along each. oppositely disposed lateral edge portion of the guide plate 22. The aforementioned threaded holes extend through the spacers 20 and the base plate 14. Thus, when suitable threaded fasteners areinserted through respective boreholes 2d, the vertically juxtaposed base plate M,

spacers 2t), and guide plate 22 are securely sealed together.

When replacement of glass 18 is required, these holddown fasteners are loosened thereby permitting the sliding of glass plate 18 from the capper 110.

As will be seen by viewing FIGS. 1-4, the guide plate 22 includes a central countersunk aperture 26 formed therein. The lowermost or inward diameter of the countersunk aperture is substantially the same as the outer diameter of cylinder 12 and the countersunk nature of the aperture permits the rapid and accurate insertion of cylinder i2'within the aperture 26.

Molten capping material usually in the form of a combination of sulfur and tire clay is placed in cavity 26 of the capper and the hardened concrete cylinder 12, to be tested, is pressed against a channel iron 28 which is vertically positioned to contact a longitudinal portion of the cylinder. The concrete cylinder is lowered into the molten capping material and allowed to remain in engagement with the glass plate id until the molten material hardens. The result is that the cylinder has a cap formed on one end. The cylinder is then removed from the capper and the other end of the cylinder is capped as just described. Again, when the molten capping material has hardened, the cylinder is removed from the capper and is now capped on both ends so that it may be tested in a compressiontesting machine for compressive strength.

in order to retain the length of cylinder 12 substantially perpendicular to the plane of glass plate ih, a channel iron 2% is vertically positioned to contact a longitudinal portion of cylinder i2. The channel iron 28 is formed so that an inwardly tapering arcuate portion Ell along the lower portion of the channel iron permits the passage of a users hand between the channel iron and the test cylinder i2 during the initial posi' tioning of the cylinder in the capper. The lowermost end of the channel iron 32 is suitably welded to the upper surface of guide plate 22.

The capped ends of the specimen permit full engagement between the specimen and the bearing blocks of a conventional compression-testing machine utilized to evaluate the strength of the specimen.

By utilizing the improved concrete cylinder capper of the present invention, rapid and inexpensive replacement of the capping plate 18, fabricated from glass, may be realized so that specimens may be continually formed which conform with the tolerance requirements set forth by the standardized specifications.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will be readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

15 claim:

A concrete cylinder-capping device for use with a concrete cylinder, the capping device comprising a base plate,

spacers positioned in mutually spaced relation on the plate, a substantially planar capping plate removably positioned between the spacers and adapted to engage one end of the concrete cylinder, a cylinder guide plate having an aperture therein, the guide plate being retained in sealing engagement with the spacers and the capping plate to form a reservoir for capping material, and cylinder support means for contacting a longitudinal portion of the cylinder thereby insuring substantial perpendicular retention of the cylinder with respect to the capping plate.

2. The device set forth in claim 1 wherein the spacers include two parallel spaced rectangular bars of uniform spacing dimension positioned in aligned underlying relationship with opposite lateral edges of the guide plate.

3. The device of claim 2 wherein the capping plate is fabricated from glass and is positioned between the spacers in a manner permitting sliding removal of the glass plate from the device and subsequent replacement thereof when desired.

4. The device set forth in claim 3 wherein the aperture in the cylinder guide plate is formed with a countersunk pen'phery tapering inwardly toward the plane of the spacers.

S. The device set forth in claim 4 wherein the cylinder support means comprises a channel member fastened at one end thereof to the cylinder guide plate, the channel member having parallel-spaced flange portions extending in parallelspaced relation to the axis of the guide plate aperture, the interior surface of the flanges providing means for contacting a longitudinal portion of the cylinder.

Claims

1. A concrete cylinder-capping device for use with a concrete cylinder, the capping device comprising a base plate, spacers positioned in mutually spaced relation on the plate, a substantially planar capping plate removably positioned between the spacers and adapted to engage one end of the concrete cylinder, a cylinder guide plate having an aperture therein, the guide plate being retained in sealing engagement with the spacers and the capping plate to form a reservoir for capping material, and cylinder support means for contacting a longitudinal portion of the cylinder thereby insuring substantial perpendicular retention of the cylinder with respect to the capping plate.

4. The device set forth in claim 3 wherein the aperture in the cylinder guide plate is formed with a countersunk periphery tapering inwardly toward the plane of the spacers.

5. The device set forth in claim 4 wherein the cylinder support means comprises a channel member fastened at one end thereof to the cylinder guide plate, the channel member having parallel-spaced flange portions extending in parallel-spaced relation to the axis of the guide plate aperture, the interior surface of the flanges providing means for contacting a longitudinal portion of the cylinder.