US1917062A

US1917062A - Concrete wall construction

Info

Publication number: US1917062A
Application number: US480932A
Authority: US
Inventors: Frank A Reinhard
Original assignee: LAWRIE L WITTER
Current assignee: LAWRIE L WITTER
Priority date: 1930-09-10
Filing date: 1930-09-10
Publication date: 1933-07-04
Anticipated expiration: 1950-07-04

Description

July 4, 1933. F-A. REINHARD 1,917,062

CONCRETE WALL CONSTRUC'I'IOM Filed Sept. 10, 195o Y I?? 11671 fr Iig. www/M l Patented July 4, 1933 UNITED STATES PATENT OFFICE- FRANK A. BENHARD, F NORTON, MASSACHUSETTS, ASSIGNOR TO LAWRIE L. WITTER,

0F BOSTON, MASSACHUSETTS Y.

CONCRETE WALL CONSTRUCTION Application filed September 10, 1930. Serial No. 480,932.

This invention relates to concrete wall construction and more particularly to a means and method for preparing a concrete wall for receiving and retaining a plaster or like finishing coat thereover. It is well known that walls of buildings constructed of concrete are plaster-receiving surface in the moulding` operation but these devices' have not been successful for various reasons, particularly since a firm bond has not been secured and the devices have been inoperative, unreliable or too expensive. The primary object of my invention is to produce a simple, inexpensive and reliable method of providing these concrete walls with undercut surfaces by which a strong and secure bond isformed with the plaster coat placed thereon, the method embodying the use of a simple and inexpensive moulding mat which may be repeatedly used in successive moulding operations.

My invention particularly embodies the use lof a resiliently compressible moulding mat of rubber o r like material .having undercut cement-recelving surfaces shapedy to form undercut plaster-receiving and retaining surfaces on the concrete wall, it being understood y that my improved moulding mat is to be used as a liner for the moulding-form wall. The matis constructed to form undercut projections extending outwardly from the wall, and 1s so resilient and compressible that after the concrete has set the mat can be readily stripped therefrom without injury. The mat is an extremely simple and cheap article of manufacture, comprising simply a plain mat with undercut'holes therethrough. Furthermore, the use ofthe mat for the purpose stated is also extremely cheap since there is little wear on the mats and they canbe used repeatedly for an indefinite period. The production of such an inexpensive method and moulding mat for the purpose stated comprises a furtherobje'ct of my invention herein.

In the accompanying drawing, I have illustrated certain specific embodiments of my invention but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims appended hereto being relied upon for that purpose. l'

Referring to the figures of the drawing:

Fig. lis a. fragmentary view showing the use of my invention in constructing a vertical poured wall.

, Fig. 2 illustrates the same after the forms have been substantially removed and the wal partly completed.

Fig. 3 is a fragmentary perspective view I of one form of my improved moulding mat.

Fig. 4 is a sectional view through a floor, the bottom or ceiling side of which is finished in accordance with my invention.

As has been heretofore stated, the exposed surfaces of concrete walls are usually finished by a coating of Irelatively inerplastic material, such as plaster, and the purpose of my invention is to provide a means and method of performing this operation with greater economy, facility and efficiency. `My invention particularly involves the use of a reslliently flexible and compressible mat, of rubber or like material, which is so shaped and used as 'to provide a plurality of undercut bonding surfaces on the concrete walls which are' tobe plastered. The mat is of such substantial and solid 4construction as to withstand the pressure exerted' thereagainst' by `the soft concrete and is so resiliently flexible and compressible as to be readily removed from the hardened Walls and particularly from the undercut surfaces formed thereon.

Thel preferred form of my improved moulding device yis shown at 10 and com- 'lprises a plain rubber mat having a plurality of frusto-conical holes 12 therein land preferably extending therethrough. The use of the mat in forming a vertical 'concrete wall4 is illustrated in Fig. 1. The purpose of the mat is to so shape the Wall surfaces that they Will lreceive and securely hold the plaster finish coating. The Wall forms 14 are therefore lined With ortions of my improved mat 10 as shown in 4ig. 1, the larger ends of the holes 12 being adjacent to the forms 14 and the mats being lightly secured to the forms by any convenient means. When the concrete 16 is poured, it runs into and fills the holes 12 as Will be understood.

After the Wall has set or hardened, the forms 14 are removed and the mats 1() may be readily stripped therefrom as shown in Fig. 2. When thus stripped, the Wall surface 18 is left with a plurality of frusti-conical projections 20 providing undercut plaster holding surfaces at their edges 22. When the finishing coat 24 of plaster is applied to this Wall, it so moulds over and about these projections and surfaces as to form a firm holding bond, clearly illustrated in Fig. 2. The mat 10 is of solid construction and of a thickness only sufiicient to provide projections 20 of the necessary length to retain the plaster coating 24, and in view of the relatively close arrangement of the holes 12 and projections 20, the mat is ordinarily relatively thin as illustrated. It should be furthermore noted that the providing of holes, and especially round holes, in the mat renders it more substantial and less liable to ining relatively long openings or recesses there- 1n. Thefmat, therefore, provides a firm and substantial lining for the forms 14 and may be applied thereto and used with a minimum expenditure of time and cost. When the Wall is hardened, the sides Will be found as true as the inner surface of the forms due to the construction of the mat lining as above described. It Will also be understood that the hnmg may be easily and readily stripped from the hardened Wall Without injury to elther the mat or Wall, since the mat does not adhere to the Wall and the only'clinging portions are the relatively small undercut surfaces of the holes 12.

While I have above described a vertical Wall, it will be obvious that my invention is by no means limited thereto. For example, in Fig. 4 is illustrated a horizontal Wall 30 providing a floor surface 32 above and a ceiling beneath. In constructing this Wall, the top surface of the horizontal floor form is lined with my improved mat and the concrete 30 poured thereonto. When the Wall is set, the form and mat are removed in the manner above described. The plaster 34 is then applied and forms a bond with the projections 36 as will be understood.

I am aware that corrugated metal is being used to provide a lbond between the concrete Wall surface and the plaster coating, the metal being moulded into the concrete Wall surface and the plaster thereafter being applied to the outer surface of the metal. This method has various and serious objections which are entirely eliminated by my improved process. The metal encloses the concrete so that it cannot properly and thoroughly dry and the metal thus retains a considerable amount of moisture at its inner surface. This moisture not only prevents proper drying and hardening of the Wall but also causes the metal to rust and thereby eventually become useless as a bonding medium. On the other hand, my improved process completely exposes the concrete wall and permits it to freely drain and dry to any degree desired l fore the plaster is applied. It is believed that the many other advantages resulting from the use of my invention AWill be clear and obvious Without further description herein.

I claim:

1. In a mould for forming a cementitious Wall with a bonding surface including underl `.cut projections for retaining plaster or the jury than would be the case With a mat havlike, a fiat supporting form, a lining thereon comprising a fiat mat having cement receiving holes therethrough and the Walls of Which are shaped to form said undercut projections, the mat being so resiliently iexible that lit may be stripped from the set Wall Without injury.

2. In a mould for forming a cementitious Wall with a bonding surface including frustoconical projections for retaining plaster or the like, a flat supporting form, a lining thereon comprising a flat mat having frusto-conical cement receiving holes therein with Walls shaped to form said projections, the mat be- Ving so resiliently flexible that it may be stripped from the set Wall without injury.

3. A mould lining comprising a resiliently lieXible mat of rubberor like resiliently flexible material having a plurality of round and undercut holes therethrough.

4. A mould lining comprising a resiliently fiexible mat of rubber or like resiliently flexiv ble material having a'plurality of frustoconical holes therein.

In testimony whereof I aiiix my signature.

FRA A. RE