US2683914A - Method of making reinforced concrete tanks - Google Patents

Description

y 1954 R. REIMBERT METHOD OF MAKING REINFORCED CONCRETE TANKS Filed Aug. 9, 1949 INVENTOR RAY/V) 0ND REM/[BERT BYW/MVMW ATTORNEYS Patented July 20, 1954 METHOD OF MAKING REINFORCED CONCRETE TANKS Raymond Reimhert, Santa Rosalia, Lower California,

Mexico, assignor to Etablissements Tangerois dExpansion Industrielle & Commerciale, a society of France Application August 9, 1949, Serial No. 109,381

Claims priority, application France August 11, 1948 1 Claim. 1

The present invention relates to structures of closed section intended to contain a fluid, this term including, in a very general manner all structures such as storing chambers, silos, tanks, vats, reservoirs, conduits, etc, which are to support, when filled, a radial outward thrust, and it is more especially, although not exclusively, concerned with large size reinforced concrete tanks intended to contain liquids.

Its chief object is to provide a structure of this kind which is better adapted to meet the requirements of practice than those used up to this time.

A preferred embodiment of my invention will be hereinafter described, with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 is a diagrammatic vertical axial section of a tank made according to my invention;

Fig. 2 is a horizontal section corresponding to Fig. 1;

Fig. 3 is a perspective view of a portion of this tank during the manufacture thereof.

The tank shown by way of example by the appended drawings is of general cylindrical shape with vertical generatrices. It might be of any other desired shape, for instance a polygonal horizontal section.

The inner wall of the tank is constituted by a plurality of vertical elements I, advantageously I adjoining one another, having each a concavity turned toward the outside.

These elements cooperate with at least one hooping part such, for instance, as an outer polygonal wall 2 circumscribed to the inner wall I, this outer wall being arranged to be subjected, when the tank is empty, to a compression stress which tends to oppose, when the tank is being filled, to the outward radial stresses exerted by the liquid on the inner wall I.

Owing to this construction, I avoid having the constitutive elements of the inner and outer walls subjected to the action of tensile stresses, which concrete parts are not adapted to support satisfactorily.

This results from the fact that elements I, which are in the state of rest when the tank is empty, undergo chiefly compression stresses when the tank is being filled, while the external wall 2, which is subjected to compression stresses when the tank is empty, is gradually relieved from these stresses when liquid accumulates in said tank.

Of course, the fatigue undergone by the external wall when the tank is full will depend upon the intensity of the preliminary compression stress imparted thereto. This preliminary stressing may, in some cases, balance only a portion of the tensile stresses resulting from the filling of the tank (in which case the whole is calculated so that the tensile stresses imposed on the concrete are below admissible limits). In other cases, the preliminary compression stressing will balance exactly the stresses produced by the filling of the tank, and it may even be higher than these stresses, so that the external wall is always subjected to compression stresses.

The preliminary stressing of the external wall is preferably obtained in the following manner:

Radial expansion of the external part 2 is ensured by filling the tank at least partly, after which said external part is finished and fixed in its final dimensions.

It will be readily understood that, according as the tank is only partly filled, wholly filled, or subjected to a pressure higher than that corresponding to complete filling thereof (for instance by providing an overload above its maximum level), the preliminary stressing that is obtained:

Either partly balances the expansion stresses exerted on the inner wall of the tank once it is filled;

Or exactly balances said stresses;

Or is superabundant.

In actual practice, the operation can be carried out very easily by first forming, for instance by molding, a concrete structure constituted by the inner wall I and portions 2 of the outer wall, as shown by Fig. 3, arranged so as to leave, between two adjacent external wall elements 2 (integral with the inner wall I), a vertical slot 212 (visible on the left hand portion of Fig. 3) across which pass the hooping metal reinforcements 2b of said external wall. Said slot is widened when the tank is temporarily filled with liquid, is then filled with concrete, as shown at 20 by the right hand side portion of Fig. 3, once the maximum expansion has been obtained. The concrete inserted in slot 2a may be of the expanding kind.

As soon as the filling concrete 20 has set, the tank may be emptied and the outer wall 2 is subjected to a. compression stressing by its reinforcements 2b which cannot return to their initial state due to the filling of slots M.

It will be seen that such a method might be used for the construction of a single wall tank. It would then suffice to provide removable inner walls capable of temporarily stopping the expansion slots during the preliminary filling of the tank, these inner walls being removed as soon as the filling concrete has set.

It should be noted that it will be of interest, in order to permit free expansion of reinforcements 2bin the concrete mass, when the external wall is being subjected to pre-stressing, to coat said reinforcements with a lubricant, for instance a bituminous paint, except at their ends,-which must be anchored over a sufficient length.

Finally, concerning the bottom of the tank, it may be constituted by a concrete floor including a main portion 3a and an annular portion 31; carried by the walls, the anchoring reinforcements carried by said annular portion 317 being left temporarily unattached before thepreliminary filling operation and being anchored in the main portion Eb only after the external wall 2 has been given its preliminary stressing.

According to another feature of the invention, based upon the fact that the standardized diameters of various tanks vary by amounts equal to one half of the practical unit of length, for instance one half of a yard, I choose, as width ao of the elements of the tank, a value equal to that is to say 1.57 yard (or a value equal to subemultiple thereof) Thus, the same elements will permit of building tanks of different dimensions ranging from 20 cubic yards to 20,000 cubic yards, with a difference of one half of a yard between the diameters of tanks of different sizes. The perimeter of the tank will always correspond to a number of elements equal to an integer.

Such a feature is particularly interesting for the construction of reinforced concrete tanks because the same timbering means will be used irrespective of the size of the tank.

Of course, the tank element might be made equal to 1r 1 yard.

The tanks according to my invention may be made of any material. other than concrete, for instance a plastic material. Furthermore, my invention is applicable to the case in which the liquid is in movement, for instance when the structure constitutes a conduit under load.

X 1 yard In a general manner, while I have, in the above description, disclosed what I deem to be practical and eflicient embodiments of my invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the accompanying claim.

What I claim is:

The method of making a concrete tank which comprises forming a preliminary structure that includes a bottom wall and an upstanding radially expansible continuous side wall of generically cylindrical shape, said side wall being constituted b a plurality of integral side by side vertical strips having a curved cross-sectional shape, each strip having a convex side facing the inside and a concave side lacing the outside, each of said strips carrying integral therewith on its outer side edges two external reinforced concrete wall portions, said external reinforced concrete wall portions extending toward each other across the concave side of the strip and being spaced apart from each other to leave a gap between them ther in and emptying said structure only a; ter said substance has set and hardened.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 772,117 Winslow Oct. 11, 1904 1,001,273 Ingraham Aug. 22, 1911 1,278,111 Cummings Sept. 10, 1918 2,091,444 Hewett Aug. 31, 1937 2,389,057 Kandall Nov. 13, 1945 2,474,660 Fitzpatrick June 28, 1949 2,477,930 Hie ert Aug. 2, 1949 2,483,175 Billner Sept. 27, 1949 2,585,446 Edwin et al Feb. 12, 1952

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