US2696353A - Method of applying concrete - Google Patents

Description

Dec. 1, 1954 T. R. VESSELS 2,696 3 3- METHOD OF APPLYING CONCRETE Filed Sept. 13, 1951 2 Sheeis-Sheet 1 WIRE EE/NFOEC/NG INVEN TOR.

Wvzoaae: k. Waste-4s ATTORNEY-5 I Dec; 7, 1954 "r. R. vEssELs 2,696,353

METHOD OF APPLYING CONCRETE Filed Sept. 15, 1951 2 Sheets-Sheet 2 6;; INVENTOR.

r r firfoooez'fil iasas P W M HOIJTZIPELAYA'E BY understood that the word cement taneously United States Patent 2,696,353 lVIETHOD 0F APPLYING CONCRETE Theodore R. Vessels, Escondido, Califl, assignor to Steam- Cote Corporation, a corporation of California Application September 13, 1951, Serial No. 246,425 Claims. 01. 242-7 Second, to provide a m thod of applying concrete which utilizes steam jets as the propelling force to entrain and drive a sand-cement-water mixture at high velocity against the surface to be coated, the high temperature steam jets, not only causing improved hydration but also materially reducing curing time. It is to be as used herein means ordinary hydraulic cement.

Third, to provide a method of this class which incorporates a novel means of delivering the sand-cement mixture wherein the sand need not be in a dry state but may have a nominal moisture content without impairing the operation of the apparatus.

Fourth, to provide a method of applying concrete laminations to surfaces wherein the resulting product may be handled immediately.

Fifth, to provide a method of applying concrete laminations wherein a series of closely grouped nozzles apply the several laminations simultaneously as a pipe or mandrel is passed in front of the nozzles, and wherein the character of the laminations, immediately as applied, is such that the underlying laminations withstand such loads as may be inherent in the wrapping of steel wire reinforcing; thus reinforcing wire may be wrapped simulwith the application of the larninations.

Sixth, to provide a novel method of this class wherein a plurality of nozzles entrain and mix steam, water, sand and cement and wherein the relative amounts of liquid water suspended in the different steam jets may be varied to control the relative moisture contents of the several jets, thus enabling the coating of metal pipe under conditions in which the initial coating may have a deficiency of water to facilitate bonding or, for example, in the manufacture of concrete pipe, the initial coating may be moisture laden to facilitate removal of the mandrel over which concrete pipe is formed.

With the above and other objects in view as may appear hereinafter, reference is directed to the accompanying drawings in which:

Figure 1 is a top or plan view of my apparatus for applying concrete.

Figure 2 is a partial sectional, partial elevational view thereof, taken through 22 of Figure 1.

Figure 3 is an enlarged sectional view taken through 3-3 of Figure 1.

Figure 4 is an exaggerated sectional view of a laminated coating on steel pipe.

Figure 5 is a similar view showing the laminated coating as applied to a removable mandrel.

My apparatus for applying concrete includes a pair of side frame members 1, preferably formed of angle iron and spaced with their upright flanges in confronting relationship to define a channel. The side frames are suitably mounted on a framework (not shown). Disposed under the side frames and bridging the channel therebetween, is a conveyer belt, the upper reach of :which is in sliding contact with the underside of the 2,696,353 Patented Dec. 7, 1954 ice 2 frame members 1. The conveyer belt is mounted on rollers 3, journaled by bearings suspended under the frame members. The rearward roller is provided with a drive means 4 which may comprise a motor, gear drive and chain linkage.

Mounted above the side frames 1 is a hopper 5 having a discharge end directed between the side frames. The conveyer belt forms a closure for the lower end of the hopper. The forward side of the hopper isprovided between the side frames 1 with a vertically adjustable gate 6, which may be raised and lowered by elevator means 7, comprising a hand operated shaft, gear and rack means. The position of the lower edge of the gate 6 above the conveyer belt, determines the thickness of the layer of material which may be withdrawn from the hopper as the beltis driven. It is intended that the hopper contain a sand-cement mixture. It is not necessary that the sand be dried or otherwise especially treated to remove its normal moisture content. This is of importance for the reason that heretofore it has been necessary to maintain the sand in a dry, free flowing state.

Hinged on the shaft which carries the forward roller 3, is a bracket 8 which supports a manifold structure 9. The manifold'structure is provided with an upstanding funnel 10 which embraces the discharge end of the conveyer belt so that all material passing between the side frames is discharged into the funnel. The funnel 10 is provided with a row of outlet ports, each receiving a tube which forms an inner nozzle 11.

The inner nozzles 11 are jacketed by a steam chest 12 having depending threaded bores surrounding the inner nozzles and adapted to receive outer nozzles 13. The inner nozzles project into their corresponding outer nozzles and form therewith venturi throats 14. The steam chest 12 extends laterally from the funnel, and its side walls converge to terminate in a nipple for connection to a steam valve 15.

A water nozzle 16 projects into the steam chest near the steam valve 15 through a packing gland 17. The water nozzle is connected to a water valve 18. The water nozzle is provided with a laterally directed orifice or orifices to deliver a stream of water toward the series of inner nozzles 11. The water nozzle is rotatable so that the relative quantities of water delivered to the series of nozzles may be varied.

The'steam valve and water valve are preferably supplied through hoses so that the entire manifold structure may be moved between its normal position in which the nozzles are directed vertically downward, to an inclined position indicated by dotted lines in Figure 2' Operation of my apparatus is as follows: Steam and water are supplied to the steam chest and caused to jet downwardly through the outer nozzles 13, creating a negative pressure in the inner nozzles 11 and funnel 10. Simultaneously, the conveyer belt carries a sand-cement mixture to the funnel 10 where such mixture falls by gravity, aided by the negative pressure produced at the discharge ends of the inner nozzles. The sand-cement mixture is entrained with the steam and water as it passes through and discharges at high velocity from the outer nozzles 13. A pipe or other surface to be coated. is rotated and passed underneath the discharge ends of the nozzles 13, the direction of movement being in the common plane of these nozzles.

It should be observed that the sand-cement mixture, contained in the hopper, may be formed with sand containing a normal amount of moisture, that is, the sand may be used as it comes normally from a storage bin even though it may be damp. This is of primary importance for the reason that the cost of drying sand and maintaining it in such condition, is substantial. The use of damp sand is made possible by the unique arrangement of the conveyer belt which wipes across the underside of the storage bin to withdraw a layer of the sand-cement mixture, coupled with the arrangement wherein the sand-cement mixture is poured by gravity from the discharge end of the conveyer and caused to fall unconsolidated and freely into the funnel 10. The sand-cement mixture does not accumulate in the funnel but is immediately entrained in the downwardly flowing air created by the jetting action of the steam and thus accelerated to a high velocity by the steam jet. It will be observed that the sand-cementmixture is maintained principally in the central portion of the discharging column of the sand, cement, water and steam so that the inneriwalls. of the nozzles 1-3 are continuallywashedi by the steam and water and accumulations of cementiare avoided;

The steanris not only more economicalto produce than compressed air but has several additionalradvantages. The steam virtually eliminates: any dust; If air is .used, a large: quantity ofdustnisproduced; 'This'dust consists. largely of cement, which not only is lost but constitutes a working hazard for the. operator, requiring the use of arespirator mask- As'will be brought out? in more detail hereinafter, the 'high temperature of the steam materially improves hydration and substantially reduces curingrtime. However, my apparatus" is capable of successful 'operation by use of air. in place of steam.

Adjustmentof the water. supply, not only as to its total volume, but also as to its distribution to the several nozzles, is of. primary importance. For instance, in the applying of concrete laminations to steel pipe, a moisturedeficiency first coating is desired, whereas the:formingzof concrete pipe over collapsible mandrel, a greater moisture content is desired; Considering first the coating of steel pipe, indicated by P in Figures 2, 3 and 4, it has been foun'dthat by use of a moisture deficiency first coating, a remarkably tenacious bond is obtained.

By use of a moisture deficient steam jetted mixture of sand and cement, delivered at high velocity, a scouring action is obtained which thoroughly cleans the pipe. A large. percentage ofthe sand rebounds fromthe pipe so that the resulting coating has'a concentration offines and cement. Most of the cement remains to coat the pipe, for the sand, which rebounds, is virtually free'of' cement coating andis capable of being salvaged for reuse. This scouring action, coupled with the immediate application of" the. cement, eliminates any oxide coating which would reduce bonding between the concrete and the pipe.

In the jet application of the laminations, there-is a tendency for the water content to concentrate atthe radially inner surface; thus, the moisture content of the first coating or lamination tends to collect on the surface of'the pipeand prevents a good bond between the cement and the pipe. By providing a moisture deficient first layer, any concentration of moisture at the surface of the pipe is.immediately drawn back into the lamination. To insure complete hydration of the initial lamination, the second and third laminations are not moisture deficient but may containa slight excess for absorption into the initial lamination.

It has been found desirable to provide a moisture deficient final cost or lamination, although this is not as vital as in the case of the first coating.

In the manufacture of concrete pipe wherein the'laminations' are applied over a collapsible mandrel, indicated by M' in Figure 5, it is'desira'ble to produce'a moisture layer between the first coating and the mandrel. Consequently, instead of producing a moisture deficient first coating, adequate quantity of water is supplied to producea moisture film which will avoid any bonding and facilitate removal of the mandrel.

It should be understood thatin any case, the moisture content of the various laminations is held to a minimum so that the resulting mixture is damp rather'than wet. It has been found that with proper control of the moisture content, coupled with the action of the steam to promote hydration of initial setting, that the concrete pipe or concrete clad metal pipe may be handled immediately after being coated. By handling, it is meant that the pipe may be removed from the carriage or other means whereby it is moved past the nozzles and placed on runners or other supports, and that within a very short time, the pipe may be stacked for storage without danger of injury to the concrete.

It will be observed thtat thenozzles are closely grouped so that as the pipe or mandrel is moved past the nozzles, each lamination is exposed for only a matter of seconds before the succeeding lamination is applied. Even though this be the case, initial setting-of the concrete takes place so rapidly that it is possible to apply wire reinforcing as indicated by W in Figures2, 3, 4 and 5. For example, if four laminations A-,B, C, D are applied to the pipe, the wire reinforcing W may be introduced :between thesecond and third nozzles. so. as to be im- .tion: of moisture from one bedded between laminations B and C. It should be borne'in mind" that the wire reinforcingis applied under tension, yet there appears to be little or no crushing or displacement of the underlying laminations. Heretofore, it has been necessary to apply initial laminations, allow the laminations to cure partially and then apply the Wire reinforcing and outer laminations. This has required double handling of the pipe whereas in the present instance, both coating and reinforcing. are accomplished simultaneously.

As' will be best observed in the diagrammatical views of Figures 4 and 5, each lamination is not uniform throughout its thickness, that is, the radially inner side of each lamination contains a greater percentage of fines and cement than the outer side. This accomplishes two things, first, after the concrete has set, the innermost surface of each lamination is highly impervious to moisture; second, the roughness of the outermost surface of each lamination provides excellent bond with the confronting surface of the covering lamination. In the coating of steel pipe, this prevents migration of moisture to the pipe, and in the. forming of concrete pipe, prevents the outward. migration of water carried by the pipe.

It will be'observed that the amount of' water supplied through the water nozzle is adjusted to compensate for the initial moisture content of the sand. In addition, it will be observed that the relative volume of Water supplied to each of the nozzles .is easily regulated by turning the watersupp'ly'nozzle. In order to facilitate adjustment, and in order to avoid coating of the pipe during return movement of the carriage or other structure (not shown) which supports the pipe, the entire manifold or nozzle assembly maybe tilted to the dotted line position shown in Figure 2.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein: set forth, but my invention is of the full scope of the appended claims.

I claim:

'1. A method of applying cementitious material to a surface, characterized by: establishing a downwardlydirected jet containing liquid water suspended in steam in a substantially upright open-ended tubular structure; feeding by gravity at a predetermined rate into theupper end of said tubular structure an unconsolidated free falling mixture of. sand and hydraulic cement to be wetted and entrained by said jet; and directing the entraining jets and their contentsupon: a surface to be coated.

2. A methodof applying cementitious material to surfaces, characterized by: establishing a series of downwardly directed motive gas jets containing liquid water'in suspenslon'in a series of substantially upright open ended tubular structures; simultaneously pouring into the upper ends of said tubular structures an unconsolidated free falling mixture of sand and hydraulic cement to be wetted and entrained by said jets; and directing the entraining jets and their'contents upon surfaces to be coated.

3. A method of applying cementitious material to sur faces, characterized by: establishing a series of downwardly directed steam jets in a series of substantially upright open' ended tubular structures; introducing preselected different quantities of liquid water into said steam jets for suspension therein; simultaneously pouring into the upper ends-of said tubular structures an unconsolidated free falling mixture. of sand and hydraulic cement for entrainment in said steam jets to produce sand-cement streams having different moisture content; and directing the entraining jets and their contents upon surfaces to be coated.

4. A method of applying cementitious laminations to a. surface, characterized by: establishing a series of downwardly directed, motive gas jets containing liquid water in suspension in a series of substantially upright contiguous open-ended tubular structures; simultaneously pouring intothe upper ends of'said tubular structures an unconsolidated free falling mixture of sandandhydraulic cement to be wetted and entrained by said jets to issue from said tubular structures as streams; passingthe surface to be coated across said contiguous streams for sequential application of the contents of said. streams to form cementitious laminations; regulating the relative moisture content of said streams to produce laminations having different initial moisture content, but permitting migralamination: to the other to effect subsequent substantially uniform distribution of moisture and therefore uniform hydration of the cement.

5. A method of applying cementitious laminations to a surface, characterized by: establishing a series of downwardly directed, motive gas jets containing liquid water in suspension in a series of substantially upright contiguous open ended tubular structures; simultaneously pouring into the upper ends of said tubular structures an unconsolidated free falling mixture of sand and hydraulic cement to be wetted and entrained by said jets to issue from said tubular structures as streams; and passing the surface to be coated across the contiguous streams issuing from said tubular structures to cause the sand and hydraulic cement and water to deposit thereon in a series of laminations.

6. A method as set forth in claim wherein the liquid water content of said streams diifers whereby said laminations have different initial moisture content, but migration of water between the laminations is permitted thereby to establish subsequently a substantially uniform distribution of moisture and uniform hydration of the cement.

7. A method of applying cementitious laminations to pipe, characterized by: establishing a row of downwardly directed jets containing liquid water suspended in steam and surrounding a row of substantially upright openended tubular structures; feeding by gravity at a predetermined rate into the upper end of each tubular structure an unconsolidated free-falling mixture of sand and hydraulic cement for entrainment by said jets; and rotating a pipe with its axis substantially horizontal and passing said pipe longitudinally in a plane common to that of said jets and tubular structures, whereby said jets apply simultaneously a series of sand-cement laminations to said pipe.

8. A method of applying cementitious laminations to pipe, characterized by: establishing a row of downwardly directed jets containing liquid water suspended in steam and surrounding a row of substantially upright open-ended tubular structures; feeding by gravity at a predetermined rate into the upper end of each tubular structure an unconsolidated free-falling mixture of sand and hydraulic cement for entrainment by said jets; rotating a pipe with its axis substantially horizontal and passing said pipe longitudinally in a plane common to that of said jets and tubular structures, whereby said jets apply simultaneously a series of sand-cement laminations to said pipe; and wrapping wire reinforcing helically on said pipe starting in a region between a pair of said jets whereby said wire reinforcing is applied simultaneously with and between said laminations.

9. A method of applying cementitious material to a pipe, characterized by: establishing at least one downwardly directed jet containing liquid water suspended in steam and surrounding at least one substantially upright open-ended hollow structure; feeding by gravity at a predetermined rate into the upper end of said hollow structure an unconsolidated free-falling mixture of sand and hydraulic cement for entrainment by said jet; and rotating a pipe with its axis substantially horizontal and passing said pipe longitudinally past said jet and hollow structure, whereby said jet applies a coating of sand-cement to said pipe.

10. A method of applying cementitious material to a pipe, characterized by: establishing at least one downwardly directed jet containing liquid water suspended in steam and surrounding at least one substantially upright open-ended hollow structure; feeding by gravity at a predetermined rate into the upper end of said hollow struc ture an unconsolidated free-falling mixture of sand and hydraulic cement for entrainment by said jet; rotating a pipe with its axis substantially horizontal and passing said pipe longitudinally past said jet and hollow structure, whereby said jet applies a coating of sand-cement to said pipe; and simultaneously with the application of said sand-cement coating, wrapping wire reenforcing helically around said pipe in a region within the axial extremities of said jet, whereby said sand-cement coating underlies and overlies the wire reinforcing thereby to completely embed wire reenforcing.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 984,254 Akeley Feb. 14, 1911 1,751,343 Mack Mar. 18, 1930 1,979,656 Whitman Nov. 6, 1934 2,428,284 Krogel Sept. 30, 1947 2,495,540 Nichols et al. Jan. 24, 1950 2,543,517 Anderson Feb. 27, 1951

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