WO2010047601A1

WO2010047601A1 - Improved method and apparatus for slip forming a concrete structure with steel membrane

Info

Publication number: WO2010047601A1
Application number: PCT/NO2009/000372
Authority: WO
Inventors: Otto Skovholt
Original assignee: Beton As
Priority date: 2008-10-24
Filing date: 2009-10-26
Publication date: 2010-04-29

Abstract

Method for slip forming of an upright concrete wall (0) by means of a slip form by feeding wet concrete into a slip form (12) held in yokes (4) holding one or more slip form panels.(120) and a displacement device (8) for displacing the slip form upwards, the method comprising - feeding out in parallel membrane sections (31) from membrane rolls (32) in parallel, joining the membrane sections laterally before they run into the slip form as a continuous metal membrane (30), and feeding the metal membrane down within the slip form (12) into the wet concrete.

Description

Improved method and apparatus for slip forming a concrete structure with steel membrane

Introduction

The present invention relates to a method and an apparatus for slip forming of upright concrete walls, the concrete wall comprising at least one metal membrane, e.g. a metal membrane made of steel. The concrete wall may be a part of a ring- shaped wall, a cylindrical tank wall, or a concrete construction of other shape. The purpose of the metal membrane may be to making the concrete construction fluid-tight in order to prevent leakage of fluids, e.g. liquid gases or fluids in The purpose of the metal membrane may be to making the concrete construction fluid-tight in order to prevent leakage of fluids, e.g. liquid gases or fluids in gaseous state.

Background art

PCT-patent application PCT/NO 2001/00372 relates to a panelled ceiling slip form being fed with plastic film on the surface, the plastic film is arranged to run in between the concrete wall and the panelled ceiling slip form device in a raw tunnel in order to ease the progress of slip forming. The plastic film is set in with grease to ease the progress of slip forming. Such a panelled ceiling slip form of plastic will end up on the underside of the moulded concrete panelled-ceiling and allowed to fall back down at the rear of the tunnel panelled ceiling slip form as it progresses, and thus it functions not as a barrier.

US patent 3245648 granted in 1963 describes a process of the slip forming where a rubber layer, plastic film, or a sheet of paper is fed in preferably from a roll arranged under deck of a slide form yoke. The layer which is fed down, is allowed to run tightly along the surface between the fresh concrete which is being filled up in slip form and the slide form surface, preferably on both sides of the wall which is being formed, in such way that it creates a surface on the finished moulded wall . An advantage by arranging such a rubber layer or a plastic film on the wall is that one may keep the humidity in the moulded wall for a longer time during the hardening process, and that the discontinuities otherwise arising upon interruptions in the pouring in of concrete mass will not appear as significant. An essential feature of the rather thick rubber layer which is being fed down is that when after a moulding step, by resumption of the jacking process, the rubber will be extended in the vertical direction after having attached to the concrete wall, the rubber layer will be subject to Poissonian dimensional reduction across the rubber layer when being extended vertically, so as for releasing from the concrete wall successively from the top when the jacking is of the slide form is resumed. Thus interruptions and resumptions fo the slide forming process are allowed. Even a fixedly mounted rubber mat draped about the upper and lower edge of the slide form may achieve such a function, as shown in the simplest embodiment of the invention according to US324568 in its Fig. 1.

One purpose of the present invention is to provide a fluid- proof metal membrane in or on the concrete wall and in which the metal membrane remains a part of the concrete wall while it is being slide formed.

A second purpose of the present invention is to provide a fluid-proof metal membrane in a slip formed wall in which the metal membrane is to prevent leakage of fluids through the wall, the fluids being e.g. liquid, gas or fluids in gaseous state. A third purpose of the present invention is to provide one or more methods in order for integrating one or more fluid-proof metal membranes in a slip formed cryogenic concrete tank, in which the metal membranes separately prevent leakage of the cryogenic fluids.

A fourth purpose of the present invention is to devise a simple, efficient and feasible method to form a slip formed concrete wall with a fluid-tight metal membrane.

Problems in the background art

A substantial purpose of slip forming of tanks of concrete is to obtain a fluid-tight tank. This problem is solved in the background art by arranging vertical rails along the inner slip form in such way that the vertical metal rails are arranged along the inner surface of the tank surface formed. Such vertical rails may then be used as support for welding of the metal liner sheets to the inner wall surface of the tank. For tank with such a metal lining exposed frequently or permanently to cryogenic fluids, this may be insufficient because the internal lining will shrink and bulge inwards, and one risks delamination between the metal membrane and the enclosing concrete wall's inner face, together with fatigue fracture in the metal membrane or its fastening points to the rails .

A possible solution to this problem is shown in US patent application US 2005/0144864A1, in that first, a first inner concrete layer is slip formed, whereupon a metal membrane is applied on the outside of this first concrete layer , and subsequently a tensile reinforced outermost second concrete layer is slip formed. Thus the metal membrane ends up between the two concrete layers, of which at least one of them, preferably the outermost one (exterior) , is provided with tensile reinforcement, thus the metal membrane will be locked inside and being protected from damaging displacements. However it is found several disadvantages using the prior art method for arranging a metal membrane between the inner and outer layer of a concrete wall. Firstly, the prior art method requires two subsequent slip forming processes, which involves two working processes instead of one working process as in the present invention. Secondly, the prior art method requires, that before starting the second slip forming process, a metal membrane is held on the first slip formed tank wall and then a new single-sided slip form panel is arranged for slip forming of the second, opposite concrete layer of the tank wall in order to enclose the metal membrane between the two concrete layers . The actual assembly work for arranging the metal membrane according to the prior art method is time-consuming and it is well-known that it may be difficult both to arrange and keep such extended, vertical and unfastened metal sheets to stand stable before welding them to the vertical rails.

With regard to interruptions of the slip forming process, US patent 3245648 may in that respect solve problems related to resumption of the slip forming process after interruptions, by means of a continuous down-feeding of a sheet of rubber material, plastic film or paper between the concrete and the slip form, so as for the slip form to avoid being stuck to the concrete but rather to bear against the film layer on the concrete. However this is not a substantial problem when using an ordinary steel plate lined slip form such as in ordinary slip forming.

US patent 3245648 to some extent solves problems related to drying-out of the surface of the concrete during the hardening process in that the rubber material or plastic film being sufficiently fluid tight to retain water, by down feeding of a coating sheet over the entire height of the slip formed wall. But a rubber sheet or plastic film according to US 3245648 will not prevent methane or the most other cryogenic liquids or fluids in gaseous state from escaping from a cryogenic tank because of the mechanical characteristic of the rubber material and its sealing properties at cryogenic temperatures. GB344628 granted in 1931 describes a stepwise moved single- sided slip form for stepwise layer slip forming of a concrete layer on an existing wall, in which a fabric material of paper, canvas or linoleum is fed down between the slip form and the concrete layer being slip formed. The single- sided slip form runs vertically on a vertical supporting rail with a sheave on the top. The patent GB344628 is thus not a continuous and self-supported slip form method but is limited by the height of the vertical supporting rail.

Further more the GB-patented device lacks reinforcement, jacks and climbing rods. A fabric material as suggested in the GB- patent may not withstand the shear stress normally arising between the concrete and the slip form by the current slip form methods .

In some cases it would be desirable that a slip formed concrete tank obtains an internal metal membrane . A such metal membrane tank may be applied as internal tank for storage of cryogenic fluids.

For cryogenic tanks, an external tank may be additionally required. The external tank serves several purposes: It should retain the gas which boils off from the cryogenic liquid. It should also retain possible fluid leakages from the internal tank. Additionally it shall hold an insulation layer and support an external roof. It shall constitute a mechanical protection for the internal tank, and it shall prevent humidity from diffusing to the inner tank. In a so-called "full containment" tank the external tank is formed in concrete with a metal lining on the inwards facing surface.

A complete LNG-tank in the classification "Full containment" based on the background art method may be built up in the following manner:

An inner liquid-tight container is enveloped by an external gas-tight container. The space formed between the outer and inner wall is filled with an insulating material : a supporting insulation layer below the bottom of the inner tank, a powder formed insulation layer arranged between the tank walls, and a light layer with mineral wool as a suspended ceiling above the inner tank, hanging from the ceiling of the external tank. The method based on the background art to build such a tank may be as follows: a) The external tank wall and the inner layer of the internal tank wall are slip formed at the same time. b) From the space between the external tank wall and what is to become the internal concrete layer of the internal tank wall, a first metal membrane is arranged, covering the inner surface of the external tank wall, and a second metal membrane is arranged on the external surface of the inner concrete layer of the inner tank. c) Subsequently, an outer concrete layer (with tensile reinforcement) is slip formed against the second metal membrane which is installed on the external surface of the inner concrete layer of the internal concrete tank being formed. The first metal membrane which is arranged on the inner surface of the external concrete wall usually does not need any concrete overcoverage . In this manner, an internal tank with the second metal membrane integrated within the tank wall of concrete is formed, and an external tank of concrete is lined on the inner face with the first metal membrane. An disadvantage of the method according to the background art is, during slip forming of so-called "full containment" tanks, temporary gates are required through the tank wall in order to transport in materials for erecting a scaffolding and for lining with metal membrane after a first slip forming operation, and for transporting equipment out from the tank after slip the forming operation. Such gates must subsequently be closed and made fluid-tight and the double walls of the tank by so doing become discontinuous and such a discontinuity may constitute a point of undesired leakage.

Short summary of the invention

A solution to problems which may arise by using the method of the background art, is a method of slip forming of a concrete wall by means of at least one slip form and a jack for displacing the slip form, wherein the new and inventive step is a metal membrane arranged to run down within the slip form within or along a surface of the concrete wall being formed.

Advantages of the invention

-A first advantage of the method according to the invention is that the metal membrane is arranged in the same operation as the slip forming process. Thus the time for conducting the slip forming process is substantially shortened.

-A second advantage of the method according to the invention is that one may achieve integration of a relatively thin, fluid-tight metal membrane with a relative thick, structurally bearing concrete wall in one and the same operation, and thus combining the properties of the metal membrane being fluid- tight, but with relatively difficultly workable structure on the construction site, with an easy workable and strong, structurally supporting concrete structure which is otherwise insufficient with regard to fluid-tightness.

-A third advantage by an embodiment of the method, if one lets a metal membrane run down against a panel of the slip form, is that the friction due to the movement of the slip form panels relative to the wall being formed, will occur between the slip form panel and the metal membrane, and thus avoid shear stress in the fresh concrete and the surface of the concrete wall. In this way the formation of internal cracks and form friction induced cracks on the surface is eliminated.

-A fourth advantage according to an embodiment of the invention is, that by slip forming of so called "full containment" tanks, no temporary gates in the tank are required in order to transport in materials for scaffold engineering and lining with metal sheets after a first slip forming operation, nor are any gates required for transporting equipment out from the tank after the slip forming operation. The slip form may be disassembled and removed over the top of the cylindrical tank wall when the slip forming process is completed.

-A fifth advantage of the method according to the invention is that one may slip form the upright concrete walls of so called "full containment" cryogenic tank in one and the same operation instead of the more time-consuming sequential operation being used in the background art.

-A sixth advantage of the invention, if one slip- forms in a metal membrane between the inner and outer concrete masses, is that one may obtain an adhesive fixation between the surface of the entire metal membrane and the adjacent concrete masses because the surface of metal membrane is submerged in the wet poured concrete mass, i.e. the concrete mass rises up and covers over the static metal surface.

-A seventh advantage of invention, if a surface membrane of metal is led into the slip form, is that the humidity in the fresh concrete may be kept considerably longer than otherwise ordinarily non-covered concrete surface walls, thus one may achieve a better hardening of the concrete, and one may avoid possible alternative actions in order to achieve good hardening .

Short figure captions

The invention is illustrated in the enclosed figures, where

Fig. 1 is a perspective view of the background art for slip forming a wall by means of a double-sided slip form;

Fig. 2 is a perspective vies of an embodiment of the invention with a double-sided set of mutually facing slip form panels held by a transverse yoke with vertical frame parts and a transverse horizontal connection between the upper parts of the vertical frame parts, and with suspended rolls of metal membrane sections which are arranged on the yoke, where the metal membrane sections are rolled out for running down along and near each of their slip form panel in such a way that it forms a metal membrane on the surface of the so produced wall, in this case on both lateral surfaces;

Fig. 3 corresponds to fig. 2 additionally showing a number of yokes along the slip form, each with their suspended rolls of metal membrane sections, in a way that they form a continuous metal membrane along both sides of the slip formed concrete wall; Fig. 4 is a cross-section of an arrangement with a slip form according to the invention with a wall being slip formed and the slip form panels and the arrangement according to the invention for keeping and feeding in one or more metal membranes between the slip form panels, here in such way that metal membranes are arranged on both surfaces of the wall under slip forming;

Fig. 5 is a side elevation view of a slip form and one single yoke drawn in accordance with Fig. 3, showing rolls with metal membrane sections for being fed out for forming a metal membrane on a concrete wall according to the invention;

Fig. 6 is a side elevation view corresponding to Fig. 5 and in accordance with Fig. 4, showing a series of yokes arranged to hold the slip form with its slip form panels, and with rolls with metal membrane sections arranged on their respective yokes. One may see the metal membrane sections arranged vertically along the slip formed wall. One may also see the rolls and their suspension arms on the vertical parts of the yokes. The illustrated layout may be a complete finished straight wall or a part of a wall, the wall being straight or curved;

Fig. 7a is a plan view of a ring-shaped complete slip form device for slip forming of a vertical cylindrical concrete tank with equipment for a metal membrane that is fed down along the radially external and the radially internal surface of the tank wall. It is also shown a detailed section with some of yokes and their suspensions for rolls of wound-up membrane sections to be rolled out; Fig. 7b is a plan view of a ring-shaped complete slip form device for slip forming of a concrete tank with a metal membrane being fed down within the concrete between the external and the internal surfaces of the tank wall under formation. It is also shown a detailed section of the slip form device which shows some of the yokes with their roll suspensions with their membrane sections being rolled out from the rolls. Additionally is shown a vertical cross-section of slip form devices and the yoke, and where metal membrane according to the invention runs down within the concrete wall . The reinforcement may thus be fed down in the concrete opposite to the lateral half portion of the wall relative to where the metal membrane runs down within the concrete;

Fig. 7c is an isometric view of the slip form device arrangement from Fig. 7a, wherein the actual slip form panels are not shown in order to clarify the illustration of the vertical lateral edges of the metal membrane sections. The metal membrane sections may be overlapping, be welded edge to edge or have a little gap in between, in which case they should be joined by vertical fastening rails or strips being explained below.

Fig. 8 illustrates horizontal sections of different embodiments of such vertical joints between the metal membrane sections' lateral edges, such as overlapping, folded or notched, welded edge to edge, or arranged with a small gap and joined via a vertical anchor rail. It is also shown an example of a backing rail which may run along with the membrane sections or may be arranged suspended from the yoke or the slip form device as a backing support during the joining, e.g. during a welding operation for joining adjacent membrane sections. Fig. 9 shows examples of shapes of metal membrane sections for forming of a cylindrical tank and a convex tank according to the invention. It is also shown a series of vertically- separated sheets arranged to be joined together, upper edge against lower edge, successively as the are fed down as the slip form process runs, however such an arrangement may involve several working operations which may be cumbersome.

Fig. 10a shows a method for slip forming two walls of a "Full containment" -concrete tank according to a preferred embodiment of the invention: an inner part of an internal tank with a membrane on the outer face, and an exterior tank with a membrane on its inward facing surface. A cover plate is also illustrated which protects the membrane rolls and the membrane sections against dust, concrete spills and water in such a way that the surface does not get polluted before welding. It is only indicated by the dashed lines, a subsequent single-sided slip form panel for forming an additional, outer concrete layer of the internal tank, with the outward facing metal membrane constituting an inner form, such as may be conducted by connecting the later slip form panel to the remainder of the slip form arrangement, but being suspended in a lower position.

Fig. 10b shows a second method for slip forming of a "Full containment "-concrete wall according to a preferred embodiment of the invention: an inner part of the interior tank with a membrane between the inner and the outer surfaces, and an exterior tank with a membrane on its inward facing surface; Please notice that since the thickness of walls in a such full containment cryogenic tank is generally between 50-60 cm, and the distance between the inner wall being about 150 cm, the distance between the concrete walls in this illustration is somewhat too small . Fig. 11 is a cross-section of an arrangement of a slip form with its slip form panels and their yoke, and with a horizontally supporting backing rail arranged from the slip form yoke, in which the supporting rail may be used as holding-on tool during formation of the vertical joint e.g. by means of a laser welding device for welding the adjoining lateral edges of the metal membrane sections. It is also shown a cover plate arranged to protect the roll sections and the membrane sections during the down feeding and weld-joining process;

Fig. 12 illustrates a slip form according to the invention equipped with a second embodiment of a cover plate arranged to protect the roll sections and the membrane sections during the down feeding and welding process. The cover plate may constitute part of a working deck.

Fig. 13 is an isometric view of a slip form device according to the invention with a such cover plate being partly in section view, during the down feeding process of the membrane sections from the membrane rollers which are arranged along the slip form.

Fig. 14 is a section of a slip form arrangement according to an preferred embodiment of the invention, with a cover plate in which the down feeding of rails is arranged to meet the joints between the adjacent membrane sections, and with the welding device arranged to weld joints or the membrane sections against the rails from a position below the cover plate under clean and protected conditions.

Fig. 15 is an isometric view of a slip form arrangement according to the invention with the covering deck plate from Fig. 14 shown partly in section, and with the rails shown extending up through the edge of the covering deck which extends a short distance in over the slip form.

Fig. 16 is an isometric view of the same embodiment of the invention as shown in Fig. 14 and Fig. 15, but seen from an perspective which better illustrates the rails being fed down through the cover plate and down along joints between membrane sections, and shows also that the rails with anchors running down into the concrete, which is illustrated as transparent for clarity.

Description of preferred embodiments of the invention

The invention is described below with reference to the attached drawing figures.

Fig . 1 shows an apparatus and a method according to the background art for slip forming of a concrete wall (0) by means of at least one slip form device (12) and a jack (8) for displacing the slip form device (12) . The slip form device

(12) is arranged on at least one yoke frame assembly (4) spanning across the concrete wall (0) wherein the yoke frame assembly (4) holds the jack (8) which climbs on a climbing rod

(7) . A mutually facing double-sided slip form (12) with slip form panels (120) is used, but a single-sided slip form (12) with one slip form panel (120) may be used if there is an existing wall or background such as a rock face to conduct the slip form process against. A working deck is arranged on either sides of the double-sided slip form (12) on the yoke frame assembly (4) .

Fig. 2 shows an embodiment of the invention and illustrates a method for slip forming of a concrete wall (0) by means of at least one slip form device (12) and a jack (8) for displacing of the slip form panel (12) as shown in Fig. 1, with a metal membrane (30) arranged to run down within the slip form (12) within the concrete or along a surface of the concrete wall (0) under formation.

A slip forming method according to the invention may be used on land to slip form a cylindrical or otherwise formed tank, a generally upright standing wall, a ring shaped wall, a multi- sided ring shaped wall, or other self-supported construction which comprises concrete. The invention may also be used for erecting a liquid tank or other fluid-tight construction at sea .

In a preferred embodiment of the invention the apparatus comprises a feeding device (20) arranged to feed metal membrane (30) evenly, at the same rate as the slip form device (12) is jacked up. The feeding device (20) may be active and motorized, or in an preferred embodiment being passive in such way that when first a lower part of metal membrane (30) is fastened in the deeper parts of the concrete construction and between the slip form panels, then the membrane (30) may be pulled out from its membrane roll (32) supported in bearings at the yokes and guided down into the concrete while the slip form panels are jacked up.

According to a preferred embodiment of the method according to the invention the slip form device (12) is arranged on and comprises at least one yoke frame assembly (4) spanning across over the concrete wall (0) , wherein the yoke frame assembly (4) holds the jack (8) climbing on the climbing rod (7) . In a preferred embodiment for forming a free-standing wall comprises the method according to the invention that a double- sided mutually facing slip form (12) with facing slip form panels(120), as shown in Fig. 2, 3, and 4 is used. It is preferred, and known by persons skilled in the art, to arrange reinforcement (2) between the slip form panels (12) , where the reinforcement runs down and ends up within the concrete wall (0) as it is formed by filling of wet concrete. Non-tensional standing reinforcement is arranged generally parallel with the climbing rods, and tensile reinforcement is arranged at least in a direction orthogonal to the standing, non-tensional reinforcement. Also other types of reinforcement may be arranged in the slip forming process according to the invention. A supporting apparatus for the vertical reinforcement rods may be arranged in such way that they stand in their correct position as the slip form panels and the concrete progresses upwards and cover the reinforcement during the slip form process.

According to an preferred embodiment of the method according to the invention runs the metal membrane (30) down over a guide roller (90) (please see Fig. 14) arranged along and close to the slip form panels (120) so as for the metal membrane to form a surface on the concrete wall (0) . In this way one may, if desired, form an outer surface or an inner surface, with permanent adhesion to the so obtained slip formed wall .

In an embodiment in which the metal membrane is arranged to run down between the concrete mass and the slip form in such a way that it forms an exterior surface on the slip formed concrete wall, may the metal membrane be arranged in such a way that the two mutually facing sides of the metal membrane may have different properties. The side facing the slide form panel (120) of the slip form (12) and which is exposed to friction may be made smooth and covered with a frictional reducing agent, such as polytetrafluoroethylene "Teflon" (R) or similar material, and the opposite side of the metal membrane may be arranged to bind to the concrete mass after being settled and hardened e.g. by being rough, grooved or arranged with a netting structure, or provided with small anchors arranged on the surface of the metal membrane which will face the concrete.

According to a second preferred embodiment of the method according to the invention the metal membrane (30) runs down into the slip form (12) and at the same time having a distance from the slip form panel (120) so as for the metal membrane to form an internal membrane within the concrete wall (0) formed. In this case the concrete must be filled between the slip form panels on both sides of the metal membrane because the membrane is essentially tight.

A difference of level between the fresh liquid concrete masses on both sides of the metal membrane may result in undesired bulging of the metal membrane because of the hydrostatic pressure in the concrete mass. This may be controlled by means of a guide roller (90) arranged at a lateral distance from the slip form panel (120) or other guiding devices running down towards the still wet concrete.

An alternative to slip form a metal membrane (30) into the concrete wall (0) , by allowing it to run down with a distance from the slip form panels (120) , according to the invention in such a way that it ends up within in the formed concrete wall is as followed:

A first concrete tank shell layer is slip formed according to the method in accordance with the invention by feeding down the metal membrane (30) along at least one of the slip form panels (120) . In this way the first concrete tank layer with a metal membrane (30) on the associated surface is formed, and the metal membrane (30) in this manner constitutes a part of the first concrete tank layer without requiring major delays or difficulties concerning installation of the metal membrane. Then a second concrete tank layer may be slip formed against the metal membrane (30) with a single sided slip form (12 ') on the opposite side. In this way one achieves a concrete tank which is provided with a permanent metal membrane that is fluid-tight between those two concrete layers.

In the embodiment where the metal membrane is arranged to run down into the concrete mass, the metal membrane may be arranged in such way that the two opposite sides may have similar characteristics. Both faces of the metal membrane may be arranged to bind to the concrete mass when it settles and hardens, e.g. by the metal membrane being rough, grooved or arranged with a netting structure, or provided with small anchors arranged to reinforce the fixation to the concrete.

As shown in Fig. 2 ,3 ,5 and 6 the metal membrane (30) may according to a preferred embodiment of the invention may be subdivided into two or more membrane sections (31) . In a preferred embodiment of the invention the membrane sections extend parallel or tangential with the axis of progress of the slip form, mainly parallel with the climbing rods.

The metal membrane may in an embodiment be very thin: between 2 mm and 0.5 mm, preferably between 1 and 0.8 mm. One may use even thinner metal membrane thicknesses, e. g. 0.05 mm, a feature which requires an extremely ductile and flexible metallic quality. The membrane sections (31) may be arranged to be fed out from each of their membrane roll (32) . Arranging the membrane on a membrane roll gives the advantage of storing an very long length of the metal membrane section may be arranged on the supports arranged on the yoke frame assembly without occupying much space on the deck area or below the yoke. To assure overlapping or that the rolls become arranged adjacent with the plate section edges end on end one may, in a preferred embodiment of the method according to the invention, arrange the rolls in alternating in a first and a second elevation (or a first and second row) as shown in Fig. 2, 3, 5 and 6 or in first and second lateral distances from the slip form panels, as illustrated in Fig. 12, 13, 14, and 15.

An alternative to roll up the metal membrane sections is that the membrane sections (31) in the progress direction of the slip forming process are subdivided into sheets (39a, 39b, 39c, ...), please see Fig. 9, which are joined together in vertical sequence as they run down into the slip form (12) . However the joining of vertically following sheets by welding will result in a substantially more laborious welding task, which may be disadvantageous and may further result in an increased risk of polluting the edges to be welded.

According to a preferred embodiment of the invention is each membrane roll (32) arranged on a reel core (33) on a shaft (34) held in a reel core bearing (36) on the yoke frame assembly (4), please see Figs. 2 and Fig. 4, and also Figs. 5 and 6, and further Figs. 10 to 15. The reel core bearing (36) may be arranged mainly on a horizontal arm (37) which extends from a generally vertical beam (38v) which constitutes a part of the yoke frame assembly (4) .

In order to obtain a tank or a wall with fluid-tight membrane according to the method of the invention two and two parallel running laterally adjoining membrane sections (31) must be joined generally laterally along their edges while running down into the slip form (12) . This may be carried out by e.g. welding, soldering, gluing, tightening mass and so on, or simply by the overlapping under pressure from the hydrostatical concrete pressure, or by folding.

An alternative to weld together surface arranged running steel membrane sections above the slip form is to weld together membrane sections while they run out below the lower edge of the slip form panels.

According to a preferred embodiment of the method according to the invention, a vertical rail (35) may be arranged at the joint between two adjoining membrane sections. This is illustrated in Figs. 14, 15 and 16. In this way the vertical rail (35) may be used as a dolly block during joining between pairs of membrane sections (31, 31) in order to form the continuous membrane (30) , and constitutes a mechanical dolly as a counter force or welding backing or a foundation for welding the steel membrane by means of a welding apparatus (86) . The rail (35) may be joined to the two membrane sections and be continuously fed down into the concrete together with the membrane. A similar rail may be arranged static relative to the slip form and used merely as support for the joining, e.g. a such a static dolly may be useful at gluing, welding, backing for laser welding, or constituting Earth grounding during electric welding. In a preferred embodiment of invention may the rail (35) being fed down together with the membrane sections (31) and become deeply anchored within the concrete at the time it is set and hardened. As an alternative to welding the membrane sections (31) to the rail (35) , rivets may be shot through the metal membrane sections for joining them.

Cover plate During the process of slip forming much wet concrete spill may occur, both on the working deck and on the slip form panels, and the working area is usually directly exposed to rainfall . A not insignificant problem by joining the metal membrane sections (31) is that they should be clean whether they are going to be welded, glued or otherwise joined in order to form a fluid-tight membrane (30) . According to a preferred embodiment of the invention the slip form comprises essentially a water- and dust tight deck plate (80) arranged to cover and protect at least the portions of the metal rolls

(32) and membrane sections (31) that shall form the joint between two adjacent membrane sections (31) , at least before the membrane sections (31) run down into the slip form (12) , please see Figs. 12, 13, 14, 15 and 16. Such cover plates (80) are illustrated in Fig. 10a and in Fig. 11. The cover plate

(80) is in a preferred embodiment arranged as an ordinary, preferably continuous working deck, but being water- and dust- tight with regard to covering the desired parts of the slip form arrangement which must be kept clean. The tight cover plate (80) may comprise a horizontal cover plate (81) having a horizontal extension from inside of an upper edge of the slip form (12) and extending out at least past the membrane rolls

(32) with the membrane sections (31) in such way that these are completely covered, and a vertically covering plate (82) having an upper edge tightly fitting and connected with the horizontal deck plate (81) along its inner edge over the slip form (12) , the vertical plate extending down to at least near to the upper edge of the slip form panel (120) . This is best illustrated in the cross- section shown in Fig. 12. In a preferred embodiment of the invention a down feeding opening (85) is arranged in the deck plate (81) near the transition between the horizontal and the vertical deck plate

(81, 82) , please see Fig 14, 15 and 16, where the down feeding opening (85) is arranged to feeding down of such vertical rails (35) as being mentioned above, at the joint between two adjoining membrane sections (31) . The rails are integrated into the wall.

In a preferred embodiment of the invention the joining arrangement, preferably a welding apparatus (86) , is arranged below the deck plate (80) where it completes the joining at the joint between the adjacent membrane sections (31) while they are fed down. Such joints are shown as seam welds in Fig.8 as an example for separately welded against the rail (35) , laser welded edge to edge with the rail (35) as a welding backing, as a welded overlap edge on surface, surface against the edge, and as a electrically welded overlap with the electric weld arranged between the overlapping portions of the membrane sections (31) .

It may be desirable to guide down the rail (35) standing upright in a stable position. In an embodiment of the invention the down feeding opening (85) comprises a vertical running gap (87) in the vertical cover plate (82) , arranged to guide the vertical rails (35) down in such a way that they become in line with and integrated in the surface of the concrete wall being formed, and in which the rail at the same time forms a support for the joint between the adjacent membrane sections (31) .

It may also be desired that the rails (35) should be equipped with anchors which extend into the concrete wall. Such anchors (88), shown in Fig. 14, 15 and 16 may be allowed to pass through a vertical running slit (87) which allows the passage of the anchors (88) which extend from the side of rail (35) which face towards and ends up into the concrete. It is a risk that down feeding running opening (85) forms a passage for dust, concrete spill and water down through the cover plate (80) in such a way that the joint area gets polluted, representing a threat to the quality of the joints. In a preferred embodiment of the invention therefore a vertically oriented protective cap (89) which extends upwards away from and which envelops the down feeding opening (85) , arranged to prevent fouling or wetting of the rail (35) in order to keep the rail clean before the welding or gluing or other joining of the membrane sections (31) . The protection cap may be arranged with an upper reception section in which a new section to the vertical section (35) is inserted and welded or in other way attached to the top of the existing rail, whereby the reception section is closed. This contributes to keeping the rail clean before the welding or gluing or other joining of the membrane sections (31) until the entire assembly runs down into the wet concrete.

In an embodiment of the invention the membrane is shaped to run into a plan wall. This may be carry out simply by arranging the membrane on a cylindrical membrane roll and letting it run straight out downwards into the slip form. In another embodiment of the invention the membrane is shaped to run into a curved wall either single curved or double curved. It may be done by having a cylindrical or a barrel -shaped roll (31) and (32) , as shown in Fig. 9.

Cryogenic tanks

The metal membrane in a tank according to the invention is essentially fluid-tight, for use of the concrete wall to a storage tank for fluids, e.g. methane in liquid or gaseous state. This is essential for keeping the gas in the cryogenic tank. By utilisation of the method according to the invention one may let the membrane run into a curved slip form which produces a corresponding curved wall, such as in a cylindrical tank. This is illustrated in Figs. 7a, 7b, and 7c. Other shapes may be elliptical and may even include parabolic wall, and double curved wall-tanks with varying diameter or inclination of the wall, spherical tanks or other volume shapes with technically or architecturally determined form.

A cryogenic tank of a "Full containment" classification, with an reinforced inner tank with metal membrane within the concrete wall, and with a reinforced outer tank with metal membrane on the inner surface, may be formed as follows according to an embodiment to the method of the invention, please see Fig. 10a:

A mutually facing set of slip form panels for e.g. a cylindrical outer tank and mutually facing slip form panels for a corresponding cylindrical, concentric inner concrete wall of an inner tank is arranged, both according to the invention being arranged to let each of its metal membrane to be fed in and run down along a surface of the so slip formed concrete wall. The outer tank should be reinforced. A such first metal membrane (30) is arranged along inner surface of the exterior tank and a second such metal membrane (30) is for being added on the inner concrete portion of the inner tank being arranged on the outer plane of the inner concrete wall under formation by a slip form process according to invention, (alternatively, it may be arranged on the inner surface of a first, outer concrete portion of the inner tank) . In this stage the exterior concrete layer of the inner tank is not formed. In the next step the exterior concrete layer of the inner tank may be slip formed on the outer face of the second metal membrane (30) which now constitutes a permanent membrane of the inner tank. This is illustrated by the dashed lines showing a subsequent single-sided slip forming of an outermost concrete layer of the inner tank, with the metal membrane constituting the inner (static) form. If one has a cover plate (80) over the metal membrane rolls as being shown in Fig 10a, it may be possible to undertake an integrated slip forming of the exterior concrete layer in the reinforced state on the inner portion of the exterior wall of the tank by coupling one last slip form to the rest of the slip form panels, but this will be difficult because the vertical reinforcement line (see the vertical broken line Ri in Fig. 10a) which may be in conflict with the cover plate (80, 81) and the metal membrane. Thus by the broken lines a separate, trailing one-sided slip form is illustrated, because it requires free area for insertion of reinforcement from above when the main slip forming process is finished and the main slip form is removed. Such an outer concrete layer of the inner tank may in a preferred embodiment be slip formed with tensile (horizontal) reinforcement and non-tensile (standing) reinforcement.

Alternatively, an inner trailing slip form panel (120') may be used to form a concrete layer on an inward facing metal membrane arranged on the inner face of an outer concrete layer of an inner tank. The outer concrete layer may be reinforced.

The above mentioned process must apparently be carried out in to two processes, where the outer concrete layer of the inner tank must be slip formed sequentially last, but the slip form processes may be carried out generally at the same time to one partially spatial and with some staggered time rate process in the following way, so as for the subsequent slip forming by means of the single sided slip form of the reinforced concrete layer on the outside of the second metal membrane (30) on the outer surface of the inner tank occurs in that the single sided slip form panel is coupled to the sets of the slip form when the slip form device is elevated to a desired height after starting of its slip forming, and is raised parallel with this, and in this way slip forms successively the outer concrete layer of the inner tank a desired distance behind the inner concrete layer which is being slip formed. The outer concrete layer of the inner tank may be slip formed to the top after the inner concrete layer and the outer wall have completed being filled by concrete when their desired heights are achieved.

The insulation material is applied between the finished slip formed inner concrete tank and the outer concrete tank. The insulation is also applied within the ceiling of the tanks under formation.

In another preferred embodiment of the method according to the invention the process for slip forming a "full containment" tank be further simplified, please see Fig. 10b. A double sided slip form for the wall of an outer tank and a double sided slip form for the entire concrete wall of an inner tank comprising what shall become both the inner concrete part and the outer concrete part of the inner tank, is arranged. The outer slip form according to the invention is arranged to let a metal membrane (30) run down along the inward face of the so formed concrete wall which becomes the outer tank. The outer tank must be reinforced. A metal membrane (30) is led down between the slide form for the inner tanks wall so that it gets distances from both its inside and outside slip form panels (120) , and thus becomes a permanent internal metal membrane in the inner tank wall (0) . Form strength considerations the metal membrane (30) should be fed down radially inside relative to the tensile reinforcement of the inner tank. In this case one may advantageously arrange two sets of cover plates (80, 81, 82) above the membrane rolls in order to protect the rolls and the membrane sections, particularly the membranes' lateral adjoining edges, from undesired pollution of concrete spills, dust and water spills, before they are joined. The shown embodiment of membrane rolls arranged on the relatively inner vertical standing part of the yoke relative to each slide formed concrete wall will avoid conflict between the vertical reinforcement lines (Ro, Ri) , whether in the inner wall's outer concrete layer, nor in the outer wall as a whole.

A result of the process is that the outer concrete layer of the inner tank becomes slip formed on the outside of metal membrane (30) which now constitutes an internal part of the inner tank. Thus the double concrete tank for cryogenic fluid is slip formed in one single operation, with metal membranes arranged in their intended positions in the same operation. Thus one does not needs temporary ports in the tank in order to transport scaffolding materials and lining with sheet metal after the first slip forming operation, nor transportation of equipment out from the tank after the slip form operation; The slip form device may be dismantled and removes above the top of the cylindrical tank walls when the slip forming process is completed.

According to another embodiment of the method according to the invention for slide forming of a cryogenic tank comprising an outer tank and an inner tank, by means of an outer and an inner set of slip forms (12) with jacks (8) which displace the slip forms (12) , one may, as above, conduct the slip forming and continuous arrangement of a first metal membrane (30) fed down along the inner panel (120) of the outer slip form (12) for forming an inner metal membrane on the outer tank. This makes a metal lining on the inner surface of the protecting outer tank, as above. At the same time, one may arrange a second metal membrane (30) by feeding it down along an inner panel (120) of the inner set of slip forms (12) for forming a temporary inner surface of the inner tank. Reinforcement may preferably be arranged so as for ending up in the concrete wall part being radially outside the metal membrane (30) , and will work as tensile reinforcement. A subsequent slip forming is conducted using a single-sided slip form (12 ' ) forming a concrete layer on the second metal membrane (30) on the temporary inner surface of the inner tank. This layer needs not be fully reinforced with tensile reinforcement (horizontally) because it will be set under compression by the surrounding shrinking layers during the cooling to cryogenic conditions. This subsequent slip forming by means of the single sided slip form of a reinforced layer on the inward facing surface of the second metal membrane (30) on the temporary inner surface of the inner tank may be conducted in that the slip form is connected to the inner slip form when this has been elevated to a desired elevation after the start of the slip form process, and be elevated in parallel with this, or run in a separate slip form operation.

Claims

1. A method for slip forming of an upright concrete wall (0) by means of feeding wet concrete into a slip form (12) held in one or more yokes (4) holding one or more slip form panels

(120) and a displacement device (8) for displacing said slip form (12) characterized by

- feeding out in parallel two or more membrane sections (31) each from corresponding membrane rolls (32) , arranging said two or more membrane sections (31) extending parallel with or tangential to a progress axis of the slide forming process,

- joining said parallel running membrane sections (31) laterally before they run down into said slide form (12) thus making said metal membrane (30) generally continuous in the lateral direction,

- feeding said metal membrane (30) down within said slip form (12) to said wet concrete.

2. The method according to claim 1, feeding said metal membrane (30) down within said slip form (12) within wet concrete, forming an internal metal membrane (30) in said wall being (0) formed.

3. The method according to claim 1, feeding said metal membrane down between a surface of said wet concrete and said concrete wall (0) under formation, and said slip form panel (120) , forming a surface metal membrane (30) in said wall (30) being formed.

4. The method according to claim 1, using a feeding device (20) feeding forward said metal membrane (30) evenly, at a same rate as a displacement rate of said slip form device (12) .

5. The method according to claim 1, said one or more yoke frame assemblies (4) spanning across said concrete wall (0) being formed and holding said slip form (12) . 4. The method according to claim 3, using mutually facing slip form panels

(120),

6. The method according to claim 1, using a displacement device (8) comprising one or more jacks (8) each climbing on a climbing rod (7) .

7. The method according to claim 6, arranging said jack rod extending down into and ending up in said concrete -wall (0) being formed in the slip form (12) .

8. The method according to claim 1, further comprising

- arranging reinforcement (2) within said slip form (12), said reinforcement (2) running down into and ending up within said concrete wall (0) being formed while said slip form (12) is displaced.

9. The method according to claim 8, further arranging said reinforcement as mainly vertical reinforcement (25) and mainly horizontal reinforcement (26) .

10. The method according to claim 1, arranging each said membrane roll arranged each on a corresponding axle (34) in a roll bearing (36) connected to said yoke (4) .

11. The method according to claim 1, said metal membrane (30) running down into said slip form (12) and having a distance from one or more of said slip form panels (120) so as for said metal membrane (30) to form an internal plane within said concrete wall (0) being formed.

12. The method according to claim 1, arranging a vertical rail (35) along adjoining edges between two adjoining parallel membrane sections (31) .

13. The method according to claim 12, using said vertical rail (35) as a bracing during the joining of said two adjoining membrane sections (31) .

14. The method according to claim 12, feeding said rail (35) down together with membrane sections (31) .

15. The method according to claim 1, using a fluid-tight metallic membrane (30) .

16. The method according to claim 1, letting said membrane run into a straight wall (0) being formed.

17. The method according to claim 1, letting said membrane (30) run into a curved wall (0) being formed.

18. The method according to claim 1, arranging a generally- closed cover plate (80) covering and protecting at least the lateral portions of said membrane rolls (32) and membrane sections (31) which shall form the joints between parallel running membrane sections (31) .

19. The method according to claim 1, letting said membrane (30) be a permanent membrane (30) within or on the surface of said wall formed (0) .

20. The method of claim 1, slip forming a an internal tank concrete wall (0) and an external tank concrete wall (0) of a cryogenic tank by means of inner and outer connected slip forms (12) each having outer and inner slip form panels (120) , characterized by slip forming while using said jacks (8) and continuously feeding down said first metal membrane (30) along an inner slip form panel (120) of said outer slip form (12) to form an inner, surface membrane (30) of said external tank, and concurrently feeding a second metal membrane (30) down along a slip form panel (120) of said inner slip form (12) to temporarily form a surface membrane (30) of said internal tank, and subsequently slip forming by means of a slip form panel (12O¹) of a single-sided slip form (12') producing a concrete layer on said second metal membrane (30) thus making said second metal membrane (30) a permanent internal membrane within the concrete wall (0) of said interior tank.

21. The method of claim 1, slip forming a an internal tank concrete wall (0) and an external tank concrete wall (0) of a cryogenic tank by means of inner and outer slip forms (12) each having outer and inner slip form panels (120) , characterized by

- first, slip forming while using said jacks (8) and continuously feeding down said first metal membrane (30) along an inner slip form panel (120) of said outer slip form (12) to form an inner surface membrane (30) of said external tank, and

- secondly, slip forming wile using said jacks (8) feeding a second metal membrane (30) down along a slip form panel (120) of said inner slip form (12) to temporarily form a surface membrane (30) of said internal tank, and

- subsequently, slip forming by means of a slip form panel (120') of a single-sided slip form (12') producing a concrete layer on said second metal membrane (30) thus making said second metal membrane (30) a permanent internal membrane within the concrete wall (0) of said interior tank.

22. The method of claim 1, slip forming a an internal tank concrete wall (0) and an external tank concrete wall (0) of a cryogenic tank by means of inner and outer slip forms (12) each having outer and inner slip form panels (120) , characterized by

- first, slip forming wile using said jacks (8) feeding a second metal membrane (30) down along a slip form panel (120) of said inner slip form (12) to temporarily form a surface membrane (30) of said internal tank, and

- subsequently, slip forming by means of a slip form panel (120') of a single-sided slip form (12') producing a concrete layer on said second metal membrane (30) thus making said second metal membrane (30) a permanent internal membrane within the concrete wall (0) of said interior tank, and

- secondly, slip forming while using said jacks (8) and continuously feeding down said first metal membrane (30) along an inner slip form panel (120) of said outer slip form (12) to form an inner surface membrane (30) of said external tank,

23. The method of one of claims 20-22, feeding said second metal membrane (30) down along an outer slip form panel (120) of said inner slip form (12) thus temporarily lining said second metal membrane (30) along an outward facing surface of said inner tank concrete wall (0) being formed.

24. The method of one of claims 20-22, feeding said second metal membrane (30) down along an inner slip form panel (120) of said inner slip form (12) thus temporarily lining said second metal membrane (30) along an inward facing surface of said inner tank concrete wall (0) being formed.

25. The method of one of claims 20-22, during slip forming said inner tank concrete wall, feeding reinforcement into the wet concrete exterior to said permanent internal membrane (30) being formed.

26. The method according to one of claims 20-22, wherein the subsequent slip forming of said concrete layer on said second metal membrane (30) is conducted by allowing said single-sided slip form panel (120') of said slip form device (12') of said inner slip form (12) to trail below said slip form device (12) having been elevated to a desired height after starting its slip forming, and to be elevated in a lower position parallel with said slip form device (12) .

27. The method of claim 1, slip forming a an internal tank concrete wall (0) and an external tank concrete wall (0) of a cryogenic tank by means of inner and outer connected slip forms (12) each having outer and inner slip form panels (120) , characterized by- slip forming while using said jacks (8) and continuously feeding down said first metal membrane (30) along an inner slip form panel (120) of said outer slip form (12) to form an inner surface of said external tank, and concurrently feeding a second metal membrane (30) down between, and having distances to, an outer slip form panel (120) and an inner slip form panel (120) of said inner of slip form (12) to constitute said second metal membrane (30) becoming a permanent internal membrane (30) in the concrete wall (0) being formed.

28. A slip form device (12) for a concrete wall (0) with one or more slip form panels (120) suspended in one or more yokes

(4) and a displacement device (8) for said slip form (12) , characterized by a metal membrane (30) arranged for running down within said slip form panel (120) within or along a surface of said concrete wall (0) under formation.

29. The slip form device according to claim 28, provided with a feeding device (20) for said metal membrane (30).

30. The slip form device (12) according to claim 28, wherein said slip form panel (120) being held by at least one yoke frame assembly (4) spanning across said concrete wall (0) where said yoke frame assembly (4) holding said displacement device (8) being in form of a jack (8) climbing on a jack rod (7) .

31. The slip form device (12) according to claim 28, wherein said membrane (30) is fluid-tight and permanent.

32. The slip form device (12) according to claim 28, with reinforcement (2) arranged within said slip form device (12) comprising non-tensional reinforcement (25) and tensile reinforcement .

33. The slip form device (12) according to claim 28, wherein said metal membrane (30) is subdivided in to two or more adjacent membrane sections (31) said membrane sections (31) extending parallel or tangential to an axis of translation of slip forming process.

34. The slip form device (12) according to claim 28, wherein said membrane sections (31) are arranged for being fed out from their corresponding membrane rolls (32).

35. The slip form device (12) according to claim 34, wherein said membrane rolls (32) are arranged on a core reel (33) on a shaft (34) held in a core reel bearing (36) on the yoke frame assembly (4) .

36. The slip form device (12) according to claim 28, wherein a vertical rail (35) is placed at joint between two adjoining membrane sections (31).