Method and an apparatus for producing fabric-reinforced lining supports or slender supporting structural units

A method of producing structural supports for use particularly in mining applications includes the use of a relatively rigid and cylindrical shell casing. The shell casing is separable along the plane parallel to its axis, has open ends and is closed about a fabric tube which is axially supported therein. The fabric tube is filled with pressurized liquid building materials such as concrete. Once filled within the casing, the pressure of the building material forces the liquid component thereof out of the tube laterally and through perforations provided in the shell casing to drain the liquid away from the building material in the tube. The casing and tube are of size such that the remaining building material, which will constitute a pillar, extends completely between the surfaces it is to separate and support. Once the liquid has been drained from the building material within the fabric tube and shell casing, the shell casing can be removed even before the remaining building material is hardened into a pillar reinforced with an outer fabric tube. The shell casing can then be reused for producing additional fabric reinforced pillars.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a method for producing lining supports or 
elongated supporting structural units from a hardening building material 
and a reinforcement. These parts can be produced on the site by overgound 
and underground construction, the building material being liquid and 
brought together with the reinforcement only at the installation site. 
Lining supports produced using the invention are particularly suitable for 
mines and tunnel construction as an independent road lining or part of a 
road lining in which the lining supports act as props or prop pillars for 
the separately supported (anchored or lined) roof or the exposed rock. 
Inventive props and prop pillars differ from each other essentially by 
their slenderness ratio, that is, the ratio of diameter to length. In so 
far as the invention also relates to the production of elongated beams for 
overground and underground construction, these beams may be masts such as 
those used as lantern poles for strong sources of light, chiefly in street 
lighting. The inventive method may also be used to produce other beams, 
for example bulkheads. 
The man field of application of the invention, however, is in drift mining, 
and in particular coal and ore mining. More precisely, the invention is 
useful for the road lining, where the inventive supports are used as a 
supporting lining in particular in a gate-end road whose roof may be 
secured by a temporary lining, for example anchored. The invention shall 
therefore be explained herein chiefly with reference to this field of 
application. 
2. Description of the Prior Art In the main field of application of the 
invention referred to above, the inventive lining supports replace the 
pillars employed in particular in pillar-and-chamber work but also in 
longwall work and used as a supporting lining, and set in single or double 
rows. In so far as these pillars have been made of wood up to now, they 
are crosswise and horizontal layers of trimmed timbers. Wooden pillars of 
this kind are flexible to a certain extent due to their compressibility, 
which is advantageous in terms of lining technology for avoiding premature 
destruction of the lining by the rock pressure. While wood is usually, 
though not always, available and can be processed well, it is generally 
expensive. Further disadvantages in terms of wooden lining technology are 
the varying strengths of the timbers cooperating in a pillar, and the lack 
of lateral stability of the pillars depending on their slenderness ratio. 
The lack of resistance of wood to moisture and fire also occasionally 
causes considerable problems. The economy of such pillars is also 
diminished by the considerable expenses for the transport and processing 
of the wood and the high labor costs underground for erecting the pillars. 
By using a hardening building material and a reinforcement, the invention 
aims at lining supports which, due to their production on site in the 
drift, are easier to transport and cheaper to erect. In addition, the prop 
pillars of the present invention do not involve any problems of lateral 
stability due to their design, and are insensitive to moisture and fire. 
Wooden pillars are the oldest known lining supports used in longwall work 
and pillar-and-chamber work, and there have already been proposals to 
replace them by pillars made of reinforced concrete. These are mainly 
concrete ties provided with reinforcing bars, which replace the trimmed 
timbers. A supporting lining consisting of such pillars involves the 
disadvantage that it is much heavier than a wooden lining, which 
considerably aggravates the transport problems and increases the labor 
costs, so that no advantages can be obtained beyond the possibility of 
replacing expensive and possibly unavailable wood by an available building 
material and eliminating the problems of fire resistance and insensitivity 
to moisture. In addition, however, the transport and erection of the 
described concrete tie pillars are complicated by the difficulty, based on 
the reinforcement, that the protruding reinforcing bars constitute a 
considerable danger of accident. On the one hand, they may cause dangerous 
injuries; on the other hand, they frequently crop up as unexpected 
obstacles. 
In order to increase the necessary inner strength of the pillars and ease 
the problems of reinforcement, another known proposal suggests building 
cylindrical pillars of prefabricated cylindrical plates of steel fiber 
concrete. These pillars follow the principle of pillars made of concrete 
ties because the plates are stacked. The production of such prefabricated 
concrete parts already makes relatively high demands on the material due 
to the required strengths. Transport is expensive due to the high weight 
and often involves considerable danger of accident due to protruding steel 
fibers. The erection of the pillars must take place without setting 
pressure, so that an individually fitting wooden wedging must be provided 
between the upper end of the pillar and its contact surface. The labor 
expended is accordingly high. Nevertheless, the pillars are not always 
successfully set perpendicular to the stratification. This leads to uneven 
loads which may destroy this kind of pillar prematurely. The invention 
aims in particular at a lining support which avoids the dangers existing 
up to now. 
Pull-out or telescoping props have also been proposed to replace wooden 
pillars. These props have telescopic parts made of relatively cheap 
material that are locked relative to one another after the prop is pulled 
out, and then filled with a hardening building material. Such a lining 
system with props or prop pillars avoids the problems of too little 
lateral stability of the pillar construction due to its consisting of one 
piece, but makes special demands on the material used as a filling; since 
the mixing water remains in the building material as it hardens, the 
production of such props must proceed relatively slowly. The expense for 
the telescopic prop part varies depending on the length and diameter of 
the prop pillar. Thus, of the main advantages of the pull-out prop system, 
namely the easier transport and low-quality material, are at least partly 
lost. Due to the lack of strength of cheap materials, the sturdy 
construction required for prop pillars is not possible. 
On the other hand, the invention differs from a complete supporting lining 
produced underground of the form which supports at least the ends and the 
roof of a road, is made of fabric tubes extending in the transverse and 
longitudinal directions of the road but is filled with hardening building 
material progressively in the longitudinal direction of the road. In this 
arrangement, the pressure of the pumpable building material is used to 
obtain the shape and contact of the lining member in question against the 
rock from the initially slack tube as it is filled with the liquid 
building material, which presupposes that the proportion of water is 
retained in the tube. The fabric tube acts only as a shaping dead mold 
which, due to its waterproofness, greatly delays the hardening of the 
building material, thereby demanding considerable labor and time and in 
practice not leading to sufficient early strengths for the lining. It is 
virtually impossible to reinforce such a lining either, whereby the tube 
itself is useless after the building material has hardened. By contrast, 
the present invention aims at the production of a quickly supporting 
lining member whose load capacity is higher than that of the building 
material pillar. 
Lining members of this kind, which develop high load capacity due to a 
composite construction, are already known in the form of the 
above-described pillar design with prefabricated reinforced concrete 
parts, but could not be produced from building materials in fabric tubes. 
However, fabric tubes filled with hardening building material are known as 
auxiliary elements in road lining which, when pumped up with the liquid 
building material, join the road lining to the surrounding rock by being 
braced between the segments of the road lining and the lagging and the 
rock. In this method the expandability of the folded fabric tube inserted 
into the support section is systematically exploited upwardly and to the 
side, the tube being provided with a corresponding oversize compared to 
the cavity in the support section, and stretched by the pumping to form an 
annular body of irregular cross-section which allows, along its length, 
for positive closure of the support section and the lagging or bumps in 
the rock with the tube. The load capacity of such a lining is ultimately 
based on the extremely expensive steel lining and therefore involves only 
a small proportion of cheaper materials. In particular, lining members 
cannot be obtained therefrom in the form of props or prop pillars for 
roads driven in the seam and longwall work. By contrast, the invention 
provides a road lining which is not based on any steel lining members but 
itself has the strength required for props and prop pillars. 
SUMMARY OF THE INVENTION 
According to the present invention, the basic method, which is suitable as 
such in particular for producing sturdy props or one-piece prop pillars, 
consists in stretching a fabric tube closed at both ends between the floor 
and lined or open roof, vertically or perpendicular to the stratification, 
and filling it with pressurized building material. The tube serves as a 
filtering medium which removes the water of the liquid building material 
to the outside and retains the drained solids of the building material in 
the form of a pillar. The tube also serves as a self-supporting lining 
reinforcement after the pillar of solids has hardened. 
The inventive method involves the surprising effect that, due to the tube 
being filled from the bottom to the top and its straightness between the 
floor and roof, with a sufficiently sturdy form of the lining support as 
can be used for many props or prop pillars, the tube already has 
sufficient stability under load in composite construction with the drained 
but not yet hardened building material. This is due to the use of the tube 
fabric as a filter and the resulting rapid draining of the building 
material in all directions out of the shaped body. The building material 
therefore hardens extremely quickly but can be continuously pumped into 
the tube despite its draining before final hardening due to its being 
enclosed in the fabric tube. Thus, increasing stability under load comes 
about from the floor toward the roof in the shaped body as it is being 
formed. There is also the surprising effect that the tube fabric, when 
made of high-strength synthetic threads as obtained in particular with 
durpolasts, not only brings about the known draining effect but can also 
be regarded as a stable reinforcement of the hardening lining support. 
This outer reinforcement arises on the self-supporting length of the 
lining support and evidently holds together the building material for long 
periods of time in spite of high vertical loads on the building material 
pillar, so that the latter develops its full strength. Even if the shear 
strength of the building material is exceeded in the building material 
pillar, which becomes apparent due to cracks in the pillar behind the 
reinforcement, the cohesion of the pillar is ensured without any loss of 
load capacity. This is due in large extent to the fact that the tangential 
threads of the tube fabric have high tying stresses and the axial threads 
are biased by stretching and transmit forces because they are not bent or 
loaded against other lining members, as are the tubes acting as auxiliary 
elements in known road lining systems. 
Lining supports produced by the new method replace not only the props used 
up to now, but also the pillars. This is most advantageous not only 
because the tubes (prefabricated in particular for the necessary average 
thickness) save space and can be transported easily, but also because 
production takes place in the drift with the aid of a building material 
pump which is fed the liquid building material from transport containers, 
if it is not mixed on the site. The building material itself can take any 
amount of mixing water and can therefore consist predominantly of solids 
which, like ashes from various sources such as electrofilter and fluid bed 
firing ashes, have low strength but develop high strengths in composite 
construction after the building material has hardened, so that they 
correspond to that of reinforced concrete. Furthermore, a reinforcement 
which may consist of reinforcing rods can be provided in the described 
production method before the building material is filled into the tube, 
thereby further increasing the strength. If a low slenderness ratio, that 
is a corresponding ratio of diameter to length, is ensured, the described 
method can also be used to produce overground construction beams on the 
site, which can be used as systematic or additional supports for ceilings 
or the like. 
In the interests of obtaining optimal slenderness in such lining supports, 
but also to obtain predetermined, and in particular straight, supports or 
beam forms as generally required for the slender supporting structural 
units described, the inventive method is ordinarily carried out in such a 
way that the fabric tube is surrounded on most of its length by a 
perforated rigid shell casing in the shape of a tube. The necessary 
draining is performed through the perforations in the shell casing, and 
the shell casing is thereafter removed from the tube before the building 
material hardens. 
In this embodiment of the inventive method, the shaping element for the 
support is the tubular shell which supports the fabric. The tubular shell 
acts with the tube, due to the shell's perforations, as a filter which 
withstands extremely high pump pressures, allowing for rapid draining in 
very short time periods and for the tubular shell to be removed almost 
immediately after the filling process. The fabric tube is not overloaded 
thereby and can thus serve as an effective outer reinforcement. The shell 
casing is reusable; although it only extends over a fraction of the free 
tube length, it can prevent radial extension and undesirable curvature of 
the tube in the longitudinal direction of the support when the building 
material is being pumped in, without impairing the axial extension of the 
fabric tube. This ensures the abutment of the support. The shrinkage of 
the building material filling due to draining also allows for axial 
movability of the tube in the shell. The described combination of shell 
and fabric tube is thus dimensionally stable in so far as it allows for 
pump pressures of up to 10 bar without any noticeable deviation from the 
predetermined shape. 
The beams or lining supports produced by the inventive method can be 
produced in the drift but also in finished part factories. Since the 
outside diameter of the tube corresponds substantially to the inside 
diameter of the closed shell, these supports are as smooth as the shell on 
the outside along most of their length. They may be provided on the inside 
with a reinforcement, for example in the form of a cylindrical or conical 
wire basket which is fixed by spacers in the stretched tube before the 
filling is added. The outer reinforcement is chemically inert if synthetic 
threads are used for the tube fabric, and is thus nearly indestructible 
even when aggressive liquids are used, as met with in particular in mining 
and tunnel construction. On the other hand, if cheaper fabrics are used, 
for example jute threads, the necessary service life can be ensured by the 
type and composition of the building material selected. On the inside, the 
inventive support consists of the hardened building material. This may 
have a hydraulic component in the form of cement or a hydraulic gypsum, 
the selection depending largely on the cements or gypsums or additives 
available on the site, or on other points of view such as economy. The 
building material may contain sand and additives, depending on 
availability and expense. Instead of gravel, crushed rock and chippings, 
one may therefore also use the above-mentioned grainy ashes, in particular 
electrofilter and fluid bed ashes, for which no sufficient use could be 
found up to now but which bring about considerable and unprecedented 
strengths when processed in the inventive method. 
The inventive method is also particularly rational, in particular when 
conducted in its preferred embodiment, because only a relatively short 
shell is then required. This is made possible by the fact that, even if 
extreme pump pressures are applied, the tube ends pressed out of one or 
both ends of the shell are neither deformed nor increased in their 
diameter to any great extent on a certain length, due to the inherent 
strength of the tube sufficing for short extension. The shell expenses can 
thus be reduced by using shorter shell lengths and by avoiding shells 
designed for any particular length, by determining the particular support 
length by the length of the tube. 
In a further preferred embodiment of the inventive method, the shell 
(having a length corresponding to an average thickness) is set up and the 
tube in the shell made to abut, while being pumped up, with its upper end 
against the roof, its lower end being supported on the floor, and braced 
by the pressure of the filling. In this embodiment of the invention, the 
shell is independent of the local thickness in which a prop pillar is to 
be set. It can therefore be reused many times, in particular if extension 
pieces are used. The indefinitely long reusability is an essential 
condition for mechanizing the lining work because the shell can therefore 
be used in different roads and can be applied, for example, on the 
extension arms of a moving device which can also bear the other components 
of the prop pillar, in the form of a greater tube length, and the building 
material as well as the aggregates necessary for filling it, such as the 
pump and connecting pipes. The inventive method allows in this embodiment 
for the prop pillar to be set right up to the rock surface due to the tube 
ends emerging from the shell during pumping. If no sufficient setting 
pressure is obtained thereby, simple wedging can be used. This replaces 
manual wedging and thus saves most of this labor. 
Further, the invention allows for the support to be set up and braced in 
pressure-flexible fashion using a pressure-flexible material in the form 
of one or more plates on at least one end of the tube. This replaces any 
wedging and allows for a degree of flexibility under pressure which can be 
selected virtually precisely by the dimensions of the plate or plates and 
the selection of their material, after the exhaustion of which the prop 
pillar is rigid until its elastic deformability is exceeded. 
In particular, the plates can be used in the inventive method for removing 
water from the tube filling if a plate material is used which reacts with 
the removed water. This allows for even faster draining, in particular at 
the ends of the tube. In plates formed out of a so-called single-component 
polyurethane foam, the foaming components, which form a prepolymer 
consisting, for example, of a polyol and a polyisocyanate, react with the 
surrounding moisture. The foam when completely hardening thus withdraws 
moisture from the building material in the tube through the tube fabric, 
and in turn the mixing water, so that the tube ends first loaded harden 
faster. 
If such plates or wooden plates are used, it is expedient to support the 
plates on the upper closed end of the tube on needles which are stuck into 
the fabric and radially penetrate the tube. The tube is then filled 
axially and under the plates fixed by the needles on the tube end. The 
needles are withdrawn and thereby removed before the building material 
hardens. The needles preferably consist of lengths of sufficiently strong 
wire. 
In another embodiment of the invention, the tube filling is left out at one 
or more places and a cavity accessible from the outside is created in the 
finished pillar. Such embodiments involve the advantage, in mining and 
tunnel construction for example, that the prop pillars can be robbed or 
destroyed. A hole can be drilled in the cavity and an explosive charge 
provided therein which upon explosion causes the prop pillar to buckle. 
The prop cavity may also be longer and is then given a hollow support with 
a larger diameter but increased strength. This increases security against 
buckling. 
It normally suffices to cut off the particular tube length required from a 
reel or a stack and tie it up at both ends, thereby creating a ball of 
fabric at each end. In order to avoid disturbances due to this 
accumulation of tube fabric, a cavity can be left according to the 
invention in the middle of one or both plate for taking up the ball of 
fabric. The ball of fabric is thus sunk below the even surface of the 
plate in question as soon as the setting pressure takes effect. This 
results in improved contact with the rock, particularly on the upper end 
of a prop pillar which has an enlarged flat surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIGS. 1 and 2 show a rigid shell casing 1 with a bipartite design, The 
shell casing 1 consists of a cylindrical sheet 2 with closely adjacent 
relatively small perforations 3. The sheet 2 is divided on the 
longitudinal center plane of the cylinder, thereby creating two half 
shells 4, 5 (FIG. 4). Divided band clamps 6 to 11 are provided at their 
adjacent ends with hinges 12 which hinge together their two halves 14, 15. 
Band clamp half 15 bears at its free end a fork 16 engaged by tongue 17 
attached to the free end of other band clamp half 14. Parts 16 and 17 have 
oblong openings 18, 19 for receiving a locking wedge 20, which can be 
driven from the top to the bottom into the openings in alignment when the 
band clamps are closed, as shown at 19 in FIG. 3. Free edges 21a, 21b of 
shells 4, 5 are thus supported on each other and braced. 
Band clamps 6 and 11 attached to the ends of shell casing 1 each bear a 
conical sheet portion 22a, 22b protruding upwardly and downwardly 
therefrom, respectively. 
The inside diameter D (cf. FIG. 3) of shell casing 1 corresponds 
substantially to the outside diameter of a fabric tube 24 which is cut off 
a roll or package to a length exceeding the length or height of shell 
casing 1. Before fabric tube 24 is tied off, a plate 26 made of a flexible 
material, for example polyurethane foam 27, in inserted into the lower end 
of the tube 24, as seen in FIG. 1. Plates 28, 29 are also inserted into 
the upper end of the tube 24 before fabric tube 24 is tied. The outer 
plate, plate 28, has a recess 30 into which ball of fabric 25 resulting 
from the tying is inserted. 
The fabric tube 24 has a filler neck 31 which is directed to the outside 
through an opening 32 in one of half shells 4, 5. In the embodiment shown, 
the filler neck 31 has a check valve 33 consisting of an invisible 
flexible disk housed in flange 34 and capable of turning inside out as 
soon as it is loaded from the outside, but lying against a supporting 
cross as soon as it is pressed outwards by a larger internal pressure. 
Conical sheet-metal rings 22a, 22b ensure that fabric 35 of tube 24 is 
considerably greater than the height of rigid shell casing 1. 
After the fabric tube 24, tied off over its plates 26 to 29, has been 
inserted into shell casing 1 and the shell casing closed and braced by 
driving in its wedges 20, liquid building material is pumped into tube 24 
through neck 31 via a connecting tube (not shown). The tube 24 thereby 
comes to lie against inside 36 of the shell casing 1 but is then prevented 
from expanding further radially. The length of tube 24 beyond the height 
of shell casing 1 causes the tube ends to emerge from conical sheet-metal 
rings 22a, 22b so that they lie against rock surfaces 37, 38 formed by the 
floor and roof of a seam in which a road is driven. As soon as the tube 
ends have achieved their contact, the increase in pump pressure causes the 
mixing water of the liquid building material to be removed to the outside 
through fabric 35 and perforations 3 in shell casing 1. At the same time 
the tube ends are braced with rock surfaces 37, 38, which leads to 
compression of plates 26 to 29. The mixing water emerging from 
perforations 3 in shell casing 1 is clear. By this arrangement, the 
contents of the tube 24 are, for the most part, completely drained. The 
resulting building material and tube combination already possesses 
sufficient stability under load before hardening of its grout consisting 
of cement or gypsum or another hardenable building material. Accordingly, 
wedges 20 can be detached and the shell casing 1 opened and removed in the 
way apparent from FIG. 4. After hardening, the tube 24 (with its fabric 
35) constitutes a reinforcement for the prop pillar made of the building 
material. Shell casing 1 can be used elsewhere in the meantime to erect 
another prop pillar of the described kind. 
Prop pillar 39, which is finished after removal of the shell casing 1 and 
hardening, has a fully cylindrical design on the length of shell casing 1 
in accordance with the embodiment shown in FIG. 5. Tube ends 40, 41 
emerging downwardly and upwardly, respectively, from shell casing 1 bulge 
radially outwardly but have only a slightly larger outside diameter than 
the center cylindrical portions of the prop pillar 39. Due to its low 
value, neck 31 remains on tube fabric 35 serving as a reinforcement, but 
may also be removed, for example to recover the check valve. 
In the embodiment of FIGS. 6 to 8, the two half shells 4, 5 are completely 
separable from each other, since the closures of the embodiment of FIGS. 
2, 3, and 4, shown at 16 to 20 (FIG. 4), are provided at both ends of band 
clamp halves 14, 15, as indicated by the arrows at 42, 43, 44 and 45 (FIG. 
8). 
In another embodiment, a prop pillar is formed without a shell casing. 
According to FIGS. 9 and 10, the fabric tube 24 is closed at both ends by 
prefabricated bottoms and above-described plates 28, 29, so that it is 
leakproof at the ends even at high pressures. Since the building material, 
with its extremely short hardening time, exerts considerable pressure on 
the tube, the tube is formed from not only the highly resistant synthetic 
threads of the described kind, but also of a reinforcement 50 which, as 
shown in FIGS. 9 and 10, has a helical shape in order to ensure a fit to 
different rock openings, and in particular seam thicknesses. An inner 
reinforcement in addition to this outer reinforcement is not shown in the 
Figures. The plates at the particular ends are connected in the embodiment 
of FIGS. 9 and 10 with rings 51, 52 which are attached to the rock via 
bolts or cramps by means of a spring lock means. In this way the tube 24 
additionally provides a relatively stable and dimensionally rigid shell 
which ensures the shape of the prop pillar shown. The fabric tube 24 is 
filled under pressure via filler neck 54. 
If prop pillars of progressive sizes are to be produced, this can be 
achieved with a variability of length which allows for a fit to different 
rock openings or seam thicknesses. The possibility shown in FIGS. 9 and 10 
involves two concentric metal rings 55 and 55a between which the tube 
fabric 35 is folded in several layers in the manner of an accordian, and 
clamped. In the case of axial tensile strains, the fabric of the tube may 
be pulled out of the magazine thus formed. The clamping effect is selected 
such that the folded fabric of the tube cannot slip out of the two rings 
clamped together under the internal pressure occurring during filling. 
A very sturdy support as used in particular as a prop pillar is shown in 
FIG. 13. For particularly difficult rock conditions, the prop pillar is 
equipped with a flexibility which is ensured in the embodiment by a plate 
29 made of hard foam 56 disposed on the roof. The thickness of the plate 
determines the flexibility. Hard polyurethane foams have a low specific 
weight so that such plates are easy to transport. 
In the embodiment of FIG. 13, a robbing means (pillar destruction means) is 
also installed in the prop pillar. This is provided by a chamber 57 left 
open in the filling into which a torpedo (explosive) is inserted before 
robbing. In this embodiment the chamber can also be designed in such a 
way, however, that hydraulic pressure applied from the outside via a 
connection 58 presses or forces the prop pillar apart. A plastic bubble 
inserted into the fabric tube before filling can be used as the shaping 
element for chamber 57. 
FIGS. 11 and 12 show an apparatus which allows for partial or full 
mechanization of the production of a prop pillar. On a moving device (not 
shown) which is mounted rotatably and sluably on a small mobile vehicle, a 
superstructure with an extension arm 59 is provided. Located thereon is a 
spatially pivoted support system consisting of two rings 60, 61 and two 
props (e.g., hydraulic actuators) 62, 63. The fabric tube 24 with its 
connecting rings 51, 52 is inserted into the support system in such a way 
that rings 51, 52 come to lie against the roof and floor when props 62, 63 
are moved out (expanded). The props 62, 63 are subjected to pressure via 
hydraulic tubes 64 from the control stand of the vehicle. After the 
relatively short hardening time, which preferably lasts only a few 
minutes, swing-out parts 65, 66 (see FIG. 12) of rings 60, 61 are opened 
up on the roof and bottom (in direction of arrows 67, 68, respectively), 
so that the supporting means can be removed from the set pillar which is 
stable after draining. The containers disposed on the vehicle for the 
building material, any additives and the mixing water, as well as the pump 
for supplying the building material to the fabric tube under pressure as 
described, are not shown. 
In the embodiment seen in FIG. 1, the plates 26, 28 and 29 are larger in 
diameter than the shell casing 1. Thus, upper plates 28 and 29 rest on 
conical sheet portion 22a before and during the tube filling process. In 
another embodiment, seen in FIGS. 14 and 15, the plates 28 and 29 are 
smaller and needle means are provided to support the plates above the 
shell casing 1. At an upper closed end 70 of fabric tube 24, the plates 28 
and 29 are supported on needles 71, 72, which are stuck into the fabric 35 
and radially penetrate the tube 24. After the liquid building material is 
deposited into the fabric tube 24, the needles 71, 72 are withdrawn 
(before the building material hardens). Preferably, the needles 71, 72 are 
formed from lengths of sufficiently strong wire. 
In another embodiment of the present invention, the shell casing 1 is 
adapted to receive one or more extension pieces and thereby permit 
longitudinal extension of the shell casing. As seen in FIG. 16, the shell 
casing 1 is formed from a plurality of casing sections 74, 75 and 76. An 
upper casing portion 74 has the conical sheet portion 22a at an upper end 
thereof, and a lower casing portion 76 has the conical sheet portion 22b 
at a lower end thereof. The casing portions 74 and 76 are adapted to 
receive one or more casing extensions section 75 therebetween. Lower 
casing portion 76 has hook means 77 at an upper lend thereof for receiving 
and engaging a lower lend of the casing extension section 75, and the 
casing extension section 75 in turn has hook means 78 at an upper end 
thereof for receiving and engaging a lower end of the upper casing portion 
75. Additional casing extension sections 75 can be inserted to form a 
shell casing 1 of desired length. 
Although the present invention has been described with reference to 
preferred embodiments, workers skilled in the art will recognize that 
changes may be made in form and detail without departing from the spirit 
and scope of the invention.