[0001] The invention relates to a method of manufacturing a box-shaped building element
in which on a first manufacturing site concrete mortar is poured and consolidated
by vibrations or shocks in the cavity of a casting mould consisting of a lower profile
gauge, a jacket, a core and an upper gauge and in which the resultant, incompletely
cured casting is removed from the core or from the jacket and is transported together
with the jacket or the core respectively to a second manufacturing site, after which
the jacket or the core respectively is removed from the still incompletely cured casting.
[0002] Such a method is known from Dutch patent specification 48,210. In this known method
the casting cannot be taken out of the casting mould until the concrete has sufficient
resistance to deformation so that a comparatively retention time in the casting mould
is required in order to avoid damage of the casting when it is taken out of the casting
mould or thereafter.
[0003] The invention has for its object to avoid damage of the casting with a short time
of residence in the casting mould. For this purpose the casting together with the
upper gauge and the lower gauge is removed from the jacket or the core respectively,
whilst at least the upper gauge is retained with respect to the casting with the aid
of positioning means.
[0004] The invention relates to and provides in addition, a building structure such as a
tunnel, sewer, culvert, composed of a sequence of joined building elements manufactured
each by the method according to the invention.
[0005] The aforesaid and further features of the invention will be described more fully
with reference to the drawing.
[0006] In the drawing show schematically
Figure 1 a display of the method in accordance with the invention,
Figure 2 an enlarged sectional view of detail II of Figure 1 in carrying out a preferred
method in accordance with the invention,
Figure 3 an enlarged sectional view of detail III of Figure 1,
Figure 4 a building structure in accordance with the invention, in which the situation
after a degree of settling in the ground is indicated by broken lines,
Figure 5 on an enlarged scale detail V of Figure 4,
Figure 6 a sectional view taken on the line VI-VI in Figure 5,
Figure 7 a variant of Figure 3,
Figures 8 and 9 each a further variant of Figure 2 and Figure 3 respectively, and
Figures 10 and 11 each a further variant of Figure 2 and Figure 3 respectively.
[0007] Figure 1 illustrates schematically the series manufacture of box-shaped building
elements 3. On a first manufacturing site 1 concrete mortar 10 is poured from a container
11 into the cavity 4 of a casting mould 5 consisting of a lower profile gauge 6, a
jacket 7, a core 8 and an upper profile gauge 9. During the uniform pouring of the
concrete mortar 10 having the humidity of earth the casting mould 5 disposed-on a
vibrating table 12 is subjected to vibrations or shocks to consolidate the concrete
mortar 10. After the mould cavity 4 is filled, the upper profile gauge 9 is pressed
against the concrete mortar 10 present in the mould cavity 4, whilst the concrete
mortar 10 is further consolidated by means of a vibrating device 13 arranged in the
upper gauge 9.
[0008] The vibrating table 12 is disposed in a cave 14 at a lower level than the factory
floor 15 on springs 16 and provided with a vibrating device 17 and is guarded by means
Of stop bolts 18 against excessive upward movements. The core 8 is detachably fastened
by means of bolts 19 to the vibrating table 12.
[0009] From a stock 20 a lower profile gauge 6 is deposited around the core 8 on the vibrating
table 12 and the jacket 7 is secured by bolts 21 to the lower gauge 6. A reinforcing
network 22 is arranged in the mould cavity 4 as well as a number of pipes 24, for
example, of synthetic resin, reserving each a passage for a pull rod 23. Each pull
rod 23 is screwed by its lower end 25 into the lower gauge 6 and has a screwthreaded
top end 26 with a square head 27 so that after the mould cavity 4 is filled and after
the upper gauge 9 is disposed thereon said upper gauge 9 can be pressed home by nuts
28. The pull rods 23 with the nuts 28 constitute positioning means for retaining the
upper gauge 9 with respect to the casting 33.
[0010] The core 8 is first removed from the resultant, incompletely cured casting 33 by
pulling up the jacket 7 together with the lower gauge 6 and the upper gauge 9 and
the pull rods 23 extending across the concrete mortar 10 of the casting 33 at eyelets
29 of the jacket 7 with the aid of an elevator crane 30, which conveys this assembly
to a second manufacturing site 2 and deposits it with the lower gauge 6 on a floor
31. Then the jacket 7 is removed from the still incompletely cured casting 33 and
from the lower gauge 6 and the upper gauge 9 retained therein by means of the pull
rods 23 of the positioning means extending` across the concrete of the casting 33
by loosening the bolt connections 21 and by pulling up the jacket 7.
[0011] In a further stage, after disengaging the upper gauge 9 from the lower gauge 6 by
unscrewing the pull rods 23 from the lower gauge 6 the upper gauge 9 is removed. After
complete curing of the concrete of the building element 3 the lower gauge 6 is removed.
[0012] Finally, subsequent to hardening of the castings 33 for example, by means of steam
in an autoclave (not shown) building elements 3 are obtained for composing a building
structure 32 as shown in Figure 4, for example, a tunnel, a culvert, a duct or a similar
structure consisting of a sequence of joined, box-shaped building elements 3.
[0013] The pipes 24 forming each a passage for a pull rod 23 and embedded at the corners
34 of the building elements 3 (Figure 5) can be used, in addition, for receiving stretching
cables 35 to intercouple the building elements 3. These stretching cables 35 are anchored
with bias tension at both ends of the tunnel 32 by means of cable anchors 36. The
joints 37 (Figure 5) between the contiguous building elements 3 comprise a ring 38
at one building element 3 for engaging a groove 39 of the other building element 3,
whilst the axial gap 40 accommodates an elastic sealing ring 41. It is thus possible
to deposit the building structure 32 on a weak underground 42, which tends to subside,
since the building elements 3 can turn relatively to one another whilst, however,
the water tightness of the joints 37 is maintained.
[0014] By using the method according to the invention it is ensured that the joint surfaces
of the building elements 3 which bound the gap 40 satisfactorily maintain their shape
during moulding despite the fact that the castings 3 are stripped of the core 8 and
the jacket 7 at an early instant so that they satisfactorily join one another.
[0015] The building elements 3 manufactured in accordance with the invention are generally
reinforced by one or more reinforcing steel networks 43. The reinforcing networks
43 as shown in Figure 7 are disposed in a mould cavity 4 and the upper gauge 9 of
the casting mould 5 is connected with said reinforcing networks 43 with the aid of
connecting means 44 of the positioning means consisting of anchors 45 welded to the
reinforcing networks 43 and placed in the mould cavity 4 and of a screw joint 46 for
each anchor 45.
[0016] During the removal of the core 8 and the jacket 7 the reinforcing networks 43 prevent
sagging of the non-cured concrete mortar 10, whilst the upper gauge 9 supports and
holds in place the joint surfaces 47. Likewise the lower gauge 6 maintains the model
of the joint surfaces 48 on the lower side. The connection between the lower gauge
6 and the casting 33 is automatically established since the casting 33 continues bearing
on the lower gauge 6.
[0017] If a building element 3 does not require a reinforcing network 43, it may be advantageous
for a simple, reliable and rapid manufacture to embed positioning anchors 49 in the
casting 33 by which the upper gauge 9 is connected with the casting 3 and by which
the occurrence of a crack 50 during the removal of the core 8 and the jacket 7 is
avoided. The lengths of the anchors 49 are chosen so that the zones of imminent cracks
50 are bridged by the anchors 49. The anchors 49, moreover, satisfactorily transfer
the vibrations of a vibrating device 13 arranged on the upper gauge 9 to the concrete
mortar 10. The concrete mortar 10 of the lower end of the casting 3 is satisfactorily
consolidated particularly by means of the vibrating device 17, whilst the vibrating
device 13 particularly consolidates the upper concrete mortar 10, where the effect
of the vibrating device 17 is reduced.
[0018] In the method illustrated in Figures 10 and 11 first the core 8 is removed from the
casting 33 by pulling upwards the latter together with the lower gauge 6, the upper
gauge 9 and the jacket 7 by eyelets 29. The upper gauge 9 is retained on the casting
33 provided with reinforcing networks 43, since it is pressed down on the concrete
mortar 10 by screws 51 supported on the jacket 7 and forming positioning means. Figure
11 shows that subsequently at a second manufacturing site 2 the jacket 7 is removed,
however, not until has the upper gauge 9 been positioned with respect to the lower
gauge 6 with the aid of positioning means 52 extending in the box-shaped channel 53
of the casting 33 and consisting of posts 55 anchored in the floor 54 of the manufacturing
site 2, said posts being provided at the top ends with pivotable, horizontal supports
56 having pressure screws 57 for pressing the upper gauge 9 against the concrete mortar
10 of the casting 33 so that the upper gauge 9 is positioned with respect to the casting
33 and with respect to the lower gauge 6 supporting said casting 33 and lying on the
bottom 54.
[0019] Conversely, it is as an alternative possible to first remove the jacket 7, whilst
the upper gauge 9 is retained by positioning means with the aid of the core 8 with
respect to the casting 33, after which the core 8 is removed, however, not until has
the upper gauge 9 been positioned with respect to the lower gauge 6 by means of posts
extending outside the casting 33.
1. A method of manufacturing a box-shaped building element in which on a first manufacturing
site concrete mortar is poured and consolidated by vibrations or shocks in the cavity
of a casting mould consisting of a lower profile gauge, a jacket, a core and an upper
gauge and in which the resultant, incompletely cured casting is removed from the core
or from the jacket and is transported together with the jacket or the core respectively
to a second manufacturing site, after which the jacket or the core respectively is
removed from the still incompletely cured casting, characterized in that the casting
together with the upper gauge and the lower gauge is removed from the jacket or the
core respectively, whilst at least the upper gauge is retained with respect to the
casting with the aid of positioning means.
2. A method as claimed in claim 1, characterized in that the upper gauge is connected
by the positioning means with the lower gauge and the casting together with the upper
and lower gauges interconnected by the positioning means is removed from the core
and the jacket.
3. A method as claimed in claim 1, characterized in that into the mould cavity are
arranged connecting members of the positioning means and the casting together with
the upper and lower gauges interconnected by the connecting members then extending
across the concrete of the casting is removed from the core and the jacket.
4. A method as claimed-in claim 3, characterized in that a number of pipes reserving
each a passage for a con- .necting member forming part of the positioning means are
arranged in the mould cavity.
5. A method as claimed in claim 3 or 4, characterized in that a reinforcement is arranged
in the mould cavity for the building element and in that the upper gauge is connected
with the reinforcement by means of connecting members of the positioning means.
6. A method as claimed in claim 1, characterized in that first the.core is removed
whilst the upper gauge is retained by positioning means with the aid of the jacket
with respect to the casting, after which the jacket is removed subsequent to positioning
of the upper gauge with respect to the lower gauge by means of connecting members
extending inside the box-shaped channel of the casting or in that first the jacket
is removed whilst the-upper gauge is retained with respect to the casting by positioning
means with the aid of the core, after which the core is removed subsequent to positioning
of the upper gauge with respect to the lower gauge by means of connecting members
extending outside the casting.
7. A method as claimed in anyone of the preceding claims, characterized in that the
upper gauge is pressed against the concrete mortar present in the mould cavity and
the concrete mortar is consolidated by means of a vibratory device arranged on the
upper gauge.
8. A building structure e.g. tunnel, sewer, culvert, composed of a sequence of contiguous
building elements manufactured each by a method as claimed in anyone of the preceding
claims.
9. A building structure as claimed in claim 8, characterized in that the passages
of the building elements manufactured by the method claimed in claim 4 are in line
with one another and receive stretching cables for intercoupling said building elements.