EP3020886A1

EP3020886A1 - Method for fabricating a wall or walls of a building by casting, and a form system

Info

Publication number: EP3020886A1
Application number: EP14193450.5A
Authority: EP
Inventors: Petri Varonen
Original assignee: Savolin-Aarva Heidi; Wiirilinna Tero
Current assignee: Savolin-Aarva Heidi; Wiirilinna Tero
Priority date: 2014-11-17
Filing date: 2014-11-17
Publication date: 2016-05-18

Abstract

Method for fabricating a wall or walls of a building by casting into a form at the construction site. The invention is implemented such that form sections that are fabricated and prepared in a production plant and can be joined together are used as forms, which are joined into a single assembly at the construction site and which after that are cast. The object of the invention is also a form system.

Description

The object of the present invention is a method for fabricating a wall or walls of a building by casting into a form at the construction site. The object of the invention is also a form system.
A drawback of ganged form systems known in the art that can be mentioned are the holes penetrating a structure that are at relatively dense intervals, said holes being caused in a wall structure by the form ties needed to join together the separate form walls to be used in the structure, as well as the nails remaining in the finished structure caused by the spacers to be used in the reinforcing work, which nails must be removed afterwards. The nails to be used in fixing the spacers also cause continuous wear on the plywood sheathing of ganged form systems known in the art.
Also, e.g. implementing door openings and window openings causes corresponding problems in conventional ganged form systems owing to the nail fixing of void boxes. Disassembling a conventional form is also made difficult for the aforementioned reasons. That being the case, implementing a finished fair face concrete surface is impossible to realize with prior-art ganged form systems.
Ganged form systems known in the art are supported in a vertical attitude with the external sloping braces of the formwork, the fixing of which braces to the vaultings is often awkward due to lack of space. In addition, the braces have to be disassembled once and made on the perimeter wall structures.
In ganged form systems known in the art worksite crane costs and worksite logistics costs are extremely high.
A problem with the state of the art is that the heating arrangements for a concrete casting are difficult to implement because separate heating wires must be installed at the construction site in the concrete reinforcement, which wires remain in the finished structure. In addition, after concrete casting the structure must be protected with a cover, inside which fan heaters are placed. Also post-cast monitoring causes work.
In ganged form systems known in the art protection against falling is lacking from the opposite side of the concrete casting scaffolding during the casting work. At the point of the finished structure the scaffolding is installed in the conventional fixing style by the client, in which case there is a delay in the protection against falling.
For the aforementioned reasons, the construction costs of concrete structures to be cast in situ and to be implemented with conventional ganged form systems rise to be extremely high.
It is known that a form can also be made from timber. The problems of a prior-art timber-structured one-off mold for in situ concreting are, in addition to the aforementioned problems of prior-art ganged form systems, the large quantity and short lifetime, i.e. wastage percentage, of timber materials used for construction, and the very large amount of work at the construction site, in which case the timetable is longer than before and the costs are higher.
Owing to the problems described above, the building of a multistorey apartment block is mainly implemented as construction with precast concrete members, and the construction of a single-family house of so-called stone construction with various small building components and to some extent with larger precast concrete members.
Problems are also attached to precast concrete members prefabricated in a factory. One problem is the abundant quantity of vertical and horizontal joints in the members, which creates a requirement for a lot of finishing work. In addition, they weaken the structure and require servicing in the future. Implementing a fair face concrete surface is impossible owing to the jointed structure. This significantly increases the costs of finishing work.
Another problem is the numerous vertical supportings of precast concrete members with sloping braces.
The transportation costs of precast concrete members are high owing to their large mass. Also logistically the transportation of them is disadvantageous, because the transporter drives back empty. The large mass of precast concrete members also causes limitations in the dimensioning of the precast concrete members.
A problem in prior-art stone-structured single-family houses, for their part, in addition to some of the problems mentioned earlier, is that there is a large number of insulation joints in structures implemented with insulated concrete molded breeze blocks, in which case a lot of grouting foam must be used and the installation must be carefully performed. Monitoring this is extremely awkward for the client and is resolved afterwards only with e.g. thermal camera measurements. Heat bridges detected afterwards are almost impossible to repair at reasonable cost. One problem is also the long working hours at the construction site, which incurs high costs. In addition, a large amount of finishing work, such as rendering, is needed
The aim of the current invention is to achieve a new type of method for making a wall mold. In addition, the aim of the current invention is to achieve a new type of form system. The invention is characterized by what is mentioned in the claims.
With the invention insulated and uninsulated reinforced concrete wall structures that are to be concreted at the construction site, said structures being free of joints and having fair face surfaces, are produced with steel form sections fabricated in factory premises, which structures are joined into a single assembly at the construction site.
The invention is a product differing significantly from ganged form systems known in the art in terms of its details, its technical functionality and its operating model. The invention also brings a cost-competitive alternative to prior-art precast concrete member solutions, concrete molded block solutions and timber-structured one-off mold solutions with conventionally high-quality in situ concreting technology.
The operating principle of the invention is as follows:

In a production plant a preassembled magazine unit (insulations, steel reinforcing, opening voids, et cetera) is assembled into a single assembly on top of an underframe designed for the purpose. Next, the form section, opened at the bottom part, is lifted with a hoist onto the preassembled magazine unit and tightened with tiedown bolts, in which case the preassembled magazine unit is anchored together with the form section into a single assembly. A number of form sections can, if necessary, be joined together already in the production plant. The form section of the first storey preferably also comprises a plinth structure.

After this the loaded form sections are transported to the construction site and installed with a crane into their positions according to the formwork plan and joined into a single form assembly. Next the casting scaffolding and railing poles are placed in the fasteners that are ready on the outside edge of the form and the railings are installed.
After that the form sections are adjusted into a vertical attitude with the adjustment mechanism of the top fixing member, after which the concrete casting work can be performed.
After sufficient strength development (approx. 2 days) of the concrete casting, the bottom fixings of the form sections are opened and the form sections are removed from on top of the concrete wall, in which case the magazine part remains as a part of the wall structure, which is tight, smooth and free of joints apart from one horizontal construction joint e.g. between the storeys in a multistorey dwelling site. Construction joint beading that is known in the art can be used in a construction joint.
After this the railing poles are transferred into the pole holders pressed into the concrete casting in the top end of the exterior shell of the cast wall, in which case the protection against falling is ready e.g. when installing the hollow-core concrete slabs of the next storey.
Finally, the form sections are lifted onto the cargo space of a transporter and taken to the production plant or transferred to a storage area and transported, for repacking, to the production plant on the return haulage of the transporter delivering the loaded forms of the next storey.
The transporter is able to transport a large number of forms at a time owing to the relatively lightweight structure, which when compared to a precast concrete member is e.g. approx. ¼ of the weight of the product in question.
Also, it is possible to implement e.g. the dividing walls of a multistorey dwelling with loadable self-standing magazine form technology owing to the adjustable wall thickness.
In the loadable self-standing magazine form according to the invention, spacer bolts are not used except in the form containing the plinth of the first storey. The spacer bolt is located on the bottom edge of the form at a distance of approx. 10 cm from the footing and the hole from it that remains in the structure is insignificant because of the thermal tar coating and welded plinth strip that will come on top of it. A wall structure implemented in this way is free of joints and smooth owing to the steel plate form surface. Sharp-ended spacers are fastened into the insulation, and steel reinforcements into the spacers, and the aforementioned assembly is anchored with through-bolts coming into the bottom edge of the form.
In a floor form the principle is otherwise the same, but the locking takes place with thin ties circling the bottom of the insulation and the reinforcing, which ties are locked at the top end of the form and pulled out after installation of the form section at the construction site. The form is locked at the one end with a locking member during transportation, which locking member is removed after installation of the preassembled magazine into its position. A floor form means the form system after the first storey.
The door voids and window voids are fixed to the opening cut in the insulation with grouting foam and locked with the other materials inside the form, in which case a nail fastening is not needed. In the form system according to the invention a top fixing member adjustable with a pinion and lockable with bolts is on the top part, which member is adjusted with a key designed for the component.
If necessary, thermal insulation is prepacked inside the form in the production plant.
The problem relating to the heating arrangements of concrete casting is resolved in the invention in such a way that 1-2 cm of polyurethane insulation is sprayed onto the perimeter walls of the form. In addition, thermal resistors are already in the structure. Only some of the corner forms must be protected with a cover, but heating resistors can, if necessary, be preassembled in these too.
In the magazine form according to the invention the railing pole fasteners are ready on the outside edge of the form and after the casting - while the concrete is still soft - the fixing cups are pressed into the top part of the outside shell, into which fixing cups the railing poles are transferred after the drying of the concrete and the removal of the form.
As stated earlier, the loadable, self-standing magazine form system that is packed in a production plant is transported to the construction site and installed into its position, after which the form is adjusted and cast. After this, the form is opened at its bottom part and removed, in which case the timetable is fast owing to the small amount of installation work to be done at the construction site.
As a result of the aforementioned facts, with the form system according to the invention a wall structure that is concreted in situ and that has a fair face surface can be implemented extremely cost-efficiently and with high quality.
The weight of the magazine form system according to the invention is only approx. ¼ of the weight of a corresponding precast concrete member, so that the transfer and installation of also larger assemblies of joined sections succeeds easily and the transporter can take more of a load on board. In addition, the transporter can take the form equipment of the previous storeys on board on the return journey, in which case the transporter does not need to drive back empty.
In the following, the invention will be described in more detail by the aid of some preferred embodiments with reference to the attached drawings, wherein

Fig. 1 presents a rear view of a form section according to the invention,
Fig. 2 presents a cutaway of a plinth form,
Fig. 3 presents a top view of a form,
Fig. 4 presents a corner form,
Fig. 5 presents a top view of a corner form,
Fig. 6 presents the adjustment parts of a corner form,
Fig. 7 presents the bottom part of a floor form,
Fig. 8 presents the bottom part of a floor form,
Fig. 9 presents the vertical adjustment mechanism of a form section,
Fig. 10 presents the same as Fig. 9, but as viewed from above,
Fig. 11 presents the principle of loading a preassembled magazine,
Fig. 12 presents also the principle of loading a preassembled magazine,

Fig. 1 thus presents a wall 1 of a steel form section according to the invention. It is composed of a steel plate, onto the rear surface of which vertical and transverse structural hollow sections are fixed by welding. There are two units of these walls in each form section, said units facing each other.
The bottom fixing bolts of the form of the plinth template are marked with the reference number 8, with which bolts the preassembled magazine part is connected inside the form section and the bottom part of the form section is fixed together. The bolt passes inside a protective tube, in which case it can be removed from the finished final product.
The bolts fixing the form section to the ground support, for their part, are marked with the reference number 9.
Fig. 1 further presents the bayonet connection counterparts 10 welded to the structural hollow sections on the end of a form section, to which counterparts the form section to be installed next connects. The fixing members 11, which connect the form sections to each other at their top end, are situated on the other end of the section. They connect to the top end of the previously installed form section with a bolt fixing 15. The fixing member 11 prevents the section from moving upwards as well as in the lateral direction.
Brackets 12 for the railing poles are fixed to the outside edge of the outer wall of the form section, in which brackets the railing poles and safety railings are placed after installation of the section.
The reference number 14 presents lifting lugs, by means of which the form section is lifted.
Cavities 16, 17 are made in the bottom part of a floor form section. Of these, the reference number 16 refers to the installation cavity of the fasteners to be bolted to the construction-time support of the outer wall of the floor form section, said fasteners remaining in the finished final product. The reference number 17, for its part, refers to the cavities of the quick-coupling fasteners for the construction-time support of the exterior wall of the floor form sections, said fasteners remaining in the finished final product.
The transport-time locking part of a floor form section is marked with the reference number 25.
Fig. 2 presents a cutaway of a plinth form. Again there are two walls 1 facing each other in it. In the top part of the form is a mechanism for adjusting the vertical attitude of the form section. The adjustment mechanism comprises a pinion on a bearing and the shaft 2 of said pinion. The adjustment mechanism further comprises a support member 3 that is below the pinion shaft and fixed to the form section, which support member is provided with toothing, which is in connection with the pinion 2, enabling adjustment. This arrangement is also evident from Fig. 3 and, on a larger scale, also from Figs. 9 and 10.
The bottom support member to be fixed on the form wall, on the facade side of the form section, is marked with the reference number 4 (Fig. 2), which member is joined with a bolt on a bearing to the top fixing member 5. The top fixing member 5 joins the form walls 1 to each other and it has a changeable center part lockable with a cotter pin fixing for adjusting the wall thickness. The top fixing member 5 is provided with toothing on the pinion shaft 2 end, the pinion 2 being in connection with said toothing, enabling adjustability.
From Fig. 2 the locking bolt 6 (2 units) is also seen, with which bolt the form is locked after adjustment.
Fig. 3 thus presents a top view of a form section. The adjustment mechanism described above is evident from it. The brackets, marked with the reference number 13, of the railing poles to be pressed into the concrete casting of the exterior shell after the casting work are also seen in it, in which case after removal of the form sections the railing poles and safety railings that were on the outside edge of the form can immediately be transferred into the brackets of the outer concrete shell. In this case the protection against falling remains during the installation of the hollow-core concrete slabs and other work phases. When installing the form sections of the next storey the railing poles are lifted out of the brackets pressed into the exterior shell and installed again after the fixing of the form sections of the next storey in the brackets 12 of the exterior edge.
On the left edge of Fig. 3 the fixing points 15 of the bolts of the fixing members preventing upward and lateral movement of the form sections are visible.
Figs. 4-6 present a corner form that is adjustable in its angle. The corner mechanism as a whole is marked with the reference number 20. It comprises two vertical hollow sections of structural steel that are joined together, of which one is provided with a flat lug part and the other with a smaller round inner tube welded inside the structural hollow section, which inner tube passes through the apertures of the flat lug parts, and the hollow sections are joined into a single moving assembly with a bolt the length of the form height passing inside the inner tube. The corner mechanism is also provided with two inner tubes in both ends and with corresponding bolts, in which case the adjustment functions and the structure can be locked with the bolts on the top side. A necessary amount of horizontal incisions are cut in the structural hollow section provided with two inner tubes for the lug parts of the adjacent hollow section.
The telescopically adjustable horizontal supports are marked with the reference number 21, which supports are welded at their ends to the corner mechanism and to a first vertical hollow section, in which case the length of the outer walls can be adjusted.
Further, the slide rails for the fixing of a steel plate are marked with the reference number 22, which slide rails are installed in the framework horizontally. The reference number 23 refers to the vertical hinging of the inside wall of the form section, to which hinging the form walls are fixed. The hinge 24 is openable.
Figs. 7 and 8 present the bottom part of a floor form and its support. The reference numbers 18 and 19 present the construction-time support of the floor form section, said support being fabricated from stainless steel, and the fixing member binding the outer concrete shell to the framework, said member remaining in the finished final product. The fixing member is fixed by bolting to the top end of the cast exterior shell and to the hollow-core concrete slab or other vault structure at the point of the continuing wall structure, in which case the bolts remain completely covered by concrete.
The form section is placed into its position and bolted into this fixing that is situated, as viewed from inside the building, on the right-hand side edge, which can be performed without working on the outside of the form. The bolt fixing prevents the rising of the form section upwards on the right-hand edge and the fixing member according to the reference number 11 on the left-hand edge, where the previous form section is fixed in a corresponding manner from the right-hand edge.
The bolt fixing and the jaw structure installed on the outside edge of the support member together hold the form wall in its position against the casting pressure. The protrusion part of the support member is afterwards cut off the finished end product.
Figs. 11 and 12 present a preassembled magazine unit, which is installed inside a form section by lifting the form section onto the finished preassembled magazine unit, as stated earlier. The preassembled magazine unit is packed onto a packing underframe 26. It is known that a preassembled magazine unit can comprise insulation 27, reinforcement elements 28, a form spacer 29 and a timber reveal for the opening voids for doors and windows, et cetera. The timber reveal, of longlife wood, of the door opening is marked with the reference number 30. The reference number 31, for its part, refers to the opening void structure during the casting.
It is obvious to the person skilled in the art that the invention is not limited to the embodiments described above, but that it can be varied within the scope of the claims presented below.
The characteristic features possibly presented in the description in conjunction with other characteristic features can if necessary be used separately to each other.

Claims

Method for fabricating a wall or walls of a building by casting into a form at the construction site, characterized in that form sections that are fabricated and prepared in a production plant and can be joined together are used as forms, which are joined into a single assembly at the construction site and which after that are cast.
Method according to claim 1, characterized in that in a production plant a preassembled magazine unit, which comprises e.g. insulations (27), reinforcement elements (28), opening voids (31), et cetera, is assembled into a single assembly, an open form section is lifted from the bottom part onto the preassembled magazine unit and these are fixed together.
Method according to claim 1 or 2, characterized in that a number of form sections are joined together already in the production plant before transportation to the construction site.
Method according to any of claims 1-3, characterized in that at the construction site before casting the casting scaffolding and railing poles are placed in fasteners (12) on the outside edge of the form and the railings are installed.
Method according to any of claims 1 - 4, characterized in that before casting the form sections are adjusted into a vertical attitude with an adjustment mechanism belonging to the form system.
Form system for casting a wall or walls of a building at the construction site, characterized in that the form system comprises at least two form sections, which are fabricated and prepared for casting in a production plant and transported to the construction site for in situ casting, and which are joined into a single assembly before casting.
Form system according to claim 6, characterized in that a number of form sections are joined into a single assembly already in the production plant and are transported as such to the construction site.
Form system according to claim 6 or 7, characterized in that a form section comprises two walls (1) facing each other and at a distance from each other, which are steel plates.
Form system according to any of claims 6-8, characterized in that the vertical attitude of a form section can be adjusted with an adjustment mechanism.
Form system according to claim 9, characterized in that the adjustment mechanism comprises a fixing member (5) connecting the walls of a form section, which fixing member is fixed at one end with a bearing to a bottom support member (4) fixed to one wall and at the other end to a support member (3) fixed to a second wall.
Form system according to claim 10, characterized in that on the ends of the fixing member (5) and support member (3) are toothings, which are in connection with a pinion (2) arranged on the bearing point of the fixing member and support member.
Form system according to any of claims 9-11, characterized in that the adjustment is locked with a locking bolt (6), which locks the fixing member (5) to the end of a wall (1) of a form section.
Form system according to any of claims 6-12, characterized in that the form system comprises a corner mechanism (20), by means of which the angle of the form can be adjusted before casting.
Form system according to claim 13, characterized in that the corner mechanism (20) comprises two vertical hollow sections of structural steel that are joined together, of which one is provided with a flat lug part and the other with a smaller round inner tube welded inside the structural hollow section, which inner tube passes through the apertures of the flat lug parts.
Form system according to claim 14, characterized in that the corner mechanism (20) is provided with two inner tubes situated in both ends and with corresponding bolts, in which case the structure can be locked with the nuts of the top side.
Form system according to claim 15, characterized in that a necessary amount of horizontal incisions are cut in the structural hollow section provided with two inner tubes for the lug parts of the adjacent hollow section.
Form system according to any of claims 13-16, characterized in that a corner mechanism (20) also comprises telescopically adjustable horizontal supports (21), which supports are welded at their ends to the corner mechanism and to a first vertical hollow section, in which case the length of the outer walls can be adjusted.
Form system according to any of claims 13-17, characterized in that a corner mechanism (20) also comprises slide rails (22) for the fixing of a wall (1), said slide rails being installed horizontally in the framework.
Form system according to any of claims 6-18, characterized in that a preassembled magazine unit is installed inside a form section, which unit is installed on a packing underframe (26).
Form system according to claim 19, characterized in that a preassembled magazine unit comprises various additional properties, such as insulation (27), reinforcement elements (28), form spacers (29) and opening voids (31) for doors and windows.