EP0593009A1

EP0593009A1 - Improved method and form-work particularly for the realization of columnar elements in concrete

Info

Publication number: EP0593009A1
Application number: EP93116493A
Authority: EP
Inventors: Giorgio Piovesan
Original assignee: ARBLOC Srl
Current assignee: ARBLOC Srl
Priority date: 1992-10-16
Filing date: 1993-10-12
Publication date: 1994-04-20
Also published as: ITTV920119A0; ITTV920119A1; IT1257722B

Abstract

Improved method and form-work particularly for the realization of columnar elements in concrete, of the types composed from two complementary half-shells (1,1'), for each of these at least two elements previously associated, providing:

a conveniently formed metallic external first element (4);
a second inside element associated to the first being obtained in polystyrene foam (3);
eventual third elements (2), associated on the internal side of the second, being composed from a suitable coating able to confer a certain form onto the visible surface face;

said half-shells to be coupled in contraposition and so held by clamping means (7).

Description

This invention as a subject has an improved method and form-work particularly for the realization of columnar elements in concrete. The innovation finds particular even if not exclusive application in the building sector, in the case of shaping column types.
In the construction of buildings, columns and pillars in reinforced concrete form part of the State of the art, some necessary structurally, others less so having in such cases a predominantly aesthetic character, but not excluding however the union of both these characteristics. In general, the surface of these may be obtained according to two forms, smooth or faceted, which are naturally determined from the form-work used during the shaping procedure. Even the section can vary, from square to essentially round, the last one realizing the tendency of the last generation of constructions to give parity of performance with a reduction in the cost of raw material.
At the present state of technology similar form-work is known, which, once erected has the function to maintain the form of the fresh concrete poured within until it has set, to then be dismounted.
Traditionally a previously used system foresaw form-work in wood, reconstructed on site by joiners or carpenters of the firm, which was predominantly composed from an ensemble of longitudinal staves ringed by semicircular elements and the whole closed externally by a generally square frame. Disadvantages obviously noticeable in such a solution consist in the execution costs of the work and in the time required, requiring a notable expense, from the workers, also in the dismounting and in the successive maintenance of used elements. Often furthermore the handicraft character of the form-work can produce gaps between the staves which allow the poured cement to penetrate and so above all under the qualitative profile, negatively affect the aspect of the finished product.
A second system used, that has found wide acceptance, has provided the adoption of form-work preformed in metal. The system introduces a new work method, eliminating some of the noticeable problems in the preceding solution and in particular relative to the costs and times, deriving mainly from realization and installation of the form-work in position, or directly in the yard. More in particular two symmetric half-shells are used, previously obtained and reutilizable, having a semicircular conformation, internally smooth, and coupled one with the other in contraposition for the realization of a column with a round conformation. The typical fixing is obtained by means of traditional bolts that transversely intersect the longitudinal edge, protruding in respect to the section, of both half-shells. However also in that case there are drawbacks, which regard in principle the difficulty of movement , for their larger weight, and also long installation times.
Finally, another drawback would consist in the fact that they do not appear versatile, being limited to the formation of smooth columns.
With the aim to consent a greater versatility, for example in the realization of columns with a visible faceted face, some form-work in high density polystyrene foam has been prearranged. Even these are composed of two half-shells to be coupled in contraposition, the internal surface of which, each one being essentially semicircular in section, may be easily coated both with a smooth plastic film, or with other coatings for example in wood (planed or sanded). These last ones are composed from an ensemble of longitudinal staves one contiguously joined to the other, and glued on the internal surface of said polystyrene form, which instead is externally square, in such a way that by joining the two parts it is possible to obtain a nearly square form. If on the one hand said form-work is more easily transportable due to its reduced weight, and more versatile for the possibility to form different columns, on the other hand other drawbacks are disclosed. In this case, they consist in the fact that to be erected they require the adoption of a complex structure needing firstly longitudinal stiffening panels and then a multitude of equidistant ties that would have the task of ringing the entire structure thus holding in position said polystyrene forms. Consequently the installation times will be equally long, necessary both for erection and dismounting, which must of necessity affect relative costs.
Finally, of decidedly more recent conception, the so-called disposable form-work is well known. These are composed of a tubular spiral structure, pre-coiled, made fundamentally of cardboard, some externally waterproofed, others coated internally in aluminium. In such a case they do not need to be reinforced as they are ready for use, however they are not exempt from drawbacks. They in fact do not consent the realization of columns in particular forms as they are limited to the realization of a round section. In the second place, the majority presents more than a few difficultiesd during dismounting, requiring from the operator particular effort and equipment for the procedure of the tearing of the cardboard, so much so that many manufacturers are concentrating on the search for valid solutions, some already achieved, to allow for an easier dismounting. Other problems again are verified in the ugly aesthetic form, typically spiral-shaped for the entire height of the column which the internal shape of the disposable form-work confers to the column so poured. The last drawback consists also in the fact that the form-work, being destined predominantly for use by buildings yards, often remains unused for long periods, and so, coming into contact with bad weather conditions, can easily deteriorate, and so weaken their structure.
Aim of the present invention is also to obviate the above-mentioned inconveniences.
This and other aims are reached with the present innovation according to the characteristics of the included claims solving problems exposed by means of an improved method and form-work particularly for the realization of columnar elements in concrete, of the types composed from two complementary half-shells, each of which comprises at least two elements previously associated, providing:

an external metallic first element with semicircular section;
a second element associated internally to the first being obtained in polystyrene foam, also having a semicircular section;
eventual third elements, associated on the internal side of the second, being composed from an ensemble of staves, in this case of types of wood, disposed longitudinally and/or providing, in place of the former a film of plastic material;

In such a way through the notable creative contribution whose effect realizes all immediate technical progress different advantages are achieved amongst which it is possible to cite the fact that they consent a more rapid installation, speeding up the erecting phase and the successive dismounting. They are furthermore easily movable and particularly resistant to climatic conditions, and in the second place they are provided with an undoubtable versatility, with decidedly contained costs, being able to be used indifferently for the formation of columns with round sections or more complex forms, for example with a visibly faceted face. Finally they are able to confer a valuable aesthetic effect with high finishing levels.
These and other advantages will appear from the successive specified description of preferential realization solutions with the help of the schematic drawings attached whose execution particulars are not to be considered limitative but only illustrative.
Figure 1 represents a perspective view of a complete form-work, installed.
Figure 2 represents a view, always in perspective but of only one of the two half-shells that compose the form-work of the Figure preceding .
Figure 3 represents a view, again in perspective, of a column, in this case of the types with a visibly faceted face, obtained by means of the use of the form-work of Figure 1.
Figure 4 represents a sectional view of a half-shell taken through the plane A-A of Figure 2.
Finally, Figure 5 represents an expanded view of different components that participate in the formation of at least one of the two half-shells.
Referring also to the Figures, it is disclosed that a form-work (A), in order to obtain the columns in concrete of the type with a visibly faceted face (B), is composed of two complementary half-shells (1, 1') each one having a semicircular section, in such a way that once joined in contraposition they complete an essentially circular section.
Every half-shell (1, 1') is composed structurally of at least two elements conveniently sandwiched together and eventually a third destined to confer a more or less particular form on the visible surface of the column (B) to be so obtained. Said elements, consist in a first external sheetplate (4) of a minimum thickness having a semicircular section and inside this a polystyrene form is provided (3) this also having a semicircular section, destined eventually to support, on the concave surface, a coating, that in such a case may be formed from an ensemble of longitudinal contiguous staves (2), in this case of wood.
More in particular, the illustration of a realization process for at least one of the half-shells (1, 1'), can foresee that in the first place one proceeds to the joining of a plurality of staves (2), by means of stapling, conferring to them a semicircular form. Then one carries out the cutting of the high density polystyrene foam, also in such a case according to a monolithic semicircular (3) form. In a further preferential solution the polystyrene form (3) may be obtained even from more components conveniently associated along the edges, each one concerning a certain portion of semicircle. Such a case would allow the coating in wood (2), later to be coupled, a greater easy of adaptation to the concave form of the polystyrene form (3), absorbing its expansions. Again in another preferential solution, along both longitudinal edges of the semicircular form in polystyrene (3), are carved grooves (3') dimensionally sufficient to receive at least the half of a junction stave (5) of the fixed joint between the two half-shells (1, 1'). Furthermore the semicircular calendering and the cutting of the external sheetplate (4) is done, to then pass to an assembly phase.
Elements previously obtained, that compose at least one of said two half-shells (1, 1') are coupled by sandwiching them together, interposing polyurethanic glue (6) between them and introducing them in a press to be held in form for a determined period. They are finally subjected to a finishing phase that in such a case can consist in the trimming of the respective edges.
For installation it will be sufficient to bring together vertically in contraposition the two half-shells (1,1') taking care that the junction staves, (in this cast two, one for each side) is inserted correctly in the respective places (3'). At this point the only thing left for the operator to do will be to associate the collars (7) in a ring fashion, so that they can be hooked and tightened to the wanted size.

Claims

Improved method and form-work particularly for the realization of columnar elements in concrete, of the types composed from two complementary half-shells, and characterised in that it comprises for each one of these at least two elements previously associated, providing:
- a conveniently shaped external metallic first element ;

- a second element associated internally to the first being obtained in foam polystyrene;

- eventual third elements, associated on the internal side of the second, being composed of a suitable coating able to confer a certain form onto the visible surface;
said half-shells to he coupled in contraposition and held by means of clamping.
Form-work according to claim 1., characterised in that it is composed of two complementary half-shells (1, 1') each one comprising at least two elements previously associated, which are:
- a metallic external first element with semicircular section (4);

- a second internal element associated to the first and made of polystyrene foam, also having a semicircular section (3);

- eventual third elements, associated on the internal side of the second, being composed from an ensemble of staves, disposed longitudinally (2, 2', 2'') and/or providing, in place of the first, a film of plastic material ; and clamping means for said two coupled half-shells (1, 1'), composed from collars (7) which can be hooked rapidly and progressively tightened.
Form-work according to preceding claims, characterised in that in a preferential solution the polystyrene form (3) is obtained from a greater number of longitudinal components conveniently associated along their edges, each one concerning a determined portion of the semicircle .
Form-work according to preceding claims, characterised in that along both longitudinal edges of the semicircular polystyrene form (3), grooves (3') are carved so as to receive a stave (5) for a fixed joint between the two half-shells (1, 1').
Form-work according to preceding claims, characterised in that the elements previously obtained, that compose at least one of said two half-shells (1, 1') are coupled by sandwiching them together, interposing polyurethanic glue (6) between them and introducing them in a press to be held in form.
Form-work according to claims 1. and 2., characterised in that the third elements, associated on the internal side of the second, are composed of an ensemble of wooden staves disposed longitudinally and contiguously to each other (2, 2'').