A box molding process for realizing projecting elements in reinforced concrete and a molding system therefor

Abstract: The invention relates to a molding system for realizing projecting elements in reinforced concrete, and comprises a bracket (6) to which a support bracket (8) is rotatably constrained, which bears a squaring beam (9). The system further comprises a molding slab (10), extremities of which rest respectively on the squaring beam (9) and the bearing structure (2). Also described is a box molding process comprising the phases of positioning of a support (3) provided with a pivot (4) on a bearing structure (2) and insertion of a tie-rod (5) on the bearing structure (2), and a constraining and positional adjustment of the bracket (6). The process also includes a phase in which a support bracket (8) is positioned and constrained to the bracket (6) by means of insertion of at least a plug (12), and a phase of placing a squaring beam (9) between the bracket (6) and the support bracket (8); and insertion of a molding slab (10) between the support bracket (8) and the bearing structure (2). Also comprised are phases of dismounting, with the disengaging of the support bracket (8), and an externalwise rotation of the support bracket (8) with recuperation for further utilization of both the bracket (6) and the support bracket (8).

Description: DESCRIPTION The present invention relates to a box molding process for realizing projecting elements in reinforced concrete, and a molding system thereof, in particular for building elements for bridges, viaducts and roofs. The prior art teaches various systems for realizing projecting elements: the projecting beams, however, are always of limited dimensions due to the considerable difficulties involved in making them. A first building method proposes the use of special reinforced supports equipped with trestles, which are fixed to an underlying bearing structure, such as a beam, a box-shaped element or the like. The drawback of the above system is that the trestles are expensive. Further, it is considerably difficult to set and place the trestles due to the presence of reinforcement rods projecting from the underlying structure. A further drawback inherent in the above system is the difficult of positioning the reinforcement rods due to their having to pass through the inside of the stirrups of the trestles, a time-consuming task. A still further inconvenient is the occurrence of uneven settling during the concrete casting operation. This unevenness leads to incorrect alignments of the trestle caissons, which are impossible to put right: consequently, a second operation is needed for setting the lateral wings. A second constructional system for realizing projecting elements involves the use of a projecting bridge system supported by a strut and tie-rod assembly. In more detail, this system requires the presence of a strut element extending vertically from the bearing structure, which strut opposite end is constrained on one side by a tie rod fixed to the underlying structure and on the other side by a free end of a projecting slab. This system also exhibits a series of problems, a first of which is the elevated deformability of the system, rendering the system utilizable only with limited-size projections. Further, the slab must be provided with attachments for anchoring the tie-rod; then, once the concrete has been cast and the slab rendered solid, the tie rods and cut and the attachments, being situated inside the setting concrete, are lost. A third constructional system for realizing projecting elements involves the creation of an external mold, supported by a scaffold. This system also incurs several drawbacks, among which are the lengthy construction of the scaffold, and the considerable costs connected with the sheer amount of specialized work needed for erection of a long scaffold at considerable height. A further construction system is illustrated in the U.S. patent n. 3.974.995 in which a system is described for the realization of vertical wall portions to close an area of space existing in a building between a floor and a ceiling for the realization of windows. The system presented in the patent cited comprises four panels which form the outline of the portion of wall to be realized. To support the panels, a plurality of elements are used, including: a pair of vertical props positioned between the floor and the ceiling, each one being engaged with a bracket which is positioned externally to the portion of wall to be realized, a frame with a right-angled triangular shape, with one vertical side which supports the panel, an angle inside the lower portion of the wall and a hypotenuse which extends from the base of the prop, up over the panel, towards the exterior of the building, until it reaches a support which holds the panels. The support has the shape of an upside-down L wherein one side of the L, the vertical side, engages with the panel, while the other side has, at the free end, a rope which is fastened to the bracket and is used to adjust the position of the external panel. In the corner of the support there is a gusset which is capable of holding a hook for removing the structure from the outside, once the portion of the wall has been completed. The system illustrated is particularly complicated and has some drawbacks. In fact, this system can be used to realize vertical wallportions with limited dimensions. The layout of the different elements does not allow a horizontal projecting element to be realized. Furthermore, the entire structure is only used to hold the panels which constitute the actual box-molding elements. The system illustrated is no more than a mobile box mold which is constrained between the ceiling and the floor, and the bracket and the support are used to hold the panels which constitute the container for the concrete jet. A still further system proposes the use of a slab supported by a bracket anchored to the side wall of the bearing structure. This system too is beset by drawbacks, among which are the considerable stress the bearing structure is subjected to. Further, significant difficulties have been encountered during the mounting and dismounting phases, not least of which is a considerable danger to life and limb especially during dismounting. Further to this is the impossibility to making small adjustment to the molding slab height before casting. The main aim of the present invention is to resolve the above-described problems inherent in the prior art by providing projecting elements of considerable size by means of a boxing system and process therefor which permits of varying the size of the projections of the concrete simply, without incurring increased manufacturing costs, and without any time-wasting. The invention is also easy to construct and use. A further aim of the invention is to provide a box mold system and realization process therefor which do not necessitate the use of massy and complex structures disturbing the insertion of the reinforcement rods of the slab, as happened in the prior art systems. A still further aim of the present invention is to obtain projecting elements having various geometrical and static properties, without having recourse to making alterations in the conformation of the box molds used. Further, with the process, correct positioning of the mold slab is ensured since the projections can be aligned and any height errors made during casting can be corrected, unlike in the prior art realizations. A further aim of the present invention is to realize a support structure for the mold box which can be saved after used and reutilized. A still further aim of the present invention is to realize the projections at contained cost with regard to the plant and the tools used, to better use of work time, considerable adaptability of use, and with regard to increased, indeed optimum safety for operations during both mounting and dismounting phases of the elements which constitute the projection mold box. These aims and others besides, which will better emerge during the following description, are attained by the process for box molding for realizing projecting elements in reiforced concrete, and a molding system therefor, in particular for building elements for bridges, viaducts and roofs, which is herein described in the form of a non-limiting preferred embodiment, made with reference to the accompanying figures of the drawings, in which: figure 1 is a frontal schematic view of the elements for realizing a molding system of the invention; figure 2 is a schematic view of a first operative phase of the process for obtaining a projection in reinforced concrete; figure 3 is a schematic view of a further operative phase of the process of the invention; figure 4 is a schematic view of a further operative phase of the mounting of the molding system; figure 5 is a schematic view of a subsequent operative phase of the process; figure 6 is a still further schematic view of a subsequent operative phase of the process; figure 7 is a schematic view of an operative phase of the process relating to the dismounting of the molding system according to the present invention; figure 8 is a schematic view of a further operative phase of the process; figure 9 is a schematic view of a phase relating to a finishing operation of the finalized reinforced concrete projection. With reference to the figures, and in particular to the figure 1, 1 denotes in its entirety a manufacture comprising a projecting element and relative box mold system according to the present invention. In particular, 2 denotes a bearing structure which can be a beam or a box-like structure for making bridges and/or roofing elements. The molding system used in the process of the present invention comprises a support 3 made in reinforced concrete and having a parallelepiped conformation. The support 3 is adapted to be located and/or anchored on the bearing structure 2 and the support 3 exhibits a pivot 4. The molding system also comprises a tie-rod 5 adapted to be constrained to the bearing structure 2 at a prefixed distance and a bracket 6 adapted to be positioned restingly on the pivot 4. In greater detail, the bracket 6 is provided at one end 6a with an i attachment element 5a predisposed to be constrained to the tie-rod 5 and at the other end 6b with a plurality of holes 7 arranged in two parallel lines and specially distanced one from another. Moreover, the molding system presents a support bracket 8 engaged to the bracket 6. The support bracket 8 is L-shaped, wherein a first arm of said L-shape is adapted to be constrained to the support bracket 8 by means of a pair of plugs 12 inserted in the holes 7, constraining thereby the support bracket 8 to the bracket 6 at a predetermined distance from the bearing structure 2, corresponding to the dimensions of the projecting elements to be constructed while the other arm of the L-shape constitutes the rest base at a squaring beam 9. In more detail, a first plug 12a serves to rotatably engage the support bracket 8, while a second plug 12b serves to block rotation thereof. A squaring beam 9 is adapted to rest on the rest base of the support bracket 8, and has the task of supporting a molding slab 10 the extremities of which are adapted to rest respectively on the bearing structure 2 and the squaring beam 9. The process of the present invention comprises a plurality of operative phases for realizing the molding, with the aim of constructing a projecting element of considerable dimensions on the bearing structure 2, and of dismounting the mold itself once the concrete cast and the concrete slab have hardened. The process, as can clearly be seen in figure 2, comprise a first phase in which a support 3 in concrete or like material exhibiting a pivot 4 on its summit is rested or anchored on the bearing structure 2. A tie rod 5 is constrained to the bearing structure 2 at a prefixed distance. Figure 3 illustrates a subsequent phase involving the positioning of a bracket 6 restingly on the pivot 4 and constrained to the tie-rod 5 by an attachment element 5a. By acting on the tie-rod 5 through the attachment element 5a the bracket 6 is adjusted, bringing it to the exact height required: this adjustment operation can be repeated during subsequent operative phases. Next, a support bracket 8 is positioned at a predetermined distance from the pivot 4, said predetermined distance depending on the length of the projection to be realized. The support bracket 8 is connected to bracket 6 by means of a first plug 12a which is inserted in a hole 7 and blocked by a second plug 12b which is inserted in another hole 7 arranged vertically with respect to the preceding hole 7. The following phase of the process involves the laying of a squaring beam 9, on the L-shaped element of the support bracket which represents the support base for the said squaring beam, between the bracket 6 and the support bracket 8, as shown in figure 4. Then the molding slab 10 is positioned, the ends whereof rest respectively on the squaring beam 9 and the bearing structure 2. At this point, the mold box for the projecting element is ready and the reinforcements can be arranged for the slab and projection. When the rods of the reinforcements have been positioned, the height of the future projection can one more be adjusted if necessary. At this point, the concrete can be cast into the mold constituted by the squaring beam 9, the molding slab 10 and the bearing structure 2, as shown in figure 6. When the concrete has hardened the support bracket 8 is loosened, removing one of the two plugs 12 by means of which it was constrained to the bracket 6. Once the plug 12b has been released, as shown in figure 7, the support bracket 8 is rotated such as to be distanced from the squaring beam 9. Figure 8 shows how the bracket 6 is removed: after having been detached from the tie-rod 5 and the support bracket 8, it is lifted while the tie-rod 5 and the pivot 4 are immersed in the cast. Finally, a lateral curb 11 can be made, already squared in the external side by of the squaring beam 9, meaning that it is sufficient to add a formwork containing element in the opposite internal side to complete the squaring of the lateral curb 11. The invention thus achieves its set aims. Indeed, a multiplicity of realisations can be achieved using the invention, all having different projection reaches thanks to the flexibility and practicality of use of the elements composing the molding system of the invention. The process according to the invention obviates all the drawbacks in the prior art and does away with the need for awkward trestles while allowing for great simplicity in the arranging of the reinforcing rods in the mold slab. Further, the process of the invention enables repeated aligning of the projections and therefore correction of small height errors, considerably reducing the possibility of deformations in the completed system. The box-molding system of the invention comprises simple elements which can be utilised for obtaining projections having different dimensions and which can be reutilized many times. The elements which make up the box mold of the present process enable the incorporating of the squaring beam 9 and the recuperation of the support bracket 8, which can be reutilized. The squaring beam 9, the molding slab 10 and the bearing structure 2 alone constitute the box mold which will contain the concrete jet. The process enables the mounting and dismounting operations of the box mold structural elements to be carried out in complete safety.

Claims: A box molding process for realizing projecting elements in reinforced concrete that project from a bearing structure such as a beam or a box like structure for making bridges and/or roofing elements, comprising, in order, the following phases: positioning of a support (3) provided with a pivot (4) on the bearing structure (2) and insertion of a tie-rod (5) on said bearing structure (2); positioning of a bracket (6) by resting thereof on said pivot (4) and constraining of said bracket (6) to said tie-rod (5), said bracket is provided with an attachment element, said attachment element being situated on an end of the bracket and engaging the tie-rod anchored to the bearing structure, such as to constrain the bracket to the bearing structure, said bracket being provided at the other end with a plurality of holes arranged in two parallel lines and specially distanced from one another, positional adjustment of said bracket (6) through exact height regulation of the bracket (6) by acting on said tie-rod (5); positioning of a support bracket (8) that is substantially L-shaped, one arm of the L being constrained to the bracket and projecting downwards, the other arm of the L projecting towards the bearing structure and forming a rest base and constraint thereof to said bracket (6) by means of inserting therein a pair of plugs (12) constraining the support bracket to the bracket at a predetermined distance corresponding to the dimensions of the projecting element to be constructed; positioning of a squaring beam (9) that is placed on the said rest base between the bracket (6) and the support bracket (8); positioning of a molding slab (10) between the squaring beam (9) and the bearing structure (2); casting of a liquid concrete into the mould constituted by the squaring beam, the moulding slab and the bearing structure; freeing of said support bracket (8) when the concrete has hardened by removal of a first plug (12a) from a hole (7) afforded in said bracket (6); external wise rotation of said support bracket (8); recuperation of said bracket (6) and said support bracket (8), while the squaring beam (9) and the molding slab (10) are incorporated in the finalized reinforced concrete projecting element. A process as in claim 1, characterised in that the second plug (12b) is inserted in a hole (7) arranged vertically and alignedly to said first plug (12a). A process as in claim 1, comprising a phase wherein reinforcements for the future slab and for the projection to be obtained are set in a correct position. A process as in claim 1, comprising a drying and setting phase of the liquid concrete. A process as in claim 1, characterized in that , after the molding slab laying phase there is a control and adjustment phase of projection length and height before the concrete is cast. A process according to claim 1 characterised by the fact that it comprises a phase concerning the making of a lateral kerb (11), the said phase involving the building of a framework which, on the outer side, is obtained using the squaring beam (9) while on the opposite side, is obtained by adding a formwork element the said lateral kerb realisation phase being followed by phase of cement casting. A molding system for realizing projecting elements in reinforced concrete that project from a bearing structure comprising: a support (3) adapted to be located on the bearing structure (2), said support (3) exhibiting a pivot (4), a tie-rod (5) adapted to be constrained to the bearing structure (2) at a prefixed distance, a bracket (6) adapted to be positioned restingly on said pivot, said bracket being provided at one end with an attachment element (5a) predisposed to be constrained to the tie-rod (5), at the other end with a plurality of holes (7) arranged in two parallel and specially distanced lines, a support bracket (8) engaged with the bracket (6), said support bracket being L-shaped, wherein a first arm of said L-shape is adapted to be constrained to the support bracket (8) by means of a pair of plugs (12) inserted in said holes (7), constraining thereby the support bracket (8) to the bracket (6) at a predetermined distance from the bearing structure (2), corresponding to the dimensions of the projecting elements to be constructed, a first plug (12a) serving to rotatably engage the support bracket and the second plug (12b) serving to block rotation thereof, while the other arm of said L-shape constitutes a rest base, a squaring beam (9) adapted to rest on the rest base, a moulding slab (10), extremities of which are adapted to rest respectively on the squaring beam (9) and on the bearing structure (2).

Inventors: CAPPI LEONARDO, CAPPI, LEONARDO
Applicants: RIVOLI SPA, RIVOLI S.P.A.
Application year: 1996
Main classification: E01D21
IPC codes: E01D21, E04G13