METHOD OF MANUFACTURING SYSTEM FLOORS

Abstract: Method for manufacturing system floors, comprising prefabricated floor-elements. One or more prestressed concrete beams (7), provided with reinforcing media, extending from its upper side, by positioning means (9, 10, 11) are mounted upside down in a shuttering (1, 2, 3, 4) with preferably steel plate side walls. Then the shuttering, in which a (steel) reinforce­ ment in the form of a mat has been introduced, is poured with concrete up to the required thickness. After vibrating and sufficiently hardening the floor element is removed from the shuttering.

Description: Method of manufacturing floor elements of system floors, comprising at least one prefabricated floor element and which floor element or floor elements are thereafter mounted at the work site, the method comprising the steps of providing a flat lying shuttering having a flat, smooth and seamless base and sidewalls defining a mould for said element; introducing a reinforcement in the form of a mat of constructional steel parallel to and spaced from said base; providing at least one prestressed concrete beam for each said floor element, said beam being either completely hardened or still hardening, being of a length smaller than the length of the floor element in order to obtain mounting edges at opposing sides of said element and having reinforcing means extending from its upper side; positioning said beam upside down at a distance from said base equal to or smaller than the desired thickness of the floor slab such that said reinforcing means extend into said mould; pouring concrete in the mould to obtain a layer of the required thickness; vibrating said concrete layer if required; sufficiently hardening out the floor element and removing it from the shuttering. Such a method is known from the French patent application FR-A-2 578 276. The mounting edges obtained by this method are not smooth, being instead of varying thickness and therefore necessitating very accurate positioning in mounting the elements. Moreover between the abutting sidewalls of two elements a relatively large gap is purposely provided which has to be filled up with concrete or cement afterwards. From the US-A 2 510 810 a method is known for casting sidings in a frame with an adjustable base therein with over-lapping side bars removably and adjustably positioned thereon for forming over-lapping edges of forms cast in the frame. The invention is characterized in mounting said sidewalls on the base such that said sidewalls extend vertically over substantially their entire height with respect to said base, said height being at least equal to the desired thickness of the floor slab providing smooth mounting edges by means of removable elements preferably of steel, said removable elements having a smooth underside and extending perpendicular to the longitudinal direction of said beam or beams along and against opposing sidewalls over the entire length thereof, said removable elements being spaced at a distance equal to the desired thickness of the floor slab at the mounting edges and being present during pouring and compaction of the floor slab. By the use of the smooth steel plate sidepieces, smooth floor-element sidewall-surfaces are obtained and thus good abutment between adjacently lying floor elements, which permits the floor be walked over directly after mounting of the elements on the working site. Moreover in this manner a smooth mounting edge is obtained which has a constant overall thickness and which, during mounting on horizontal concrete beams for example, ensures that the upper surfaces of the adjacent floor elements abut one another without gaps. Another characterizing feature of the invention consists of introducing positioning means into the end faces of the prestressed concrete beams, fitting a two-part clamping device on opposite sides to the shuttering outside the sidewalls, said clamping device having positioning means on its facing sides co-operating with the said positioning means in the end faces of the concrete beams to clamp the prestressed concrete beams in immovable positions during pouring and vibrating of the floor slab. Through the application of these measures, predetermined fixed positions of the prestressed concrete beams with respect to the shuttering are achieved and which positions do not change during compacting the poured concrete and through which adhesion of the floor slab concrete to the beams remains undisturbed. A shuttering for carrying out the method according to the invention, also known from the French patent application FR-A-2 578 276, comprises a flat, smooth and seamless base onto which upstanding sidewalls are arranged and of which at least one is removable, constituting the mould for pouring in the concrete for the floor slab. To this end according to the invention the shuttering is characterized in that the base is preferably a steel plate which may be provided on its underside with strengthening ribs and that the sidewalls are mounted on the base such that said sidewalls extend vertically over substantially their entire height with respect to said base, said height of the opposing sidewalls and if required of the connecting sidewall, at least at a position where a mounting edge of a floor element is to be formed, being at least equal to the desired thickness of the floor slab; the shuttering further comprising removable elements preferably of steel, said removable elements having a smooth underside, the width of which is at least equal to the width of the mounting edges, said element extending along and against opposing sidewalls over the entire length thereof and being arranged thereon at a distance equal to the desired thickness of the floor slab at the mounting edges from the base. It will be clear that the base can be of any smooth material on the condition that it is resistant to wet, freshly poured concrete although in practice a steel plate is preferred. The number of up-standing sidewalls depends on the form taken by the floor element. If it is triangular in form, then naturally three sidewalls are sufficient. At least one of these sidewalls is removable such that, after hardening out, the floor element can be easily removed from the mould through it. Should the sidewalls not come free when required to, then the edges of the floor element will be damaged so that even then another finishing operation must be carried out on the floor element when it is mounted in place. Naturally, if it is so required, all the sidewalls can be made removable. The fixing hereto can be by any currently used method, such as by bolting or welding and such like etc. for example. The prestressed concrete beams can be laid on the base of the shuttering with the interposition of distance-pieces there between after which the concrete layer for the floor is poured and then vibrated for compacting by a vibrating appliance. According to yet a further characterizing feature of the invention, for each prestressed concrete beam a two-part clamping device is fitted on opposite sides to the shuttering outside the sidewalls, which two parts are provided on the facing sides thereof with positioning means to co-operate with the positioning means of the prestressed concrete beams for positioning and clamping said beams. Through the application of these positioning means, the prestressed concrete beams are always maintained in the same position relative to the base of the shuttering which can then be vibrated as a whole without the prestressed concrete beams losing their mutually-correct positions. According to still a further characterizing feature of the shuttering according to the invention, the sidewalls extending in the longitudinal direction of the prestressed concrete beam or beams are provided with complementary sections running in the longitudinal direction and parallel to the base and at equal distances therefrom. The advantage of this arrangement is that the complimentary sections of the adjacent floor elements slide into one another and vertical movement relative to one another is prevented. The invention will be better understood with reference to the accompanying drawings in which Fig.1 illustrates the manner in which a shuttering is built up according to the invention, Fig.2 is a front view of the shuttering of Fig. 1, fitted with a clamping device, Fig.3 illustrates an end of the prestressed concrete beams provided with different positioning means, Fig.4 illustrates the shuttering with a removable steel plate element for use if required, Fig.5 illustrates a floor element the beams of which are free of the mounting edges and, Fig.6 illustrates a floor element with complementary sections along two sidewalls. Fig.1 shows a shuttering according to the invention, comprising a steel plate base to which strengthening ribs 2 are welded to the underside thereof, further strengthening ribs (not shown) are welded vertically with respect thereto so that the base 1 is rigid in all directions. Sidewalls 3 of angle-iron are fixed to the base 1. This fixing can be achieved in various manners by the use of bolts, clamps or by welding. The same is applicable to the sidewalls 4 which in this case are also made of angle-iron. If sidewalls 3 and 4 are welded then the floor element can only be removed in the vertical direction and its edges can easily be damaged. This can be avoided by making at least two adjacent sidewalls removable so that the floor element can first be removed from the other sidewalls before hoisting out. Fig.2 is a front view of the arrangement of Fig.1 without the sidewalls 4. It can be clearly seen how a clamping device comprising two parts 5 and 6 can clamp the prestressed concrete beam 7 in the desired position so that the whole of the shuttering can be vibrated without the position of the prestressed concrete beam 7 relative to the shuttering changing neither coming loose from the poured floor slab. If it is required to position the prestressed concrete beam 7 without the aid of the parts of the clamping device 5 and 6, then this can be done with supporting blocks of cement or concrete as shown by the dotted line 8. In this case, it is impossible to vibrate the shuttering as a whole and the use of a vibrating appliance is required here. When clamping by means of the clamping device 5 and 6, it is necessary to ensure that the prestressed concrete beam 7 cannot move with respect to this clamping device. To this end, both the prestressed concrete beam 7 and the clamping device 5 and 6 are provided with complementary positioning means. A trio of possible types of such positioning means are illustrated in Fig. 3. In Fig. 3a the positioning device is in the form of four pins 9 introduced into the end of the prestressed concrete beam 7 to co-operate with the complementary positioning means in the clamping device 5 and 6 which are in the form of four holes. Fig.3b shows positioning means in the form of recesses 10 of rectangular cross-section and into which a complementary extension of the clamping device 5 and 6 fits. It is self-evident that the positioning means for the prestressed concrete beam 7 and the clamping device 5 can be interchanged. Fig.3b shows a positioning means in the form of a groove 11 of rectangular cross-section and which for example may extend over a distance of ten centimeters in the longitudinal direction in the side of the prestressed concrete beam 7 and co-operates with a complementary strip of rectangular cross-section fixed to the clamping device 5 and 6. It will be clear that the invention is not limited to the foregoingly described embodiments but that numberless variations hereof are possible. The positioning means in the prestressed concrete beam 7 may also be used if required in combination with a hoisting-gear to lift the floor elements out of the shuttering and to turn them over after they have hardened out. Fig.4 shows how to obtain smooth mounting edges of uniform thick-ness. The sidewalls 4 are milled off to a height 'd' equal to the required thickness of the mounting edges and to which removable steel elements 12 in the form of angle-irons with smooth undersides are fixed. It is also possible to allow these removable steel elements 12 to extend over the sidewalls and, if the latter are removable, to weld the removable steel elements thereto. Fig.5 shows a floor element the lengths of the prestressed concrete beams 7 of which are equal to the length of the floor element minus the sum of the widths of the mounting edges 14. It will be clear that the floor elements shown here are upside down as they come out of the shuttering. Fig.6 shows a floor element of which the sidewalls extending in the longitudinal direction of the prestressed concrete beams 7 are provided with complementary sections 15 and 16 running in the longitudinal direction parallel to the upper surface and at equal distances therefrom. To this end on one of the sidewalls 4 of the shuttering a corresponding strip is arranged, the section of which is complementary to the section 16, whereas the other sidewall 4 is provided with a nut with a section complementary to the section 15. If two adjacent floor elements are pushed against one another, then these complementary sections slide into one another and remain fixed relative to one another when a load is imposed on the floor elements between the mounting edges. If the floor elements are to be insulated on the undersides, then the prestressed concrete beams may be poured into a shuttering provided with a lining of insulating material with a more or less porous surface. After hardening out of the concrete mass, the insulating material is bonded to it. After pouring the floor slab, the insulating material is applied to that part of the floor slab exposed clear of the prestressed concrete beams with the exception of the mounting edges thereof.

Claims: Method of manufacturing floor elements of system floors, comprising at least one prefabricated floor element and which floor element or floor elements are thereafter mounted at the work site, the method comprising the steps of providing a flat lying shuttering having a flat, smooth and seamless base (1) and sidewalls (3,4) defining a mould for said element; introducing a reinforcement in the form of a mat of constructional steel parallel to and spaced from said base; providing at least one prestressed concrete beam (7) for each said floor element, said beam being either completely hardened or still hardening, being of a length smaller than the length of the floor element in order to obtain mounting edges (14) at opposing sides of said element and having reinforcing means extending from its upper side; positioning said beam (7) upside down at a distance from said base (1) equal to or smaller than the desired thickness of the floor slab (13) such that said reinforcing means extend into said mould; pouring concrete in the mould to obtain a layer of the required thickness; vibrating said concrete layer if required; sufficiently hardening out the floor element and removing it from the shuttering characterized by mounting said sidewalls (3,4) on the base (1) such that said sidewalls extend vertically over substantially their entire height with respect to said base (1), said height being at least equal to the desired thickness (d) of the floor slab (13) providing smooth mounting edges (14) by means of removable elements (12) preferably of steel, said removable elements having a smooth underside and extending perpendicular to the longitudinal direction of said beam or beams (7) along and against opposing sidewalls (3) over the entire length thereof, said removable elements (12) being spaced at a distance (d) equal to the desired thickness of the floor slab (13) at the mounting edges (14) and being present during pouring and compaction of the floor slab. Method as claimed in claim 1, characterized in introducing positioning means (9,10,11) into the end faces of the prestressed concrete beams (7), fitting a two-part clamping device (5,6) on opposite sides of the shuttering (1,2,3,4) outside the sidewalls (3), said clamping device having positioning means on its facing sides co-operating with the said positioning means (3,0,11) in the end faces of the concrete beams (7) to clamp the prestressed concrete beams (7) in immovable positions during pouring and vibrating of the floor slab (13). Shuttering for carrying out the method as claimed in claim 1 or 2, comprising a flat, smooth and seamless base onto which upstanding sidewalls are arranged and of which at least one is removable, constituting the mould for pouring in the concrete for the floor slab, characterized in that the base (1) is preferably a steel plate which may be provided on its underside with strengthening ribs (2) and that the sidewalls (3,4) are mounted on the base (1) such that said sidewalls (3,4) extend vertically over substantially their entire height with respect to said base (1), said height of the opposing sidewalls (3) and if required of the connecting sidewall (4), at least at a position where a mounting edge (14) of a floor element is to be formed, being at least equal to the desired thickness (d) of the floor slab (13); the shuttering further comprising removable elements (12) preferably of steel, said removable elements (12) having a smooth underside, the width of which is at least equal to the width of the mounting edges (14), said elements (12) extending along and against opposing sidewalls (3) over the entire length thereof and being arranged thereon at a distance (d) equal to the desired thickness of the floor slab (13) at the mounting edges (14) from the base (1). Shuttering according to claim 3, characterized in that for each prestressed concrete beam (7) a two-part clamping device (5, 6) is fitted on opposite sides to the shuttering (1,2,3,4) outside the sidewalls (3), which two parts are provided on the facing sides thereof with positioning means to co-operate with the positioning means (9,10,11) of the prestressed concrete beams (7) for positioning and clamping said beams (7). Shuttering as claimed in any one of claims 3, or 4, characterized in that the sidewalls extending in the longitudinal direction of the prestressed concrete beam or beams (7) are provided with complementary sections (15,16) running in the longitudinal direction and parallel to the base (1) and at equal distances therefrom.

Inventors: OUDENALLEN'S BETONINDUSTRIE B.V.
Applicants: OUDENALLEN'S BETONINDUSTRIE B.V.
Application year: 1987
Main classification: E04B5
IPC codes: B28B19