A FLOOR SLAB MEMBER AND A METHOD OF MANUFACTURING THE SAME

Abstract: A floor slab member (1) comprising an upper slab (3) and a lower slab (2) made of reinforced or non-reinforced concrete and which are interconnected by concrete coupling members (5) between which there are provided concreteless spaces formed by a solid or non-solid mould (6) made of relatively light material. The mould is provided with longitudinal sidewalls (8) for forming coupling members having the form of continuous longitudinal side edges (4) between upper and lower slab and having openings contiguous with wall portions substantially perpendicular to the plane of the floor slab member. At least some of said wall portions as well as the sidewalls have a height equal to that of the coupling members.

Description: Title: A floor slab member and a method of aanufacturing the same. This invention relates to a floor slab member consisting of an upper slab and a lower slab made of reinforced or non-reinforced concrete and interconnected by intermediate concrete coupling membe between which there are provided concreteless spaces formed by a mo as well as a method of manufacturing such a floor slab, member. For manuf cturing prefabricated floors, use is made of a num ber of systems. When a ground level floor is concerned, no flat underside wi be required in a number of cases. Use can then be made of the so- called composite floor system, wherein relatively small, somewhat bridge-shaped building elements sure laid on concrete T-bea on which assembly a floor mass is cast, or of the panelled floor system, wherein floor slab members of inverted, stretched U-shape installed side by side form the floor surface. In both systems, in- sulating material may be applied to the underside. In case a flat underside is required, the floor is to be com posed of solid prefabricated slabs, or preferably of channel slabs from the viewpoint of saving weight, which can be deemed to be com¬ posed of an upper and a lower slab interconnected at regular inter- vals by substantially vertical longitudinal walls, thus producing a slab with a multiple of hollow longitudinal channels. The under¬ sides of these members too, may be covered with insulating material. For manufacturing an upper-storey floor from prefabricated elements, practically only channel and/or solid slabs are suitable, since a flat underside is required practically always. Again, from the viewpoint of saving material, weight and handling, channel slabs are to be preferred. Such channel slabs are normally made by extrudi concrete through a nozzle, with the hollow channels being formed by means of sliding cores. This manufacturing method requires highly capital-intensive investments on account of the expensive, relativ ly complicated installations and the required labour-intensive main¬ tenance thereof. This manufacturing method also entails the formatio of relatively broad coupling members widening towards the upper and lower slab, at least coupling members that are more voluminous than is required constructively. A floor slab member of the above described type is known from French patent 1,533,735. The mould herein is composed of plurality of cross-vault-shaped, metal members, so that a slab member is obtai ed having a clarity with columnar discontinuities which extends in two directions. The mould elements are not only relatively heavy and expensive, but moreover require elaborate and time-consuming operati in placing and interconnecting them. These operations are rendered yet more difficult by the required reinforcing rods extending .from th lower slab through the coupling members into the upper slab, which rods are moreover positioned at an angle, and at least partly overla the mould elements to be placed subsequently. It is an object of the present invention to provide a novel type of floor slab member which is applicable for both ground level and upper-storey floors and which, as regards weight and cost of material and manufacture, are favourably distinguished from prior ar types of floor slab members. According to the invention, this is achieved by the provision of a floor slab member of the above type, characterized in that the mould comprises sidewalls extending longitudinally of the floor slab member for forming coupling members having the shape of continuous longitudinal side edges between upper and lower slab, and has openin contiguous with wall portions of the mould, said wall portions exten ing substantially perpendicular to the plane of the floor slab membe a number of which wall portions, like the sidewalls, having a height equal to that of the coupling members. These features make for a re¬ latively light floor slab member which is easy to handle, since it contains comparatively little concrete. The reason is that the mould during the casting and the hardening of the concrete provides the required supporting capacity, so that it can be constructed optimal- ly and as light as possible, in particular as regards the volume of the coupling members, so that no allowance has to be made for the O behaviour of the concrete during the manufacture and hardening of the floor slab member. Besides, the application of a reinforcement in the coupling members can be omitted, since the continuous longi¬ tudinal sidewalls are to be dimensioned in such a manner that any loads, in particular transverse forces, can be properly taken up an transmitted, which renders the manufacture of the floor slab member considerably simpler and less expensive. The coupling members defin by the openings in the mould are mainly adapted for taking up and transmitting any local point loads exerted e.g. by a cupboard leg o the Like. In particular, when in accordance with a preferred embodimen of the invention, the mould for the entire floor slab member compri a single member, this is easy to be transported, stored, handled an placed due to its one-piece condition. Moreover, however, no expen- sive and complicated apparatus are required. The mould can be manufactured inexpensively as a simple com¬ pression-moulded, injection-moulded or cast piece from a relatively light material e.g. when in accordance with a further embodiment of the invention, the mould is a solid foam-plastic body having openin for the coupling members, which also enhances the insulating propert of the floor slab member. However, the mould may also be made of a different material, such as plastic-coated cardboard or papier machέ in which case it is to be preferred that the mould comprises a hollow, open box-shaped body having ribs or ridges for surrounding the openings for the coupling members and for forming possible stiffening members. Naturally, it is also possible in such an embodi ment that the mould is made from a foam-plastic material by a mould¬ ing process, so that, relative to the solid embodiment, a substantia saving in tempex can be obtained, however entailing slightly higher manufacturing cost and changed insulating properties. In the case of a hollow, open box-shaped design of the mould an improved support during casting and hardening of the concrete can be obtained when, in accordance with still a further embodiment of the invention, the moulds are provided with cross-sidewalls, which also enhances a closure of the cavities adjacent the cross side edges of the floor slab member. A further improvement of the support during casting concrete can be obtained when in accordance with another embodiment of the invention, the sidewalls and wall portions of the mould comprise bent foot portions pointing away from the coup ling members. When according to a preferred embodiment of the invention, the angle between a sidewall or a wall portion of the mould and the slab plane thereof exceeds 90°, the mould can be easily removed from its manufacturing mould, while the possibility of nesting a pluralit of moulds is also advantageous during transport and storage of the moulds. A strong, actually continuous coupling member connection be¬ tween upper and lower slab, with preservation of the advantages of a one-piece mould, is obtained according to a further embodiment of the invention when the coupling members consist of longitudinally ex tending ribs having a length smaller than that of the floor slab mem ber and a height equal to that of the longitudinal side edges, and of connecting ribs extending between the longitudinal ribs, having a height about equal to half the height of the longitudinal side edg with the longitudinal ribs, viewed in longitudinal direction, being arranged so as not to link upwitheach other, and the end of a longi tudinal rib being connected by means of a connecting rib to the ends of two longitudinal ribs arranged so as not to link up with each other. As a result of these features, two connecting ribs halfway in height extend from each longitudinal rib, while each of the connect- ing ribs again meets another similar connecting rib extending from a adjoining longitudinal rib at a next, longitudinal rib, so that any forces can be " taken up and transmitted optimally. A relatively simple rib pattern can be obtained when in accordance with a further preferred embodiment of the invention the longitudinal ribs, viewed in longitudinal direction, are arranged in offset relationship relatively to each other in such a manner that a next longitudinal rib is positioned centrally between the precedin adjoining longitudinal ribs. With a view to obtaining a relatively simple die for manufacturing moulds, it is to be preferred according to a further embodiment of the invention that the connecting ribs extend transversely to the longitudinal ribs. A smoother connection between the successive, offset longitudinal ribs can be obtained when according to a still further embodiment of the invention pairs of connecting ribs link up in V-shaped relationship with the end of a longitudinal rib. In case the floor slab member is designed for forming a groun level floor, a sheet of foam plastic is preferably adhered to the underside of the lower slab. The advantage of such a construction is that when e.g. in the prior art floor slab members, an insulating layer thickness of 5 cm is required, resulting in a sheet 5 cm thick underneath the known floor slab member, now a slab 3 cm thick wil be sufficient by designing the mould with a wall thickness of 2 cm. The present invention also relates to a method of manufacturi such floor slab members. This cam be effected in a very simple and relatively inexpensive manner, also as regards the apparatus to be used, in that in accordance with the invention a layer of concrete having the thickness of the lower slab is poured on a box-shaped for having a floor area equal to that of the floor slab member to be manufactured, and the mould is positioned on the lower slab with the longitudinal side edges and the wall portions around the openings directed downwardly while, with or without the use of a spacer membe the side edge of the mould is placed at a distance corresponding to the thickness of the longitudinal side edge to be formed from the sidewall of the form, concrete is poured on said mould until the coupling members and the upper slab are formed, and , after hardening the form is removed. These features make it possible to dispense wit all kinds of expensive and maintenance-intensive apparatus, such as extrusion nozzles, sliding cores and slideways, so that it will be sufficient to use relatively simple and inexpensive concrete pouring apparatus and simple, uncomplicated forms. Also the manufacture of a floor slab member insulated at the underside, which in the prior art sliding apparatus may give substantial problems, remains possible in the same simple manner when in accordance with a further embodi¬ ment of the invention, a plate or layer of foam-plastic material covering the bottom surface of the form is placed therein before the lower slab is poured. r jmr Some embodiments of the floor slab member according to the in - vention and a method of manufacturing the same will now be described by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a cross-sectional view of a first embodiment, show¬ ing a plurality of column-shaped coupling members, taken on the line I-I of Fig. 2; Fig. 2 is a cross-sectional view taken on the line II-II of Fig. 1; Fig. 2A is a cross-sectional view similar to Fig. 2 with a modified mould; Fig. 3 is a cross-sectional view of a second embodiment taken on the line III-III of Fig. 4; Fig. 4 is a cross-sectional view taken on the line IV-IV of Fig. 3; Fig. 5 is a cross-sectional view taken on the line V-V of Fig 4; Fig. 6 is a perspective view of a part of the mould of the second embodiment; Fig. 7 is a cross-sectional view, similar to that of Figs. 2 and 4, and showing a third embodiment; Fig. 8 is a cross-sectional view of a fourth embodiment; and Fig. 9 is a cross-sectional view of a form with a partly manufactured floor slab member according to the invention. Figs. 1 and 2 show a floor slab member 1 composed of a lower slab 2 and an upper slab 3 interconnected by longitudinal side edges 4 and coupling members 5 in the form of columns of circular cross- section. The space between the concrete portions 2-5 is filled up with a mould 6 consisting of a solid block of a synthetic plastics material having openings for the coupling members 5 and which, in fact, defines the internal form of the floor slab members during their manufacture. The mould may also be formed as a flat sheet material 7 from which project on one side sidewall portions 8 and tube portions 9 over a height equal to the desired distance between lower and upper slab, while moreover between the sidewall and/or tube portions, ther may be provided reinforcing or stiffening ridges or ribs, so that floor slab member as shown in Fig. 2A is produced. The columns 5 a positioned in a rectangular lattice pattern, but this may also be a_ny other pattern as long as the vertical fixation between lower sl 1 and upper slab 2 is ensured. Naturally, also other cross-sectional forms than circular ar possible. The longitudinal side edges 4 have such a width that any transverse forces can be taken up and transmitted to further struct ral members in the desired manner. Figs. 3-6 illustrate a floor slab member 10, which just as t floor slab member 1, is fitted with a lower slab 11, an upper slab 12 and longitudinal side edges 13. In this second embodiment there are provided two types of coupling members in the form of longitudi ribs 14 having a height equal to that of the longitudinal side edge 13 and of cross ribs having approximately half the height of the longitudinal side edges 13, with the longitudinal ribs 14 linking u both with the lower slab 11 and with the upper slab 12, but the cro ribs 15 only with the upper slab 12. Since, moreover, the longitudi ribs 14 are offset longitudinally relative to one another, with the longitudinal ribs 14, as viewed in transverse direction, overlappin one another along a distance equal to the width of a cross rib 13, there is formed a cavity 16 comprising a plurality of compartments which are all in open communication with each other by means of passages between the longitudinal ribs 14 and underneath the cross ribs 15. The cavity 16 is bounded on the one end by the top of the lower slab 11 and on the other end by a mould 17 abutting against the bottom of the upper slab 11, the sidewalls of the longitudinal ribs 14, the side and lower walls of the cross ribs 15 and the in¬ side of the longitudinal side edges 13. A further wall portion of the mould 17 shuts off the transverse side edges. Fig. 6 is a perspective view of a part of the mould 17. with the continuous longitudinal slots 18 being adapted to form the longitudinal ribs 1 and the troughed cross slots 19 for forming the cross ribs 15. As shown in Fig. 6, the mould is a one-piece member, since all "blocks" are interconnected by the lower wall of the trough of the cross slots 19. Fig. 7 shows a floor slab member 20 representing a third em¬ bodiment, comprising a lower slab 21, an upper slab, not shown, longitudinal side edges 22, longitudinal ribs 23, connecting ribs 24 and a mould 25. The longitudinal ribs 23 have a height equal to that of the longitudinal side edges 22, while the height of the connect¬ ing ribs 24 is half this height, with the connecting ribs 24 linking up with the upper slab. The longitudinal connecting ribs pattern is such that two connecting ribs 24 extend in the form of a V from eac end of a longitudinal rib 23, each of said connecting ribs, at the end of a successive offset longitudinal rib 23, meeting in the form of a V a connecting rib 24 extending from a longitudinal rib juxta¬ posed to said longitudinal rib 24. In this manner, there is formed in the floor slab member 20 a cavity composed of a plurality of compaurtments which- axe all in open communication with each other by means of passages underneath the connecting ribs 24, which means that the mould 25 can be a one-piece member. Fig. 8 shows a floor slab member 30 adapted in particulau: to form a ground level floor. The construction of this member can be compaxed with that shown in Figs. 1 and 2 or Figs. 3-5, be it that mould 31 is made of insulating material and has a wall thickness laurger than that of the mould 7 or 17. Furthermore, a plate 33 of insulating material is attached to the bottom of the lower slab 32. The thickness of the total layer of insulating material can be deeme to be the sum of the wall thickness of the mould 31 and the thicknes of the layer of the plate 33. One advantage of the floor slab member according to the in¬ vention is its relatively light weight and hence relatively low material cost and its convenience and ease in handling. A further very important advantage is the simple maumer in which the floor sla member can be manufactured, notably without the use of expensive, complicated and maintenance-intensive apparatus. In elucidation of the above advantages, a method of manufact such a floor slab member will be discussed hereinafter, with referen to Fig. 9. The starting point for manufacturing a floor slab member according to the invention may be a box-shaped form 40, as diagramm ally shown in Fig. 9. A lower slab 41 is cast in said form 40, afte which mould 42 is positioned. The latter may or may not be done by meams of spacer members having a width of a longitudinal side edge to be formed. After placing the mould 42, which is effected immedia ly after the casting of the lower sla_b 41, concrete is again cast i the form 40 on amd along the mould 42 in a quantity corresponding with the volume of the upper slab, longitudinal side edges and coup ling members to be formed. Naturally, a reinforcement may be placed in position for each of the members to be formed prior to the casti thereof. In case a floor slab member 30 according to Fig. 8 is to b made, it is to be preferred to first install a layer of insulating material in form 40 before the lower slab 41 is cast. Casting concre on such sheet or layer immediately results in proper bonding betwee the sheet or layer and the lower slab. It is self-evident that many modifications and variants are possible within the scope of the present invention. For instance, the columns and ribs patterns shown in the Figures should be seen as examples only, which can be varied in mamy ways. Besides, the floor slab members may, if desired, be provided with cross side edges by a suitable design of the mould, while depending on the desired in- sulating properties, also the floor sla_b member shown in Figs. 3-6,7 or 8 can be made with a mould filling up the entire cavity, as shown in Figs. 1 and 2. It is also possible to use continuous channel- shaped slots in the mould for receiving continuous reinforcing wires which slots may extend either longitudinally or transversely. In the discussion of the manufacture of a floor slab member, reference is made to a box-shaped form. It is also possible for the lower slot to be cast continuously with the cast portion being ad¬ vanced in longitudinal direction. Subsequently, a mould can be place on this advancing portion, after which subsequent casting can take place, thus making up a production line. Depending on the type of concrete used it may be advantageous to provide the edges of the mould to be placed on the concrete cast for the lower slab with foot members in the form of thickenings, bent wall portions or the like. Finally, it is observed that, in the .above, reference is made throughout to the lower and the upper slabs of the floor slab member O This terminology has been chosen in connection with the manufacturin method, but does not impose any requirement on, or pronounce any oreference for, the way in which the floor slab member has to be placed when constructing a floor. Accordingly, the lower slab may well be the top of the floor formed. ***** E OM

Claims: C L A I M S 1. A floor slab member comprising am upper slab and a lower slab made of reinforced or non-reinforced concrete and interconnect by intermediate concrete coupling members between which there are provided concreteless spaces formed by a mould, chauracterized in th the mould comprises sidewalls extending longitudinally of the floor slab member for forming coupling members in the form of continuous longitudinal side edges between upper and lower slab, and has openin contiguous with wall portions of the mould, said wall portions bein substantially perpendicular to the plane of the floor slab member, at least some of said wall portions as well as the side walls havin a height equal to that of the coupling members. 2. A floor slab member according to claim 1, characterized in that the mould for the entire floor slab member consists of a one- piece member. 3. A floor sla_b member according to claims 1 or 2, character¬ ized in that the mould consists of a solid foam-plastic body having openings for the coupling members. 4. A floor slab member according to claim 1 or 2, character¬ ized in that the mould consists of a hollow, open box-shaped body having ridges or ribs for surrounding the openings for the coupling members and for forming any stiffening members. 5. A floor slab member according to claim 4, characterized in that the mould is made from a foam-plastic material by a moulding process. 6. A floor slab member according to claim 4 or 5, character¬ ized in that the moulds are fitted with cross-sidewalls. 7. A floor slab member according to claims 4, 5 or 6, chauract ized in that the sidewalls and wall portions of the mould comprise bent foot portions pointing away from the coupling members. 8. A floor slab member according to any one of the preceding claims, characterized in that the angle between a sidewall or a wall portion of the mould and the slab plane thereof exeeds 90°. 9. A floor slab member according to any one of the preceding claims, characterized in that the coupling members comprise longitu¬ dinally extending ribs having a length smaller than that of the floor slab member and a height equal to that of the longitudinal sid edges, and of connecting ribs extending between the longitudinal rib having a height about equal to half the height of the longitudinal side edges, while the longitudinal ribs, viewed in longitudinal dire tion, are arranged so as not to link up with each other, and the end of a longitudinal rib is connected through a connecting rib to the ends of two longitudinal ribs arranged so as not to link up with each other in longitudinal direction. 10. A floor slab member according to claim 9, characterized i that the longitudinal ribs, viewed in longitudinal direction, are of set relative to each other in such a manner that a next longitudinal rib is disposed centrally between the preceding- adjoining longitudin ribs. 11. A floor slab member according to claim 9 or 10, character ized in that the connecting ribs extend tramsversely to the longitu¬ dinal ribs. 12. A floor slab member according to claim 9 or 10, character ized in that pairs of connecting ribs link up in V-shaped relation¬ ship with the end of a longitudinal rib. 13. A floor slab member according to any one of the preceding claims, chauracterized in that a sheet of foam-plastic is adhered to the bottom of the lower slab. 14. A method of manufacturing a floor slab member according t any one of the preceding claims, characterized in that a layer of concrete having the thickness of the lower slab is poured on a box- shaped form having a floor area equal to that of the floor slab member to be manufactured, and the mould is placed on the lower sla with the longitudinal side edges and wall portions around the open- • ings directed downwardly, while, with or without the use of a spacer member, the side edge of the mould is placed at a distance correspon ing to the thickness of a longitudinal side edge to be formed from the sidewall of the form, concrete is poured on said mould until the coupling members and the upper slab are formed, amd, after hardening the form is removed. 15. A method according to claim 14, characterized in that a foam-plastic sheet or layer covering the bottom surface of the form is placed therein before the lower slab is poured. OMPI

Inventors: SPITSE ROELOF JAN, SPITSE, ROELOF, JAN
Applicants: ALBRO HOLDING, ALBRO HOLDING B.V.
Application year: 1984
Main classification: E04C2
IPC codes: E04B5