AU628313B2

AU628313B2 - Reinforced concrete construction

Info

Publication number: AU628313B2
Application number: AU28823/89A
Authority: AU
Inventors: Toby Griffith Thomas
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-02-18
Filing date: 1989-01-25
Publication date: 1992-09-17
Anticipated expiration: 2009-01-25
Also published as: AU2882389A; NZ228017A

Description

GRIFFITH HASSEL FRAZER, SYDNEY, AUSTRALIA 9020A/HM COMMON WEALTH OF AUSTRALIA PATENTS ACT 1952 Form COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: I. Cl: Application Number: Lodged:I Complete Specification-Lodged: Accepted: 66 Lapsed: 6 Published: Priority: Related Art: 6 66TO BE COMPLETED BY APPLICAN)T Name of Applicant: TOBY GRIFFITH THOMAS Address of Applicant: 7 Colliery Street, Stanford Merthyr, New South Wales 2327, Australia Actual Inventor: TOBY GRIFFITH THOMAS Address fi Service: GRIFFITH HACK CO.

.1 71 YORK STREET SYDNEY NSW 2000

AUSTRALIA

Complete Specification for the invention entitled: REINFORCED CONCRETE CONSTRUCTION The following statement is a full description of this invention, including the best method of performing it known to me:- 5268A/HM SOC~OZ23 2 0/ The present invention relates to the construction of reinforced concrete elements, and more particularly concerns suzh elements formed in a mould.

It is well-known to form reinforced concrete structures in a shaped mould, reinforcing steel being disposed ii the mould and vibration applied to compact the plastic concrete mixture before curing. One arrangement involves vibrating the whole mould, e.g. by mounting it on a vibrating table and another technique is to attach vibrating units to the mould at spaced positions and then to vibrate the mould.

Yet another technique is to use a fixed mould and to insert a vibrating probe on the end of a shaft; the vibrating probe is moved around, usually manually, within the mould after the concrete has been poured. These arrangements are .15 satisfactory for many products but it is considered there is *0 a need for more cost-effective, reliable and convenient techniques particularly where the products are other than large block-shaped products.

According to the present invention, there i's provided a method of forming reinforced concrete elements of panel-like form comprising: arranging a mould having a moulding cavity shaped II to define the required panel-like element with the cavity having its centra) plane extending substantially vertically and open at the top, inserting reinforcing steel into the cavity either during or after fabrication of the mould and either before or after the mould is arranged with the plane of the cavity extending substantially vertically, pouring concrete into the open top of the mould and vibrating the reinforcing steel so as to assist expulsion of air from the mould and comjaction of the concrete in the mould around the reinforcing steel, and after sufficient curing of tho concrete around the steel, removing the mould from around the concrete element so as to permit further use of the mould.

The method is especially significant and advantageous in the situation where it is desirable to mould 5739S -2ma r Li!IL simultaneously a multiplicity of reinforced double-side concrete panel-like elements.

For economic reasons it is very important that the method of moulding used is economical in the use of labour time, yet the method must be one which preserves accuracy but which uses a mould which is economic in terms of capital cost. Thus, an important embodiment of the invention is one in which the method includes assembling the mould with a rigid peripheral structure and a plurality of partition walls which are arranged vertically when the mould is in use and which define side faces of respective cavities in the mould, the reinforcing steel being inserted into each of the cavities. In this method, preferably, the concrete pouring step comprises distributing the poured concrete substantially evenly between the cavities as the mould is S gradually filled. By use of this method, the mould may be S ee of inexpensive form in which the partition walls, since they S are substantially evenly supported on each side by concrete, need only have little resistance to compression or bending.

Nevertheless, spacers may be incorporated if desired to space apart the partition walls, and these spacers may also be such as to ensure that the reinforcing steel, even under e. vibration, is always based a minimum desired distance from the edge of the panel-like element, e.g. a minimum of millimetres.

The invention is especially applicable for panel-like members for use in the fabrication of buildings such a garages and stables, where rectangular uniform panels are required. For example, the panels may be of the order of 4 metres long, 1 metre or more high, and 90 millimetres thick.

Preferably, the invention comprises using reinforcing steel in the form of a panel of mesh and a preferred embodiment is one in which galvanized steel studs are welded to the mesh and protrude out of the top of the cavity for connection to vibrating means. These galvanized studs may be useful in transportation and final installation of the formed panel.

Preferably the method comprises applying vibration to the reinforcing steel by the provision of a frame above the i :1 5739S -3 mould which is rigidly connected at spaced intervals along d the mould to the reinforcing steel, the frame being supported at intervals on the edges of the mould but with freedom for limited vertical motion; the frame is vibrated.

Typically and advantageously, vibration is applied by means of an electric motor with adjustable eccentric weights and a vibration rate of 2,800 cycles per minute with a vibration force of 1,000 kg. It has been found in a typical example that the vibration needs to be applied for a time of the order of 10 minutes, vibration occurring during and after pouring of the concrete into the mould.

Use of the invention can be most effective in permitting a low-cost mould to be formed. The mould preferably comprises a base, rigid exterior side panels formed from a framework with a facing panel, interior partition panels and rigid end wall elements which space the I panels apart by the desired amount; a multiplicity of tie rods extend acroiss the mould at intervals along the end walls and also at selected intermediate locations along the mould. When the concrete panel-like elements have been formed, the tie rods are unbolted and withdrawn. The rods could also extend through the panel-like element, and these tie rods can be withdrawn when the concrete has become solid but not fully cured.

'.25 In another aspect, the invention extends to a mould for use in the above method and wherein a multiplicity of panel-like cavities are provided for simultaneous moulding S' of a multiplicity of concrete elements; such a mould 9.9. comprises exterior side walls each having a reinforcing framework and a panel member for defining one side of a reinforced concrete element to be moulded, a plurality of partition panels for location in spaced parallel array between the side walls, wall elements for defining end walls for the mould and spacing the partition panels by the desired amount, a multiplicity of tie rods for connecting together the exterior side walls and for maintaining the desired dimensions of the mould, and a connector element for vibration transmitting connection to the reinforcing steel, 5739S 4 I the connector element being adapted to be vibrated to cause transmission of vibration to the reinforcing steel within the moulds during and/or after pouring of the concrete.

In yet another aspect, the invention consists in reinforced concrete panel-like elements formed in the above described mould or by the above described method in any of its forms.

For illustrative purposes only, an embodiment of the invention will now be described with reference to the accompanying drawings, of which: Figure 1 is a side elevation of a mould arranged for receiving concrete; Figure 2 is a plan view of the mould of figure 1; Figure 3 is a sectional side elevation through the mould of figure 1 but without the top vibrating frame in position and as taken along the lines III-III of figure 4; and Figure 4 is a plan view of the mould in the form shown in figure 3.

The mould 10 shown in the drawings has a base 11, end walls 12, side walls 13, divider panels 14, and a top vibrating frame 15 arranged to be connected to panels of reinforcing mesh 16 disposed within the respective mould cavities 17.

In figure 2, for clarity, the panels of reinforcing mesh 17 and the divider panels 14 have been omitted.

As best shown in figure 1, each side wall 13 comprises a peripheral framework of rolled steel section and vertical cross beams 18 with a formwork panel fixed to the interior of the framework for providing a smooth finish to the reinforced concrete panel. Each end wall 12 is formed from a series of timber spacer beams 19 between which the ends of the divider panels 14 fit and the mould assembly is secured together by a multiplicity of tie rods 20. Some nine (9) tie rods are used and shown in figure 1. Furthermore, the transverse dimension of the mould is fixed in the central region c the top of the mould by virtue of connecting elements 21 which link the top vibrating frame 15 to the top 5739S 5 frame elements of the side walls 13. Limited vertical freedom of motion is permitted. The mould further includes a central main cross bar 29 used to prevent the mould bowing outwardly in the centre region. The cross bar is simply fixed in position by having downwardly extending short rods at each end which are inserted in corresponding sockets fixed to the sidewalls 13. Furthermore, a set of 3 control bars 30 are provided spaced along the top region of the mould for the purpose of maintaining correct spacing of the respective divider panels 14. Each control bar unit comprises 2 parallel rods having respective downwardly extending pegs such that relative axial displacement of the rods in opposite directions brings the pegs into cuntact with the respective opposite sides of the divider panels thereby clamping the divider panels in the desired position. A push-pull arrangement is provided by providing an adjustment screw at one end, the adjustment screw being screw threadably engaged in a socket on one rod and engaging the other rod in order to push the rods axially.

The vibrating frame 15 as shown in figures 1 and 2, comprises a peripheral frame of longitudinal rolled steel section girders 22 and cross beams 23 of rectangular tubular section, with L section end beams 24. Further L section cross bars 15 are attached to the outermost pair of cross :25 beams 23. The cross bars 24 and 25 each have a set of seven vertical bores for receiving the threaded ends of galvanized connecting studs 26 which, as shown in figure 3 are welded to the top region of the reinforcing mesh 16 and are secured by nuts to the L-shaped cross bars 24 and A vibrating motor 27 is secured to the cross bars 23 in the central region as shown in Figures 1 and 2.

5739S-6

Claims

1. A method of forming reinforced concrete elements of panel-like form comprising: arranging a mould having a moulding cavity shaped to define the required panel-like element with the cavity having its central plane extending substantially vertically and open at the top, inserting reinforcing steel into the cavity either during or after fabrication of the mould and either before or after the mould is arranged with the pliine of the cavity extending substantially vertically, pouring concrete into the open top of the mould and vibrating the reinforcing steel sc as to assist S' expulsion of air from the mould and compaction of the concrete in the mould around the reinforcing steel, and 1 after sufficient curing of the concrete around the steel, removing the mould from around the concrete element so as to permit further use of the mould. S

2. A methoi as claimed in claim 1 and including assembling the mould with a rigid peripheral structure and a plurality of partition walls which are arranged vertically when the 425 mould is in use and which define side faces of respective cavities in the mould, the reinforcing steel being inserted into each of the cavities, whereby a multiplicity of separate panel-like elements are moulded, reinforcing steel being inserted into each of the cavities and concrete being poured into each of the cavities.

3. A method as claimed in claim 2 and wherein the concrete pouring step comprises distributing the pou.ed concrete substantially evenly between the cavities as the mould is gradually filled. 5739S 7 i.

4. A method as claimed in claim 2 or claim 3 and including using spacers to space apart the partition walls and to ensure that the reinforcing steel is always maintained a minimum selected distance from a wall of each cavity. A method as claimed in any one of the preceding claims wherein the method comprises using reinforcing steel in the form of a panel of mesh having galvanised steel studs welded to the panel of mesh for the or each cavity and positioning the steel mesh such that the studs protrude out of the top of the cavity for connection to vibrating means.

5

6. A method as claimed in any one of the preceding claims I e, and including rigidly connecting a vibrating frame at spaced intervals to the reinforcing steel, the frame being supported at intervals on the edges of the mould but with freedom for limited vertical motion and vibrating the frame in a -vertical direction to vibrate the reinforcing steel.

H 17. A method as claimed in any one of the preceding claims and comprising applying vibration by means of an electric motor with adjustable eccentric weights and a vibration rate :25 of 2,800 cycles per minute with a vibration force of 1,000 kg.

8. A method as claimed in any one of the preceding claims 3 and wherein vibration is applied during and after pouring of the concrete into the mould and vibration is maintained for the order of 10 minutes.

9. A method of forming reinforced concrete panel-like elements substantially as herein described with reference to the accompanying drawings. 5739S 8 A mould for use in the method of claim 2, the mould comprising exterior side walls each having a reinforcing framework and a panel member ior defining one side of a reinforced concrete element to be moulded, a plurality of partition panels for location in spaced parallel array between the side walls, wall elements for defining end walls for the mould and spacing the partition panels by the desired amount, a multiplicity of tie rods for connecting together the exterior side walls and for maintaining the desired dimensions of the mould, and a connector element for vibration transmitting connection to the reinforcing steel, the connector element being adapted to be vibrated to cause transmission of vibration to the reinforcing steel within the moulds during and/or after pouring of the concrete.

S i'

11. A mould substantially as herein described with reference to the accompanying drawings.

12. A reinforced concrete panel-like element formed in the method as claimed in any one of claims 1-9 or the mould as claimed in claim 10 or claim 11. Dated this 28th day of December 1988 TOBY GRIFFITH THOMAS By his Patent Attorney/ 9 GRIFFITH HACK CO. v" 5739S -9-