GB2108187A

GB2108187A - Concrete forming apparatus

Info

Publication number: GB2108187A
Application number: GB08131424A
Authority: GB
Inventors: Hans Holger Sydney Mygind; Ernest Henry Barrett
Original assignee: TILEMAN AND CO Ltd
Current assignee: TILEMAN AND CO Ltd
Priority date: 1981-10-19
Filing date: 1981-10-19
Publication date: 1983-05-11
Also published as: NZ202211A; IT8223774A0; GB2108187B; AU8945982A; AU561007B2; IT1153259B

Abstract

Apparatus for forming hollow upright concrete structures by the jump-forming technique is disclosed which is particularly suited to structures where significant changes in circumference are required, as for example, in hyperbolic cooling towers. The apparatus comprises a plurality of units each consisting of a line of inner shutter panels (1A) and a line of outer shutter panels (1B), individual panels having common dimensions and being releasably incorporated in their line such that the overall length of the line can be changed (to suit changes in structure circumference) by adding or removing panels. Resultant changes in radius are simply accommodated by adjusting a tie assembly (6) interconnecting bracing carried by each panel. The lines of panels are carried by support post assemblies (9) relative to which they are pivotable and the lines of panels and their support post assemblies are securable to the structure being formed by brackets. During concrete formation the brackets are in lowered positions relative to the post assemblies (9). Lifting of the units for forming further concrete is effected by releasing the brackets but not the panels from the structure, raising the brackets and re-securing them to the structure at raised positions relative to the post assemblies, releasing the panels but not the brackets from the structure, raising the post assemblies and hence the panels relative to the brackets, and re-securing the panels to the structure with the brackets again at their lowered positions relative to the post assemblies. <IMAGE>

Description

SPECIFICATION Concrete forming apparatus This invention relates to concrete forming apparatus, in particular to apparatus for forming concrete by the so-called jump-form technique. In this technique upright cylindrical, conical and hyperbolic concrete structures, for example chimneys, towers for supporting television aerials, bridge towers and cooling towers are formed by moving upwards two formworks disposed one within the other and between which the concrete to be formed is placed. The apparatus described hereinafter is especially suited to the construction of hyperbolic natural draught cooling towers. Apparatus for constructing such towers has to be able to accommodate, in safety, large variations in the radius of the tower, and in the slope of the tower wall. It is also desirable that use of heavy lifting equipment is minimised.

According to the present invention there is provided apparatus for forming hollow upright concrete structures by the jump-forming technique, the apparatus comprising a plurality of units each consisting of a line of inner shutter panels and a line of outer shutter panels, individuai panels in each line having common dimensions and being releasably incorporated in the line such that the overall length of the line can be changed by adding or removing panels; bracing carried by each panel being interconnected in the assembled line, by an adjustable tie assembly, such that the line of panels forms a rigid unit the radius of which can be set by adjusting the tie assembly; each line of panels being carried by support post assemblies via adjustment means permitting pivoting of the line of panels relative to the post assemblies; each line of panels and its post assemblies being releasably securable to the structure being formed with the inner and outer lines of panels in opposed relationship to receive therebetween concrete to be formed; the post assemblies being secured to the sturcture via brackets which during concrete formation are in lowered positions relative to the post assemblies; lifting of the units for forming further concrete being effected by releasing the brackets but not the panels from the structure, raising the brackets and resecuring them to the structure at raised positions relative to the post assemblies, releasing the panels but not the brackets from the structure, raising the post assemblies and hence the panels relative to the brackets, and re-securing the panels to the structure with the brackets again at their lowered positions relative to the post assemblies.In this apparatus the provision of shutter panels having common dimensions facilitates selection of the overall length of each unit, which is particularly advantageous where significant changes in circumference are required as is the case in the construction of hyperbolic cooling towers.

Such changes in circumference of course involve change in radius and in the present apparatus this is simply accomplished by operation of the adjustable tie assemblies. It is to be noted that the radius of each line can be set at an appropriate stage in the lifting procedure, as can the angle of inclination of the line of shutter panels which also is simply set by operation of the adjusting means via which the line of panels is carried by its post assemblies. Conveniently lifting is effected by jack means provided in the post assemblies and advantageously this jack means is arranged to operate in compression when lifting the relatively heavy line of panels.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a developed somewhat schematic side view, in the direction of arrow I in Fig.

2, of one unit of apparatus for forming in concrete hyperbolic cooling towers by the jump-form technique, Figure 2 is a sectional plan view of the unit of Fig. 1, taken on line ll-ll in Fig. 1, Figure 3 is a sectional end view taken on line Ill-Ill in Fig. 1.

Figure 4 is a side view in better detail and on a larger scale of part of a unit such as is shown only schematically in Figs. 1 to 3, Figure 5 is a plan view taken on Line IV-IV in Fig. 4, and Fig. 5A is an enlarged detail at A in Fig. 5.

Figure 6 is a sectional view taken on line VI-VI in Fig. 4, Figure 7 is a plan view of a part of the unit as shown in Fig. 5 but drawn to a larger scale, Figure 8 is a schematic perspective view of a detail of the unit, Figures 9 and 10 are sectional plan views on a larger scale taken, respectively, on line IX-IX and line X-X in Fig. 1, Figure 11 is a side view showing, in detail, a part of a modified form of construction as viewed in the direction of arrow 11 of Fig.

12, Figure 12 is a plan view from above of the detail of Fig. 11, and Figure 13 is a sectional view on line XIII XIII in Fig. 11.

The unit shown in the Figures is one of a sufficient number to extend all around the cooling tower being erected. Each unit consists of a line of inner shutter panels 1A and a line of outer shutter panels 1 B between which the concrete that is to be formed is placed.

Each shutter panel 1 A, 1 B consists of a steel sheet 2 stiffened by stiffeners 3 secured to its rear face. At the upper part of the sheet 2 the stiffeners 3 support a bracing framework 4 that extends rearwardly from the sheet 2 and that carries, remote from the sheet 2, a mount 5 at an outer junction of the bracing framework 4. The shutter panels 1A or 1 B of each line are locked with one another by a tie rod assembly 6 which is locked to the mounts 5.

In the form shown in detail in Figs. 4 to 7, the tie rod assembly 6 consist of an inner rod 6A which is disposed within a series of sleeves 6B. The rod 6A passed through a hole in each mount 5, whereas each sleeve 6B extends from one side or the other of each mount 5 to a connector sleeve 7 mid-way between adjacent mounts 5. At its mount 5 end each sleeve 6B is locked with the adjacent mount 5 by a slot and co-operating lug arrangement, whereas at their connector sleeve 7 ends alternate sleeves 6B are each a slide fit within the adjacent connector sleeve 7, the other sleeve 6B that cooperates with this connector sleeve being in screw-threaded engagement with the connector sleeve.In this way each panel 1 A or 1 B is locked to the immediately adjacent panels on either side of it, the rod assembly 6 and connector sleeves 7 forming, in effect, an adjustable tie and strut arrangement extending along the whole length of the unit.

In its configuration as illustrated in Figs. 1 and 2 each panel line consists of nineteen similar panels disposed in a central run of nine panels and two outer runs of five panels each. This configuration can, of course, be varied to suit the profile of any particular structure. Between the central run and each outer run is disposed a post assembly 9.

Referring also to Figs. 3 and 8 and 9, each of these assemblies 9 includes an upright rectangular sectioned hollow post 10 that carries a frame 11 at its upper end, this frame being disposed between the panels 1A or 1 B that are on each side of the post and supporting a steel sheet 2A that bridges the gap between the sheets 2 of these panels. Each frame 11 carries a mount corresponding to the mounts 5 already described so that the frames 11 can be locked to the tie rod assemblies 6.

Each frame 11 is connected to its associated post 10 by pivot members 1 2A extending from the post 10 and slidably engaged in guides 1 2B provided on the opposing inner faces of the frame 11. From the base of the frame 11 for about one half of its overall length each post 10 is reinforced by a pair of channel members 1 3 fast with the opposed sides of the post 10 that are at right angles to the faces of the sheets 2/2A.The portion of the post that is reinforced by the channel members 1 3 is slotted, along its face that is nearest the concrete to be formed, and receives a bracket 14 that consists of an elongated rectangular-sectioned hollow body 1 4A which is disposed inside the post 10, and upper and lower arms 1 4B, 1 4C that project from the upper and lower ends of the body 1 4A out of the slot in the post 10 in the drection towards the concrete to be formed.

The arms 14B, 1 4C terminate in angle mounting plates 14D. The bracket body 1 4A has apertures 14E in a row along its length that constitute a rack with which co-operates a pawl mechanism 1 5 carried by the post 10.

At its lower end the bracket body 1 4A has a lug 1 6 to which is connected the piston rod 1 7A that projects from one end of the cylinder 1 7B of an hydraulic piston and cylinder assembly 1 7. At its other end the cylinder 1 7B is connected to a pair of lugs 1 8 that are fast with the bottom ends of the post 10.

In use units are assembled so as to extend all around the substantial wall, or ring guide, that is conventionally provided atop the cooling tower columns of a cooling tower. To achieve this, each unit assembled as shown in Figs. 1 and 2 with its two post assemblies in place is made fast with the wall or girder by making the arms 1 4B of the post assembly brackets 1 4 fast with the wall or girder at tie bolts anchored in the wall or girder and passed through bolt holes in the mounting plates 1 4D of the brackets 14. As illustrated in Figs. 1 and 2, the bases of alternate panels 1 A, 1 B are also secured to the wall or girder by utilising tie bolts anchored in the wall or girder and which in this case are utilised to make fast clamps 1 9 with the bases of the alternate panels.In addition to being made fast at their bases with the wall or girder, as illustrated in Figs. 1 and 2 the alternate panels of one line that are so made fast are also made fast to their opposite numbers in the other line by tie bolts passed through holes in lugs 23 provided at the tops of these panels.

As illustrated in Figs. 4 to 8, clamps such as the clamps 1 9 are not used and instead alternate panels carry upright strongbacks 1 9A that are secured to the tie bolts (referenced 1 9B in these Figures), these strongbacks being slidable along the panel frames for location with the tie bolts. In place of the lugs 23, holes through alternate panels are utilised. Furthermore, as shown in Figs. 5 and 5A, adjacent frameworks 4 are secured to each other by tie bolts 24 that clamp webs of the framework together between disc springs 25, rubber sealing strips 26 with steel inserts 27 being sandwiched between the framework webs.

In all cases the desired radius for the unit is set by adjustment at the connector sleeves 7.

If, at this stage, it is required that the panels be inclined, this is achieved by operating adjuster bolts 20A and 20B at the top and bottom of the frames 11 to pivot the panels 1A or 1 B about the pivot members 12A. It will be appreciated, therefore, that the pivot members 12A/guides 1 2B and the adjuster bolts 20A, 20B consistute adjustment mechanism via which the panels are carried by the support post assemblies and which permits pivoting the line of panels relative to the post assemblies.

Access for carrying out the operations to make fast the post assemblies and the panels, and to set the angle of inclination of the lines of units, is from scaffolding 21 (Fig. 8) fitted to the units of appropriate locations, and (as illustrated in Figs. 1 and 2) from working platforms 22 carried by the posts 1 0.

Gaps between immediately adjacent units are bridged by plywood sheets as at 2B in Fig. 1.

It will be understood that reinforcement bars will be in position, and that concrete placed between the panels 1A and 1 B will be formed as a continuous ring on the wall or girder. After this concrete has been placed, jump-forming proceeds as follows: In side Shutter Panels 1. Mounting plates 1 4D of post assembly brackets 1 4 released from tie bolts (tie bolts themselves left in position).

2. Adjuster bolts 20A and 20B operated to move post frames 11 away from placed concrete (pivot members 1 2A slide in guides 12B) so that brackets 14 will clear concrete face during subsequent lift of these brackets.

3. Jacks constituted by piston and cylinder arrangements 1 7 extended to raise brackets 14 relative to remainder of post assemblies (bracket 14 lowered position shown for inside shutter panels in Fig. 3 and raised position shown for outside shutter panels.) 4. Adjuster bolts 20A and 20B operated to move post assembly brackets 1 4 towards the placed concrete to engage further tie bolts. Note here that as forming proceeds tie bolts left in the formed concrete become available for anchoring both the bottom and the top of each bracket.

5. Brackets 14 bolted tight against concrete face, any adjustment required in post alignment to suit slope of wall being effected at upper bracket arm 1 4B by inserting packing 28 (Fig. 3) between mounting plate 14D and concrete face.

6. Shutter panels 1 B released from tie bolts (tie bolts left in position as mentioned in 4 above).

7. Adjuster bolts 20A and 20B operated to move shutter panels runs clear of concrete face.

8. Jacks constituted by piston and cylinder arrangements 1 7 retracted to raise posts 9 and hence shutter panel runs (panel runs supported via rack and pawl arrangements 14E/15 during lifting).

9. At completion of lift adjuster bolts 20A, 20B operated to bring shutter panels into position for placing concrete.

10. Bases of alternate panels secured, by clamps 1 9 or strongbacks 19A, to tie bolts previously left in position.

11. Top radius of shutter runs set as necessary by adjusting tie rod assembly 6 at connector sleeves 7.

1 2. Reinforcement fixed in position.

Outside shutters Steps 1-11 above repeated.

1 3. Upper tie bolts fixed through holes in lugs 23 between opposing panels, or through holes in alternate opposing panels.

14. Concrete placed.

It is to be noted that push-pull props 29 (Fig. 8) are provided in the scaffolding 21 for levelling working platforms of the scaffolding as necessary.

As forming proceeds, to accommodate changes in radius the plywood panels 2B bridging the gaps between adjacent units are replaced as necessary and/or the end most panels of each unit are removed, or end panels are added. Placing of concrete can commence as soon as the inner and outer shutters of one unit are in position, suitable stop walls being inserted temporarily.

It is to be noted that the shutters of each unit have common dimensions which simpli fies assembling the unit, and that the panels once assembled are locked together in very rigid fashion and yet in a manner permitting large variations in radius by operation of the connector sleeves 7 of the tie assemblies 6.

The range through which the shutter runs can be pivoted by operation of the adjuster bolts 20A, 20B is + 30 to the vertical. This enables a change of batter of over 1, between successive 1.8 metres high lifts. The size of this possible change of batter is such that the apparatus is extremely versatile and is suitable for a large range of variations in cooling tower configuration.

It is also to be noted that the sequence of lifting operation is such that the lifting forces that have to be exerted by the post assembly jacks are relatively light when the jacks are working in compression (lifting post assem blies brackets) and relatively heavy when working in tension (lifting remainder of post assemblies and the shutter panels). Although particular suited for the construction of hyper bolic cooling towers, the apparatus described can, of course, be used for constructing other concrete structures such as chimneys and towers by the jump-form technique.

In Figs. 11 to 13 there is illustrated a modified form of tie rod assembly 1 06. In this form mounts 105 corresponding to the mounts 5 already described each carry an upright pin 105A. To each pin 1 05A there are pivotally anchored two oppositely directed bolts 125, 1 26 one of which is left-hand screw threaded and the other of which is right-hand screw threaded. These bolts are locked fast with the mount 105 by lock nuts 1 27 that co-operate via washers 1 28 with arcuate faces 1 29 of the mount 105 that are centered on the axis of the pin 1 05A of the mount. Each bolt 1 25 is secured, at its end remote from its mount 105, to one end of a connector tube 107, to the other end of which is connected the next bolt 1 26. To effect this connection the bolts 125, 1 26 are screw-threadly engaged with captive nuts 1 07A in the tube 107 and are locked in position by lock nuts 1 30. The span of the bolts 125/126 and the tube 107 between adjacent mounts 105 can be altered by adjustment at the tube 107 in turnbuckle fashion after releasing the lock nuts 1 27 and 130.

Claims

1. Apparatus for forming hollow concrete structures by the jump-forming technique, the apparatus comprising a plurality of units each consisting of a line of inner shutter panels and a line of outer shutter panels, individual panels in each line having common dimensions and being releasably incorporated in the line such that the overall length of the line can be changed by adding or removing panels; bracing carried by each panel being interconnected in the assembled line, by an adjustable tie assembly, such that the line of panels forms a rigid unit the radius of which can be set by adjusting the tie assembly; each line of panels being carried by support post assemblies via adjustment means permitting pivoting of the line of panels relative to the post assemblies; each line of panels and its post assemblies being releasably securable to the structure being formed with the inner and outer lines of panels in opposed relationship to receive therebetween concrete to be formed; the post assemblies being secured to the structure via brackets which during concrete formation are in lowered positions relative to the post assemblies; lifting of the units for forming further concrete being effected by releasing the brackets but not the panels from the structure, raising the brackets and resecuring them to the structure at raised positions relative to the post assemblies, releasing the panels but not the brackets from the structure, raising the post assemblies and hence the panels relative to the brackets, and re-securing the panels to the structure with the brackets again at their lowered positions relative to the post asemblies.

2. Apparatus as claimed in claim 1, wherein the bracing of each shutter panel carries a mount that is fast therewith, and wherein the adjustable tie assembly associated with each line of shutter panels comprises an inner rod passed through a hole in each mount of the line, a series of sleeves mounted on the inner rod one on each side of each mount, and collector sleeves also mounted on the inner rod, each sleeve of said series extending from its side of its associated mount to an associated one of the connector sleeves; each sleeve of said series being locked to its associated mount, alternate sleeves of said series being in sliding engagement with their associated connector sleeves, and the other sleeve of said series that is associated with each connector sleeve being in screw-threaded engagement with this connector sleeve, whereby rotation of the connector sleeve relative to the sleeves of said series engaged therewith moves these sleeves, and hence the mounts to which they are locked, towards or away from each other.

3. Apparatus as claimed in claim 1, wherein the bracing of each shutter panel carries a mount that is fast therewith, and wherein the adjustable tie assembly associated with each line of shutter panels comprises two oppositely directed bolts having screw-threads of opposite hand pivotally anchored to each mount, connector tubes with each of which two of the bolts having screw-threads of opposite hand are engaged by these screw threads of opposite hand, and means releasably locking each bolt to its mount and to its connector tube, rotation of each connector tube with the locking means released serving to move the mounts on each side thereof towards or away from each other.

4. Apparatus as claimed in claim 2 or 3, wherein each support post assembly includes an upright post that carries, via said adjustment means, a frame at its upper end, this frame being disposed between the panels that are on each side of the post and carrying a mount via which the frame is secured to the tie assembly, an associated one of said brackets being slidable with respect to this post and projecting therefrom, and the support post assembly further including a piston and cylinder arrangement operatively connected between the post and the bracket slidable with respect thereto, operation of the piston and cylinder arrangement serving to raise the bracket relative to the post when the bracket is free of the structure being formed, and to raise the post relative to the bracket when the bracket is secured to the structure.

5. Apparatus as claimed in claim 4, wherein each bracket is coupled with its associated post through a rack and panel arrangement.

6. Apparatus as claimed in claim 4 or 5, wherein said adjustment means comprises pivot members extending from said upright posts and slidably engaged in guides provided on said frames, and adjuster bolts at the tops and bottoms of the frames which are adjustable to bring about pivoting of the frames about the axes of the pivot members.

7. Apparatus for forming hollow upright concrete structures by the jump-forming technique, substantially as hereinbefore described with reference to Figs. 1 to 10, or Figs. 11, 1 2 and 13, of the accompanying drawings.