GB2402683A

GB2402683A - Shaping tie bars: reinforced concrete slab

Info

Publication number: GB2402683A
Application number: GB0412735A
Authority: GB
Inventors: Gerard Doyle
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-09
Filing date: 2004-06-08
Publication date: 2004-12-15
Anticipated expiration: 2024-06-08
Also published as: IE20040393A1; GB2402683B; IES20030432A2; GB0412735D0

Abstract

Tie bars 50 are laid on formers 20 on the bed of a shaping station, secured to formers 20, and pressed by press beam 35 acting between the formers to shape loops 4 into bars 50, the bars then being delivered to a moulding station, where a pair of them are placed in a mould also containing a reinforcing frame: concrete is cast into the mould to cover the reinforcing frame but leave loops 4 protruding, and the set slab 3 (Fig 1) removed. A clamp beam 38 (Fig 5) may hold the bars before press beam bends them; both these beams are driven by hydraulic rams 39, 36 respectively.

Description

At pre-cast reinforced concrete slaba This Invention relates to a process

and apparatus for manufacturing a pre-cast reinforced concrete slab, and in particular slabs used in the construction of floors in buildings.

According to the invention there is provided a process for manufacturing a precast reinforced concrete sub, comprising the steps: forming a plurality of shaped tie bars by delivering Qiongate steal bars to a shaping sWion, at the shaping station laying the steel bars side by side on a shaping bed, the bars extending across a plurality of space-apart formers which are seated on top of the bed, securing the bars on the formers, delivering prose beam on a carriago incrementally along the bed between a 2 0 number of bending positions, at each bending position positioning the press beam between an adjacent pair of formats and stopping the carriage, 2 5 extending the press beam downwardly to press the bars downwardly together betwoon the formats and then retracting the press beam, shaping A number of spaGod-apat loops in the bars In this manner for forming the shaped tie bars, delivering the tie bars to a moulding station, at the moulding station mounting a pair of the tie bars in a slab forming mould, locating the tie bars adjacent opposite sides of the mould, At: : .: age.. - 2 -

inserting a steel reinforcing frame into the mould with a top of each tie bar projecting above the reinforcing frame, pouring a quantity of liquid concrete into the mould, covering the steel reinforcing frame with the concrete and leaving an uppermost portion of each tie bar projecting upwardly from a top surface of the concrete in the mouid, setting the concrete In the mould to form the reinforced concrete slab, and removing the reinforced Concrete hub from the mould.

In a preferred embodiment of the invention the process includes clamping the bars at each bending position by extending a clamp beam which is mounted on the carriage to engage and clamp the bars against the bed before extending the press beam downwardly for shaping the bars.

In another embodiment the clamp beam Is extended downwardly for engagement with the bars within previously formed looped portions of the bars.

In a further embodiment Me process includes securing the bars on the farmers by laying a cross bar across the bare at each former and fastening the cross bar to the former for clamping the bars between the cross bar and the former.

In a preferred embodiment the farmers are cylindrical in shape, the fommers being 2 5 mounted on the bed in a parallel spaced-apart relationship.

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings, in which; Fig. 1 is a perspective view of a pre-cast reinforced concrete slab manufactured ace ordain to the prccess of the invention; Fig. 2 is an elevation view of a shaping station used in the process; 4 e À ce C À À À a e e Fig. 3 is an end elevational view of the shaping station; Fig. 4 is a detail perspective view showing portion of the shaping station; Fig. 5 is a schematic elovational view illustrating operation of the shaping station; and Fig. 6 is an elevational view of a shaped tie bar formed during the process at the shaping station.

Referring initially to Fig. 1 there is shown a pre-cast reinforced concrete slab manufactured according to the process Of the invention indicated genordly by the reference numeral 1. The slab 1 has a reinforced concrete body 2 of generally rectangular shape. It mill be noted that roughly midway along a top face 3 of the slab 1 at opposite sides of the slab 1 a number of spaced-apart steel loops 4 project upwardly above top face 3 of the slab 1. These are for the reception of and engagement with tie rods which exterd between loops 4 on adjacent slabs 1 which are laid side by side in a building to construct a floor prior to covering the slabs 1 with a further layer of concrete to provide a uniform boor surface.

A process for manufacturing the slab 1 will nov/ be described. Shaped tic bare 10 (Fig. 6) are formed by delivering elongate steel bars to a shaping station 12. The shaping station 12 has a ground engaging frame 13 formed by a pair of spaced-apart elongate l-beams 14 interconnected by a number of box section cross beams 15. A 2 5 shaping bed 16 is supported on the frame 13 and comprises a bed plate 17 mounted between upper flanges 18 of the l-beams 14. A number of spaced- apart cylindrical formers 20 are mounted spaced-apart on the bed plate 17 in a parallel relationship.

Locking bolts 22 project upwardly at each end of each former 20 for engagement by a complementary cross bar 23 which can be extended between the locking bolts 22 and secured thereto by lock nuts 24. Rails 25 extend along an outer edge of each upper flange 18 of the i-beams 14. A carriage 30 is moveable along the rails 25 between opposite ends of the shaping bed 16. Rollers 31 on the carriage 30 engage the rails 25 for rolling the carriage 30 along the shaping bed 16.

À ::e eve::: Be I: se. - À. are: - 4 - A press ram 34 is mounted on the carriage 30 and comprises a box section press beam 35 mounted by a pair of spaced-apart rams 36 on the carriage 30 above the shaping bed 16. The rams 36 are operable to raise and lower the press beam Mounted on the carriage 30 behind the press beam 35 is a clamp beam 38 which is also of box section and is secured on the carriage 30 by means of a pair of rams 39 which are operable to raise and lower the clamp beam 38 on the carriage 30. All the rams 36, 39 are connected to a hydraulic popover supply for operation of the rams 3&, 39.

To form the shaped tie bars 10 a number of elongate steel bars 50 are laid side by side on the shaping bed 16, lying across the formers 20 as shown in Figs. 4 and 5.

The bars an are secured to each former 20 by laying a croa6 bar 23 over the bars 50 in engagement with the locking bolts 22 and securing the cross bars 23 to each former 20 by means of the lock nuts 24. This prevents any vertical movement of the bars 50 but will allow longitudinal movement if required to accommodate bending as described later. The carriage 30 is advanced to position the press beam 35 between a first pair of formats 20 on the shaping bed 16 and the rams 36 operated to extend the press beam 35 downwardly thus pressing the bars 50 downwardly between the tormers No forming a loop in the bars 50. The press beam 35 is then retracted and 2 0 the carriage 30 is moved along the rails 25 to position the press beam 35 above the next pair of formats 20. Before lowering the press beam 36 Use camp beam 38 Is lowered by the rams 39 into the previously formed loop 51 to securely clamp the bars SO against the bed 17. Then the rams 36 are extended to move the press beam 5 downwardly to form the next loop 51 in the bars 50 as shown in fig. 5. The carriage 30 is moved incrementally along the bed 16 in this fashion forming a new loop 51 in the bars 50 between each pair of formers 20. When the carriage 30 reaches the end of the bed 16 it is returned to the start position and the shaped tie bars 10 with the loops 51 are then removed from the shaping station 12 and delivered to a moulding station.

At the moulding station a pair of the tie bars 10 are mounted in a slab forming Would, the tin bars 10 being located at opposite Sides of the mould. A stool reinforcing fro,mo is also inserted into the mould with a semi-circular loop 4 at a top of each tie bar 10 projecting above the reinforcing frame. A quantity of liquid concrete is poured into c: : À c::: ce: À e - 5 - the mould covering the steel reinforcing frarna but leaving an uppermost portion of each loop 4 of the tie bar 10 projecting upwardly from the top surface of the concrete in the would (thus leaving the exposed loops 4 shown In Fig. 1). The concrete is allowed to set in the mould to form the reinforced concrete slab 1 and then the reinforced concrete slab 1 is removed from the mould.

The invention is root landed to the emboeliments hereinbefore d-ascribed which may be vanad In both construction and detail within the scope of the appended claims. l

Claims

ce' c: c:. ::: te e' is: À. À À ee. eee: - 6 - CLANUS

1. A pnoess for manufacturing a precast reinforced concrete slab, comprising the steps: forming a plurality of shaped Ue bars by delivering elongate steel bars to a shaping station, laying the steel bars side by side on a shaping bed, the bars extending across a plural of spaceoapart forrners which are seated on top of the teed, securing the bars on the Corners, delivering a press beam on a carriage incrementally along Me bed between a number of bending positions, at each bending position positioning the press beam bebNeen an adjacent pair of formers and stopping the carriage, extending the press beam downwardly to,oress the bars downwardly between the fanners and then retracting the press beam, sleeping a number of spaced apart loops in the bars in this manner for horning the shaped tie bars, delivering the Ue bare to a moulding octagon, at the rnouldir station repouring a pair of the tie Is in a slab forming rruld, locating the tie bars adjacent opposite sides of the mould, inserting a steel reinforcers frame into the mould with a top of each tie bar projecting above the reinforcing frame, pounce a quantity of liquid concrete into the mould covering the steel :. :e..e.:e a.e - 7 reinforcing frame with the concrete and leaving an uppermost portion of each be bar projecting upwardly from a top surface of the concrete in the mould, setting the concrete in the rr ould to form the reinforced concrete slab, and removing the reinforced concrete slab from the mouid.

2. A process as claimed in claim 1 induding the step of clarnpins the bars at each bending position by emending a clamp beam which is mounted on the carriage to engage and damp the bars against the bed before extending the press beam downwardly tOf shaping the bars.

3. A process as dairned in claim 1 or claim 2 induding extending the clamp beam downwardly for engagement with the bans within previously tombed looped portions of the bars.

4. A process as claimed in any preceding claim induding securing the bars on the bombers by laying a Gross bar on the bars at each fonrner and fastening the cross bar to the Former for clamping the bars between the cross bar and the romper.

5. A process as claimed in any preceding claim wherein the formerly are cylindrical in shape, the fanners being mounted on the bed in a parallel spaced-apart relationship.

B. A process for manufacturing a pre cast reinforced concrete slab subsnffaltr as hereinbefore described with reference to the accompanying drawings.

7. A precast reinforced concrete slab whenever produced by the process as claimed in any preceding claim.

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