WO2007117133A1

WO2007117133A1 - Method for pouring sleepers and formwork used therefore

Info

Publication number: WO2007117133A1
Application number: PCT/NL2006/050251
Authority: WO
Inventors: Theo Winter
Original assignee: Koninklijke Bam Groep N.V.; Pfleiderer Infrastrukturtechnik Gmbh & Co. Kg
Priority date: 2005-10-07
Filing date: 2006-10-09
Publication date: 2007-10-18
Also published as: EP1941102A1; NL1030145C2; KR20080091755A; CN101326330A

Abstract

Method for pouring sleepers provided with projecting reinforcing bars into a ballast-free slab. The sleepers are placed together with the rails on a base and the rails are accurately positioned with hoisting jacks. Subsequently/simultaneously a formwork is fitted. A formwork of this type consists of a longitudinal formwork, in principle endless, and transverse formworks extending transversely thereon at regular intervals. The transverse formworks are constructed of formwork sections in order to be able to build such a transverse formwork in the presence of the sleepers and to be able to remove it again after the concrete has been poured. In particular the transverse formwork comprises the central transverse formwork section and end transverse formwork sections bordering thereon on both sides. The end transverse formwork sections are fitted from underneath the rails. Tensioning of the transverse formwork sections against one another takes place by means of a strip, extending over the entire length of the transverse formwork and fitted to the base, which is provided on the ends with tensioning means in order to press the longitudinal formworks against the transverse formworks. At a slightly higher level there are coupling rods to fix the transverse formwork sections in respect of one another.

Description

METHOD FOR POURING SLEEPERS AND FORMWORK USED

THEREFORE

The present invention relates to a method for pouring sleepers, provided with projecting reinforcing bars, to form a ballast-free slab, comprising the provision of a base, fitting said sleepers thereover this, providing longitudinal formworks, located opposite one another, and spaced transverse formworks, to enclose a series of sleepers, pouring concrete and removing said formworks.

Ballast is not used, especially in the case of tracks which are used for vehicles moving at high speed, but a number of sleepers are cast into a slab. A slab of this type preferably lies freely on the base and has a limited length so as to be able to absorb dilatation.

A structure of this type is produced after provision of the base, such as a concrete structure which bears the rails plus sleepers including the ballast-free slab. It is important to be able to produce such a structure relatively quickly. In other words, the aim is every day to provide tens and preferably hundreds of meters of rails/sleepers with the ballast-free slabs concerned. It is therefore important that the formwork used for this is easy to fit and to remove. This applies in particular to the transverse formwork to be fitted at regular intervals. Furthermore, it is desirable that the formwork can be reused. Such formwork should also be easy to adapt to local conditions, such as the presence of a difference in level between the left and the right rail on a bend, inclines and other structures deviating from a straight line.

The fitting of transverse formworks and removal thereof when rails and sleepers are already present constitutes a particular problem for quick and efficient working.

It is the aim of the present invention to provide an improved method with which in a simple way it is possible to fit and remove transverse formworks, so that large lengths of track and, more particularly the sleepers thereof, can be cast with a ballast-free slab every day.

This aim is achieved with a method described above in that the provision of said transverse formworks comprises arranging a transverse formwork section from each end of said sleepers in the longitudinal direction of said sleepers and placing said transverse formwork sections, which are fitted from the opposite side of said sleepeτs, against one another.

According to the present invention the transverse formwork is built on to transverse formwork sections, which transverse formwork sections can be moved below the rails (between two adjacent sleepers). Such transverse formwork sections are specified below as end transverse formwork sections.

It is possible to place such end transverse formwork sections against one another. However, it is also possible to fit one or more central transverse formwork sections between there. Such central transverse formwork sections can be positioned between the rails.

According to an advantageous embodiment of the invention the transverse formwork sections are tensioned against one another, the external pressure being applied by the longitudinal formwork sections. That is to say, longitudinal formworks located opposite one another are pressed towards one another while the transverse formwork sections are accommodated therebetween. Such application of tension can be realised by fitting a strip, extending over the entire transverse direction, to the base level, said strip being provided at one or both ends with tensioning elements which act on the longitudinal formworks or a profile acting on the longitudinal formworks.

According to a further advantageous embodiment of the invention there are coupling rods at a slightly higher level than the base. Such coupling rods make it possible to place the transverse formwork sections against one another at the top, thereby preventing concrete mortar being moved along them. Such coupling rods are designed such that they can be moved underneath the rails and can be hooked from one side underneath the rails into a transverse formwork section which is already present, whereupon a tension can be applied. Such a structure is once again easy to take apart and can in a particularly appropriate manner be made of steel, which means the structure concerned can be used many times. The longitudinal formwork preferably consists of longitudinal elements which can be coupled to one another and form a continuous longitudinal formwork.

The invention also relates to the above-described formwork used in the method. The invention will be explained below in more detail with reference to an illustrative embodiment depicted in the drawings. Therein:

Fig. 1 shows diagrammatically in perspective the placing of rails with sleepers on a base;

Fig. 2 shows very diagrammatically a formwork fitted round the structure of Fig. 1 ; Fig. 3 shows a section of the formwork according to Fig. 2; Fig. 4 shows the longitudinal formwork; Fig. 5 shows in cross-section a detail of the transverse formwork with a poured slab; Fig. 6 shows in end view a detail of the transverse formwork; Fig. 7 shows diagrammatically the removal of the transverse formwork; In Fig. 1 a base on to which a ballast-free slab, in which the sleepers of a rail structure are accommodated, is to be poured, is indicated by 1. This base 1 can be any adjustable base, such as a settlement-free slab.

The sleepers 2 are mounted in advance on comparatively short rails 6. These rails may have a length of 14 meters, for example. Reinforcing bars 3 extend from the sleepers 2. There are hoisting jacks 5, with which the position of the rails 6 can be accurately set. Further longitudinal reinforcement or transverse reinforcement is indicated by 4.

After the assembly consisting of rails 6 and sleepers 2 has been placed and the hoisting jacks 5 have been set, the idea is to anchor the sleepers 2 in a slab to be poured, in which the reinforcement 4 is also accommodated.

As can be seen from Fig. 2, for this there is provision of longitudinal formworks 7, 8 resting on the base 1. Each longitudinal formwork consists of a wall section 9 and a beam 10. This profile 10 can also serve as a runway for a concreting device or other processing device.

The longitudinal formworks can in principle be designed as continuous and for this purpose the appropriate longitudinal formwork sections are provided near the ends with coupling flanges, through which bolts or similar can be inserted (Fig. 4).

Because the slabs to be poured need to have a limited length because of dilatation, transverse formworks need to be fitted at regular intervals. Such a transverse formwork is indicated in its entirety by 11 in Fig. 2. In the illustrative embodiment shown here each transverse formwork consists of a central transverse formwork section 12 and end transverse formwork sections 13 abutting thereto (see Figs 2 and 5). It should be understood that it is possible to manage with only end transverse formwork sections 13.

Each transverse formwork section consists of two walls spaced apart. An example is shown in Fig. 6, the wall sections spaced apart being indicated by 24, between which on the one hand a groove 25 is limited and on the other hand on the underside a cavity 31. Transverse ribs and other reinforcements are of course present. When the transverse formwork sections 12, 13 are placed against one another, a continuous cavity 31 results on the underside, in which a tensioning strip 15 can be fitted (Fig. 3). The tensioning strip 15 is provided near each end with a sliding piece 17 which can be fixed on to the tensioning strip 15 with a clamping bolt 18. In practice the tensioning strip 15 will be placed first and its position can possibly be fixed in the base 1 by bolts 29 or other means. Then the transverse formworks 12 and 13 are placed on top of these. After this the longitudinal formworks 7 and 9 are placed over the tensioning strip 15. Subsequently, with bolt 19 of sliding piece 17 a pressure force can be exerted on the beam 10 of the longitudinal formwork concerned. If a pressure force is applied from opposite sides, the longitudinal formworks 7 and 8 will be moved towards one another while the transverse formwork sections 12, 13 are accommodated between them by clamping.

A clamping arm 20 acts on the top of the transverse formwork. This has an end flange 21. The dimension of the end flange is greater than the dimension of groove 25 and the dimension of arm 20 is smaller than that of the groove. In this way the clamping arm 20 can be fitted hooking behind such a groove, wherein central formwork section 12 is indicated by flange 21. On the other side there is a nut-like structure 22 and by the turning of a bolt 23 therein the longitudinal formwork 7 or 8 can be pulled towards the central transverse formwork section 13, on which the flange 21 of hoisting arm 20 acts.

If the rails with sleepers are placed first and then the pouring of concrete takes place, the logistical problem arises that it is difficult to fit and remove the transverse formwork. With the structure described above, it is possible in a simple way to avoid this problem. After all, according to the present invention the central transverse formwork section 12 is dimensioned such that it can be placed in between the rails 6 in the desired position above the tensioning strip 15 (Fig. 1). Both end transverse formwork sections can be fitted laterally from below, which means no conflict arises with the rails 6. The same applies to the removal of the transverse formwork after the concrete has been poured. This is shown diagrammatically in Fig. 7. Arrow 26 indicates the removal of the central transverse formwork section 12 and removal of the end transverse formwork sections is shown with the aid of arrows 27 and 28. The clamping arm is hooked in laterally underneath the rails 6 with the flange 21 acting on the central transverse formwork section 12.

With the structure shown here it is possible to fit a transverse formwork at any place desired and to remove it in a simple manner after the concrete has been poured and hardened. The method can be used both with rails placed flat and rails placed at an incline, as shown in Fig. 5, where the end result is shown after removal of the formwork. The thus obtained slab is indicated by 30. With the transverse formwork according to the invention it is possible to bridge differences in height between the two rails of approximately 180 mm and possibly more, without problems arising during fitting and/or removal of the transverse formwork sections. It is not necessary in this case to remove the rails from the sleepers.

Although the invention has been described above with reference to a preferred embodiment, variants which are within the concept of the invention described above will immediately occur to those skilled in the state of the art. The extent of protection of the present invention is not confined to the main claim but also extends to the subclaims, without combination with the independent claims of interest.

Claims

1. Method for pouring sleepers (2) provided with projecting reinforcing bars (3) to form a ballast-free slab, comprising the provision of a base (1), fitting said sleepers (2) thereover, providing longitudinal formworks (7, 8), located opposite one another, and spaced apart transverse formworks (11), to enclose a series of sleepers, pouring concrete and removing said formworks, characterised in that providing of said transverse formworks comprises arranging a transverse formwork section (13) from each end of said sleepers in the longitudinal direction of said sleepers and placing said transverse formwork sections, which are fitted from the opposite side of said sleepers, against one another .

2. Method according to claim 1 , wherein said placing of said transverse formwork sections comprises applying a tensioning force, pressing said transverse formwork sections against one another and against said longitudinal formwork sections from the opposite longitudinal formworks.

3. Method according to claim 2, wherein said tensioning force is applied near the underside of said formwork.

4. Method according to one of the preceding claims, wherein said transverse formwork sections are coupled to said longitudinal formwork sections near the top thereof.

5. Method according to one of the preceding claims, wherein said transverse formwork comprises a central transverse formwork section (12) and two end transverse formwork sections adjacent thereto.

6. Method according to claim 5, wherein said central transverse formwork section is substantially fitted and/or removed by vertical displacement (26) and said end transverse formworks (13) are substantially fitted and/or removed by a lateral displacement (27, 28).

7. Method according to one of the preceding claims, wherein said base (1) comprises a settlement-free slab.

8. Formwork to be provided to a base (1) for receiving therein a series of sleepers (2) arranged in succession and provided with projecting anchor bars (3), which formwork comprises two spaced longitudinal formworks (7, 8) and two transverse formworks (11), characterised in that each transverse formwork comprises two transverse formwork sections, wherein said longitudinal formwork comprises couplable longitudinal elements which form an endless longitudinal formwork.

9. Formwork according to claim 8, wherein said longitudinal formwork comprises connectable longitudinal elements, providing an endless longitudinal formwork.

10. Formwork according to claim 8 or 9, comprising a tensioner (15), said transverse formwork sections being provided on the underside with a cavity (31) for said tensioner, said tensioner acting on said longitudinal formworks to clampingly accommodate said transverse formwork therebetween.

11. Formwork according to one of claims 8-10, wherein said transverse formwork sections each comprise two spaced slabs (24, 25).

12. Formwork according to one of claims 8 to 11, comprising couplings (20) for connecting said transverse formwork sections and said longitudinal formwork sections at the top.

13. Formwork according to one of claims 8 to 12, comprising a central transverse formwork section (12) and end transverse sections (13) on each side thereof.

14. Formwork according to claims 12 and 13, wherein said coupling (20) comprises a coupling rod extending between said central transverse formwork section and said longitudinal formworks.