SURFACE MOUNT SECURITY BARRIER

Abstract

A surface mount security barrier includes a non-metallic matrix supporting and substantially encapsulating metal ballast. The security barrier has a mass in excess of 6 tonnes and a ratio of metal ballast to non-metallic matrix in excess of 1.5:1 by mass. A method of manufacturing such a security barrier is also provided.

Claims

1. A unitary surface mount security barrier, the barrier comprising: a non-metallic matrix, comprising concrete, supporting and substantially encapsulating metallic ballast, wherein said security barrier has a mass in excess of 6 tonnes and a ratio of metallic ballast to non-metallic matrix in excess of 1.5:1 by mass.

2. The surface mount security barrier of claim 1 wherein the ratio of metallic ballast to non-metallic matrix in excess of 2:1 by mass.

3. (canceled)

4. The surface mount security barrier of claim 1 having a bottom face and a top face and wherein the metallic ballast comprises a first layer of one or more pieces of metallic ballast located between the bottom face and the top face.

5. The surface mount security barrier according to claim 4 wherein the metallic ballast comprises at least a second layer of one or more pieces of metallic ballast located above the first layer and between the bottom face and the top face.

6. The surface mount security barrier of claim 4 wherein the matrix extends between said pieces of metallic ballast isolating them from one another.

7. The surface mount security barrier according to claim 1 comprising one or more lifting points embedded therein, said lifting points comprising two or more box sections extending therethrough and opening on opposing surfaces thereof.

8. (canceled)

9. The surface mount security barrier of claim 1 wherein the metallic ballast comprises one or more of: steel; lead; one or more pieces of metallic ballast, each said piece comprising a single elongate section of metallic billet; one or more pieces of metallic ballast, each said piece comprising a plurality of elongate section of billet; and one or more pieces of metallic ballast, each said piece comprising a plurality of pieces of metal, especially metal balls or small pieces of scrap metal, bound together by a binder material.

10. The surface mount security barrier according to claim 4 wherein the mass of the metallic ballast is biased towards a bottom face of the security barrier and wherein the first layer of at least one piece of metallic ballast is located in a lower 50% of the height of the security barrier.

11. (canceled)

12. The surface mount security barrier according to claim 10 wherein the first layer of at least one piece of metallic ballast comprises in excess of 60% of the metallic ballast.

13. (canceled)

14. The surface mount security barrier according to claim 1 further comprising a rebar cage substantially embedded within the matrix below the surface of said security barrier and surrounding said ballast within said matrix.

15. (canceled)

16. The surface mount security barrier according to claim 1 having a mass in the range of 7.5 tonnes and 8.5 tonnes, optionally comprising at least 5.5 tonnes of ballast.

17. The surface mount security barrier according to claim 7 having a bench or seat attached to one or more sides thereof wherein said bench or seat is attached to said lifting point.

18. The surface mount security barrier according to claim 1 further comprising a plurality of metal feet extending from a bottom surface thereof.

19. The surface mount security barrier of claim 18, further comprising a rebar cage substantially embedded within the matrix below the surface of said security barrier and surrounding said ballast within said matrix wherein said metal feet are formed as part of the rebar cage.

20. A surface mount security barrier system comprising a surface mount security barrier according to claim 1 and an anti-skid plate beneath said surface mount security barrier and wherein the anti-skid plate has a plurality of metal feet extending downwardly therefrom, said anti-skid plate comprising a steel tray in which the surface mount security barrier is located.

21. (canceled)

22. The surface mount security barrier of claim 1 further comprising one or more fence post holes extending downwardly into a top surface thereof.

23. The surface mount security barrier of claim 1 further comprising one or more post footing extending downwardly into a top surface thereof, said post footing for receiving, in use a post.

24. A security fence comprising a plurality of surface mount security barriers according to claim 22, a fence post located in one or more fence post holes in each said surface mount security barrier, and: at least one fence panel attached to fence posts of said adjacent surface mount security barrier, or at least one openable gate attached to said fence posts of said adjacent surface mount security barrier.

25. A security fence comprising a plurality of surface mount security barriers according to claim 23, a spring steel security post located in the security post footing of adjacent surface mount security barriers and a further security barrier comprising either one or more flexible barrier or a rigid barrier extending between the security posts of said adjacent surface mount security barriers, and wherein said flexible or rigid barrier is either permanently attached to said security posts, or is releasable from said security posts to create an openable barrier.

26. A method of manufacturing a unitary security barrier comprising a non-metallic matrix supporting and substantially encapsulating metallic ballast, wherein said security barrier has a mass in excess of 6 tonnes and a ratio of metallic ballast to non-metallic matrix in excess of 1.5:1 by mass, the method comprising: placing a first piece of a rebar cage, comprising at least a lower face of said rebar cage, adjacent a lower surface of a mould; placing a first layer of at least one piece of metallic ballast above said lower face of the rebar cage; placing at least two lifting points within the mould; placing a second piece of a rebar cage within the mould, the second piece of the rebar cage comprising the remaining faces thereof; and pouring concrete into the mould to substantially encapsulate said metallic ballast and rebar cage.

27-31. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0031] FIG. 1 shows perspective view of a security barrier of the invention;

[0032] FIG. 2a shows a perspective view of the interior structure of a security barrier of an embodiment of the invention;

[0033] FIG. 2b shows a side view of the interior structure of the security barrier shown in FIG. 2a;

[0034] FIG. 2c shows an end view of the interior structure of the security barrier shown in FIG. 2a;

[0035] FIG. 3 shows a first part of a rebar cage used in the embodiment of the invention;

[0036] FIG. 4a shows a top part of a rebar cage used in the embodiment of the invention;

[0037] FIG. 4b shows a side part of a rebar cage used in the embodiment of the invention;

[0038] FIG. 5 shows a flow chart of the method of manufacturing a security barrier of the invention;

[0039] FIG. 6 shows the first part of the rebar cage of FIG. 4 together with a polyurethane foam sheet;

[0040] FIG. 7 shows a perspective view of a security barrier of the present invention with protruding anti-skid feet;

[0041] FIG. 8 shows an anti-skid plate for use with the invention;

[0042] FIG. 9 shows another embodiment of the security barrier of the invention;

[0043] FIG. 10 shows the security barrier of FIG. 9 with posts attached;

[0044] FIG. 11 shows a security fence according to the invention; and

[0045] FIG. 12 shows an alternative security fence according to the invention.

DETAILED DESCRIPTION

[0046] A security barrier, also known as a crash barrier, in accordance with an example embodiment of the present invention is described herein with reference to the accompanying FIGS. 1 to 4b.

[0047] With reference to FIG. 1, a security barrier 10 is shown. In the embodiment shown the security barrier 10 is substantially rectangular in shape, however it will be appreciated that the invention may have any suitable shape. In the example embodiment, the dimensions of the security barrier 10 are 2000 mm long, 1200 mm wide and 870 mm high, and it has a mass of approximately 8000 kg (+/10%). Two holes extend through the security barrier 10 from one face to the opposite face and are covered by cover plates 12. The holes form lifting points by which the security barrier 10 may be lifted. To move or lift the security barrier 10 the cover plates 12 are removed and lifting straps are passed through the holes therebehind from one side to the other. The ends of the lifting straps can then be attached to lifting equipment, for example a crane, to manoeuvre the security barrier 10. Once placed in its intended location the lifting points may be used as attachments to attach seats, benches or other furniture (e.g. planters or bicycle stands) to.

[0048] The security barrier 10 has an internal structure, as shown in FIGS. 2a to 2c, which is encased in non-metallic matrix, which in the example embodiment is cast concrete 14. By non-metallic matrix it will be understood that the matrix should be substantially non-metallic and that the addition of, for example, a small amount of metallic filler in the matrix will be deemed within the definition of non-metallic. In the example embodiment EN206-1:2000 C30 grade concrete was used (i.e. a concrete for which the minimum compressive strength of a 300 mm long, 150 mm diameter cylinder is 30 N/mm.sup.2) and the aggregate was 10 mm sized. Although it is shown as being completely rectangular in FIG. 1, it will be appreciated that the security barrier 10 could be cast with chamfered or radiused corners to reduce chipping thereof upon lifting or lowering of the security barriers.

[0049] Referring to FIGS. 2a to 4b the interior structure 16 of the example embodiment is shown.

[0050] The interior structure of the security barrier 10 comprises a first and second layer of pieces of metallic ballast which are in the form of steel blocks 18 located between a top face 20 and a bottom face 22 of the security barrier 10. In the embodiment shown the first layer comprises a first array of blocks and the second layer comprises a second array of blocks. The steel blocks 18 may comprise solid pieces of steel billet or may each comprise a plurality of strips of steel, placed adjacent one another or attached together. In the example embodiment the steel blocks 18 have a mass of 6000 kg (+/10%). This results in a ratio of metallic ballast to matrix of approximately 3:1 (excluding the rebar cage). It will be appreciated that a lower ration of ballast to matrix may be used from 1.5:1 upwards, for example the ration may be at least 1.75:1, at least 1.8:1, at least 2:1, or at least 2.25:1, or at least 2.5:1. It will be appreciated that increasing the ratio of metallic matrix to non-metallic aggregate increases the average density of the barrier, thereby enabling the same total mass to be achieved in a smaller space envelope, allowing for a more discreet and practical barrier without reducing its effectiveness. The pieces of metallic ballast forming the first layer have a greater mass than the pieces of metallic ballast forming the second layer. The first layer of steel blocks may account for in excess of 60% of the mass of the metallic ballast, optionally in excess of 70% or 80%. This biasing may be achieved by using different sizes of pieces of metallic ballast in each layer, a different number of pieces of metallic ballast in each layer, or different densities of metallic ballast (i.e. different metals or alloys) in each layer. By biasing the mass of the ballast, which has a greater density than the matrix, towards the bottom of the security barrier the stability of the barrier is increased under impact.

[0051] The steel blocks 18 are substantially surrounded by a rebar cage 24 that extends below, above and around the array of steel blocks 18 and substantially adjacent to, but beneath, the respective exterior surfaces of the cast concrete that surrounds the interior structure 16. Although shown as a rectangular array, the steel blocks 18 may alternatively be arranged in a linear array, or irregularly. It will also be appreciated that although shown as rectangular blocks, alternative shaped pieces of metallic ballast can be used as described in more detail below. The steel blocks 18 are arranged in spaced relationship to one another such than when encased in the cast concrete 14, the concrete passes around and between them in a continuous structure.

[0052] In the example embodiment a rebar cage 24 as shown in FIGS. 3, 4a, and 4b is used. The cage is made of 16 mm rebar and has overall dimensions of 1900 mm long, 1100 mm wide and 732 m high. The rebar 24 cage is made in three parts for convenience, although may be made in fewer or more parts. A first part 26 (FIG. 4a) comprises a lower face 28, and three side faces 30, 32, 34, leaving one side face and the top face open. A plurality of feet 36 extend downward from the lower face 28 to, during manufacture, allow the cast concrete 14 to fill a space below the rebar cage 24. The first piece 26 may be fabricated by any known method, for example it may be fabricated by welding, brazing or tying the rebar together.

[0053] A first layer of the steel blocks 18 is then located in the first part 26 of the rebar cage in a linear array, and a first two lengths of box section 38 are laid on top of them extending across the rebar cage 24 and protruding slightly from each side thereof.

[0054] The two lengths of box section 38 are dimensioned so that they are the same length as the width of the formed security barrier 10 and are located on top of the first layer of steel blocks 18 substantially perpendicular thereto. Optionally, a second two lengths of box section 44, which may be substantially identical to the first two lengths of box section 38, may be located below the lower face of the rebar cage. These second two lengths of box section 44, may form additional lifting points and/or additional fixing points for seats, benches or other furniture. The length of the first two lengths of box section 38 are such that they open onto opposing faces of the formed security barrier 10. A cover is placed over the end of each length of box section 38 to prevent concrete entering therein during the casting of the concrete matrix 14 around the ballast and rebar. The cover may be a bespoke cover or may for example simply be a temporary cover made of tape. After the security barrier 10 is cast the covers are removed and either disposed of or used in the fabrication of further security barriers. The second two lengths of box section 44 may be arranged in a similar manner.

[0055] A second layer of steel blocks 18 is then located above the first layer substantially parallel to the first layer and the remaining two faces being a top face 40 (FIG. 4a) and a side face 42 (FIG. 4b) of the rebar cage 24 are added and fixed in place for example by welding, brazing or tying. The remaining two faces 40, 42 may be added individually or may be formed and added as a single component.

[0056] The interior structure 16 is then encased in concrete as described above. The arrangement of the ballast as described above ensures that when the concrete is added it is able to extend between the pieces of ballast thereby substantially isolating them from each other. It also ensures that the concrete matrix is one continuous piece of concrete.

[0057] Referring to FIG. 5 the method of manufacture 100 of the invention is described.

[0058] At 102 the second two lengths of box section 44 are placed on the lower face of a substantially rectangular mould. The mould (not shown) comprises a bottom surface with four side pieces pivotally connected thereto such that they can be pivoted upwards to form a rectangular mould.

[0059] At 104 the first part 26 of the rebar cage 24 is placed adjacent a lower surface of the mould over the top of the second two lengths of box section 44.

[0060] At 106 a first linear array of steel bars 18 is placed on top of the first part of the rebar cage.

[0061] At 108 the first two lengths of box section 38 are placed above, optionally on top of, the first linear array of steel bars 18 substantially perpendicular thereto. Either prior to placement or after placement a cover is placed over the ends of at least each of the first two lengths of box section 38 and optionally over the ends of the second two lengths of box section 44.

[0062] At 110 a second linear array of steel bars 18 is placed on top of the first two lengths of box section 38, substantially parallel to the first linear array of steel bars 18.

[0063] At 112 the remaining faces of the rebar cage 24 not forming part of the first part 26 are added and fixed in place.

[0064] At 114 the mould is closed by raising the side pieces and securing them in place. It will be appreciated that this step is optional and may not be needed depending on the mould design.

[0065] At 116 concrete is added to the mould such that it fills all the spaces between the steel bars 18, the rebar and the lengths of box section 38, 44, and is left to solidify.

[0066] A security barrier 10 designed and manufactured according to the example embodiment was tested and passed the BSI IWA14.2013 collision test. In the test the security barrier 10 was placed on top of the test surface (flat concrete) without any attachment thereto or any foundations. A 7.5 tonne truck was collided with the security barrier 10 travelling at 64 kph (40 mph) and was stopped in its tracks. The security barrier 10 was impacted centrally on its two meter long face. It did not roll or spin and remained intact.

[0067] Referring now to FIGS. 6 and 7 a further embodiment of the security barrier 10a of the invention is shown. This embodiment is substantially the same as described above except in so far as the feet 36 project outwardly from the bottom face 22 of the security barrier 10a. The feet may project in the region of 1 to 10 mm, optionally in the region of 3 to 5 mm. In use, when placed on a hard surface, for example concrete or tarmacadam, due to the weight of the security barrier, the feed will, under impact, act as teeth and provide very high pressure contact points which, if the block moves as a result of an impact, will dig into the surface on which it is situated, further impeding the movement of the security barrier. On some very hard surfaces, for example granite, it may improve the performance if the feet are tapered towards their outer ends to reduce the surface area of contact between the feet and the surface on which it is resting, thereby increasing the pressure at each foot.

[0068] In order to manufacture the security barrier 10a the process described above in relation to FIG. 5 is substantially followed apart from, as shown in the dashed boxes of FIG. 5 step 102 above is replaced by step 102a and 102b. Instead of the box sections 44 being placed on the lower surface of the mould, first a sheet of polyurethane foam 46, for example a high-density polyurethane foam is placed on the lower surface of the mould so as to cover it. The box sections 44 are then placed on top of the polyurethane foam sheet 46 so that they are separated from the lower surface of the mould by the sheet. The method then continues to step 104 in which the first part of the rebar cage 26 is placed in the mould. In order for the feet 36 to project from the mould once the security barrier 10a is formed it is necessary for the feet 36 to project into the polyurethane sheet. This may be achieved in two ways. Firstly, the sheet 46 may be provided with a plurality of holes formed in it corresponding to the location of the feet 36. It will be appreciated that this will either need accurate geometric assembly of the first piece 26 of the rebar cage, or customised manufacture of the holes in the sheet to match the feet location of the first piece of the rear cage. Alternatively, to reduce the necessity for pre-making holes in the polyurethane sheet 46, the feet may be punched into the polyurethane sheet in situ in the mould. This could be achieved purely by the application of the metal ballast in steps 106 to 110 of the method applying sufficient pressure to push the feet into the polyurethane sheet 46, or alternatively the first piece of the rebar cage could be struck, for example with a mallet, above each foot 36 thereby driving it into the polyurethane sheet.

[0069] Once the security barrier 10a has been cast and has hardened, after it is removed from the mould the polyurethane foam sheet 46 is removed from the lower surface thereof. Rubber or plastic caps (not shown) can then optionally be fitted over the projecting metal feet 36. In use this allows the security barrier to be positioned and repositioned by lifting and moving, onto surfaces without the feet causing damage. If, however, in use the security barrier 10a is struck, e.g. by a vehicle, with sufficient force to move it the pressure on the feet 36 will result in the caps being broken or torn off allowing the metal feet 36 to dig into the surface and further impede movement of the block.

[0070] Although the manufacturing method described hereinabove relates to the use of a polyurethane sheet 46, it will be appreciated that any suitable sheet material could be used. For example, if a sheet with premade holes is to be used then the sheet material could be a sheet of wood, for example. If, on the other hand, the feet are punched into the material then any material that will allow penetration of point pressure applied to the feet 36 but will substantially not crush under the even loading of the concrete when added to the mould, may be used. In addition, a thin sheet, for example a plastic sheet, may be applied between the sheet material and the concrete to prevent adhesion of the concrete to the sheet material to facilitate easy removal.

[0071] Referring now to FIG. 8 a yet further embodiment is shown. In this embodiment, instead of the projecting feet described in relation to FIGS. 6 and 7, a separate anti-skid plate 48 may be provided. The antiskid plate 48 comprises a tray structure 50 and a plurality of feet 36a. The tray structure is welded from 10 mm mild steel and has overall dimensions to accept the security barrier 10 therein within the upstanding walls thereof. A plurality of holes are drilled in the steel plate and 20 mm steel feet 36a are passed through and welded flush with the upper surface thereof so that they project 10 mm from the lower surface of the tray structure 50. The manufactured security barrier is then lowered into the anti-skid plate and grout is applied around the edge to retain the barrier in the plate. Alternatively, or in addition, the security barrier may be retained in the anti-skid plate 48 by screws or bolts. As described above, rubber or plastic caps may be attached to the bottom of the feet 36a.

[0072] Referring to FIGS. 9 to 11 an embodiment of the security barrier 10 is shown which is provided with fence post holes 52 extending downwardly thereinto from the top surface 20 thereof. The holes 52 are substantially square in shape although it will be appreciated that other shaped holes, e.g. round or rectangular may also be used. The holes 52 are formed by attaching tubular pieces of steel to the rebar cage prior to the matrix being cast around it so that the tubes become embedded in the matrix and open at the top surface 20 of the case security barrier 10. In addition, a security post footing 54 as described in GB 2511273 is also embedded within the matrix of the security barrier 10 so that it opens at the top surface thereof. In use fence posts 57 are inserted into the holes 52 and support posts 60 are attached to the fence posts 57 by fence spacers 58. In this way a support for a fence may be provided that extends to the ground. Although shown in both sides of the security barrier 10, it will be appreciated that in use the fence posts 57 and support posts 60 may just be provided on one side of the security barrier 10. Where a security post footing 54 is provided in the security barrier it is fitted with spring steel security posts 64. The security posts 64 can act to increase the effective height of the security barrier 10, however for enhanced protection in some applications it may be appropriate to connect security posts 64 of adjacent security barriers 10 with steel cables 66 as described in WO 2015/033100.

[0073] FIG. 11 shows a security fence comprising adjacent security barriers 10 having a fence post 57 located in each said hole 52 and extending substantially vertically therefrom. Attached at one end to each fence post 57 is a pair of fence spacers 58. The fence spacers are each attached at their other end to a support post 60 to which a fence panel 68 is attached. By means of the support post 60 and the fence spacers 58 the fence panel 68 is attached to the fence posts 57 located in the holes 52 of security barrier. Although it will be appreciated that the fence panel 68 could be attached directly to the fence posts 57 the described arrangement enables the fence panels to be located forward of the security barriers 10 so that they do not interfere therewith. Additional longitudinal fence braces 62 are provided extending between the support posts 60 of adjacent concrete blocks. Although two security barriers are shown it will be appreciated that any number of the security barriers 10 may be used to form a continuous fence. The fence panel 68 may be attached by means of simple U-bolts 72 or other easily attachable and releasable connectors, for example zip ties.

[0074] This design enables a fence to quickly be erected on the security barriers 10 that can then provide a single, or double, pedestrian barrier as well as a vehicular barrier. Although described herein as supporting fence panels 68 it will be appreciated that the fence posts 57 or the support posts 60 ay be used to support other security enhancements, for example a fence panel may have therein or may be replaced with an openable gate to selectively allow, for example, pedestrian access past the security barrier. In addition to the fence posts, spring steel security posts 64 are provided in the embedded post footings 54 and a plurality of wires 66 as described in WO 2015/033100 are attached between the security posts 64 of adjacent security barriers, thereby further inhibiting vehicular passage, in particular potentially allowing for a greater spacing between the security barriers.

[0075] Referring to FIG. 12 a variation of the embodiment of FIG. 11 is shown. In this arrangement a central section of the fence panel is split in the middle and is pivotally attached to the support posts 60 at either side to form two parts 74, 76 of an openable gate in the fence. As shown in FIG. 11 spring steel security posts 64 are provided in the embedded security post footings 54 of the barrier islands 10 on either side of the gate and a barrier is formed therebetween. In this embodiment a solid barrier 78, pivotal about one end, is provided between the security posts 60. In this manner a security barrier is provided that prevents both vehicular and pedestrian access, but which can be selectively opened to allow passage of both pedestrians and vehicles therethrough hen access is required.

[0076] It will be appreciated that the embodiments described herein are given as examples of the invention and that modifications may be made which are within the scope of the invention which is defined by the claims. In one alternative embodiment the metallic ballast may be an alternative metal to steel, for example it may be any metal having a similar or greater density. The metallic ballast may be provided in an alternative form to steel bars. In one embodiment the metallic ballast may comprise small pieces of scrap metal (e.g. steel), for example small metal discs (or similar shape) that are produced as scrap from the punching of holes in sheet metal. The small pieces may be set in a binder to hold them together, for example cement or a resin binder. Alternatively, they may be placed in containers, e.g. sheet metal troughs. In another alternative arrangement the ballast may comprise irregular shaped pieces of metal. In another embodiment the ballast may comprise small pieces of metal, for example metal shot, metal discs, or the like, mixed with the concrete prior to casting the security barrier.

[0077] It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.