GB2536959A

GB2536959A - Construction method and structures built using such

Info

Publication number: GB2536959A
Application number: GB1505749.0A
Authority: GB
Inventors: Joseph Foster David
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-02
Filing date: 2015-04-02
Publication date: 2016-10-05
Also published as: GB201505749D0

Abstract

The method comprises constructing a load bearing structure 1 by constructing a lightweight intermediate structure having a hollow framework comprising an interconnected network of tubular components 2. The tubular components are filled with a fluid composition. The fluid composition hardens such that the previously hollow framework is structurally reinforced to transform the lightweight intermediate structure into the load bearing structure. The tubular components may be made from plastic such as acrylonitrile butadiene styrene (ABS). The fluid may be a fibreglass reinforced resin. The tubes may be single plastic tubular components or made from an interconnected network of smaller tubular components connected together to form pipe constructs, for example by having smaller pipes twisted together and secured around a larger pipe (5, Figure 4). Also claimed is a bridge made using the method.

Description

CONSTRUCTION METHOD AND STRUCTURES BUILT USING SUCH

Field of the Invention

The present invention relates to a construction method that is particularly suitable for the construction of bridges and other load bearing structures.

Background of the Invention

The construction of bridges can be a complex, time consuming and expensive process. The construction of bridges in particular is made more difficult due to the io limited access available to engineers and construction workers when constructing a bridge in situ across a river or other such expanse.

It is known, in the case of small scale construction projects, to construct a bridge in a first location and then transport the bridge -either in one piece or in sections -to the location where the bridge is then secured across the river or other such expanse.

This approach allows for much better access during the construction of the bridge, or the bridge sections, which in turn helps reduce cost and speed up the construction process. However this approach becomes less viable as the size, and thus weight, of the bridge increases and the transportation of the bridge becomes prohibitively difficult, if not impossible.

Summary of the Invention

The present invention provides a construction method that is particularly suitable for use in the construction of bridges at a location away from the bridge's final location (i.e. bridging a river or other such gap), because such bridges are light enough to be transported from the first location to the final location.

It is envisaged that the construction method of the present invention may have a range of applications across the whole construction sector. However, the inventor considers that the advantages of the construction method of the present invention are particularly beneficial in the construction of bridges.

According to a first aspect of the present invention there is provided a method of constructing a load bearing structure, said method comprising: constructing a lightweight intermediate structure having a hollow framework comprising an interconnected network of tubular components; filling the interconnected network of tubular components with a fluid composition; and hardening the fluid composition such that the previously hollow framework is structurally reinforced to transform the lightweight intermediate structure into the load bearing structure.

so It is envisaged that constructing the load bearing structure in two stages, wherein the first stage produces a lightweight intermediate structure (i.e. the hollow framework), makes it possible to build larger structures away from the final location of the structure -i.e. the structure does not need to be made in situ.

In view of this the method may preferably further comprise constructing the is intermediate structure in a first location; and transporting the intermediate structure from the first location to a second location and securing the intermediate structure in place.

As already mentioned, the general construction method of the present invention is considered particularly suitable, and thus is preferable for, the construction of 20 bridges.

It is envisioned that the interconnected network of tubular components, which is eventually filled with the hardenable composition, comprises the structural components that run from one end of the intermediate/load bearing structure to the other.

These structural components, hereinafter referred to as longerons, would have additional structural components secured to them. It is envisaged that such additional components, which are oriented in in a substantially more vertical direction (i.e. from the top of the structure to the bottom), may also form part of the interconnected network of tubular components. However this is not considered essential because it is envisioned that the main structural strength of the final load bearing structure will be provided by the longerons (and their interaction with the bridge foundations).

In order to achieve the lightweight intermediate structure the tubular components from which the hollow framework is constructed are preferably formed from suitable plastic materials, such as acrylonitrile butadiene styrene (ABS).

By constructing the hollow framework from plastic materials rather than the typically used metals (e.g. steel) the overall weight of the intermediate structure is reduced, thereby making transport of larger structures possible. Indeed it is envisioned that the lightweight construction of the intermediate structure may make it possible to transport the intermediate structure by air.

Examples of air transportation means include: heavy lifting helicopters; teams of smaller polycopters (which may be remotely controlled, i.e. drones); and light than air methods, such as hot air balloons.

Preferably the intermediate structure is constructed such that it is capable of retaining the shape of the structure until the shape has been reinforced by the hardening of the fluid composition within the interconnected network of tubular components. Further preferably the intermediate structure is self-supporting.

The intermediate structure may be provided with temporary support means to help retain it shape until the shape has been reinforced by the hardening of the fluid composition within the interconnected network of tubular components.

One example of a temporary support means may take the form of a compressed gas pumped into the interconnected network at the construction location before the structure is moved. In this way the hollow structure, and thus the intermediate structure, can be given an element of rigidity without substantially increasing the overall weight of the lightweight intermediate structure.

It is also envisaged that a portion of the intermediate structure might be formed from non-hollow structural components. In order to maintain the lightweight character of the intermediate structure, the non-hollow structural components may preferably be formed from carbon fibre. Such non-hollow structural components help to retain the shape of the hollow framework until such time as the fluid composition has been hardened within the interconnected network.

In order to facilitate the filling of the hollow framework with the fluid composition the interconnected network may preferably be provided with at least one inlet valve assembly and at least one outlet valve assembly.

Preferably the method further comprises pumping the fluid composition into the interconnected network via said at least one inlet valve assembly. Additionally or alternatively the method further comprises applying a vacuum to the at least one outlet valve assembly to draw the fluid composition (and any trapped gases/air) so through the interconnected network and out of the outlet valve assembly.

At its most basic the hollow framework may be constructed from an interconnected network of single tubular components made from, for example, plastic pipes (e.g. ABS pipes).

However it is envisioned that the structural strength of the network may be further is enhanced by combining multiple smaller tubular components together to form pipe constructs.

Further preferably the smaller pipes may be secured around the outer circumference of a larger hollow pipe. Alternatively or additionally the smaller pipes may be twisted together (i.e. in a similar way to the way ropes are formed from multiple constituent 20 strands).

In such arrangements, multiple inlet and outlet valves may preferably be provided to ensure that all of the multiple tubular components are filled with the fluid composition and no dead spaces are formed.

Preferably the fluid composition used to fill the hollow interconnected network may take the form of fibreglass resin. Fibreglass resin is considered particularly suitable by the inventor because to can be produced in a fluid form that can then be pumped into the interconnecting network of the hollow framework.

In addition, once the resin has been allowed to harden within the hollow framework it will provide a structural strength that can be ten times stronger than steel.

Brief Description of the Drawings

A preferred embodiment of the present invention will now be described with reference to the drawings, wherein: Figure 1 shows a diagram of a bridge constructed in accordance with the method of the present invention; Figure 2 shows a cross-sectional view of a tubular component used in the construction method of the present invention; Figure 3 shows a cross-sectional view of an alternative tubular component used in the construction method of the present invention; Figure 4 shows a cross-sectional view of a further alternative tubular component used in the construction method of the present invention; and Figure 5 shows a diagram of an alternative bridge constructed in accordance with the method of the present invention.

Detailed Description of a Preferred Embodiment of the Present Invention The construction method of the present invention essentially involves two main stages.

The first stage is the construction of a lightweight intermediate structure that comprises hollow framework formed from an interconnected network of tubular 20 components.

Although the lightweight intermediate structure has substantially the same shape as the final load bearing structure that is to be constructed in accordance with the present invention, the intermediate structure lacks the load bearing strength of said final load bearing structure.

Instead the intermediate structure's main advantage is that, due to the use of the hollow components made from lightweight materials (i.e. plastic), it is much more lightweight than a conventional structure formed from the structurally strong materials (i.e. metals such as steel) normally used in the construction of load bearing structures, such as bridges.

This substantial weight reduction greatly improves the transportability of the intermediate structure, and in doing so opens up the possibility of constructing the structure off-site (i.e. not in situ). The advantages of which have already been mentioned.

Once the intermediate structure is positioned in its final location the second main stage of the present invention can be carried out. It is envisaged that the intermediate structure can be secured in position (i.e. across a river or other such so expanse) by using foundations from concrete and steel. Such conventional foundations are considered suitable to provide the required structural tension to the load bearing structure of the present invention, as is the case with conventionally constructed bridges.

In the second stage a fluid composition of a hardenable material (such as fibreglass is resin) can be pumped, or otherwise introduced, into the interconnected network of tubular components that makes up the hollow framework of the lightweight intermediate structure.

Once the tubular components have been filled with the fluid composition the composition is allowed to harden. It is envisaged that, depending upon the type of fluid composition used, some compositions may be allowed to harden naturally overtime, whilst others may require further treatment (e.g. heat treatment or UV treatment).

It is envisaged that as the fluid composition hardens within the tubular components of the hollow framework the intermediate structure is reinforced and given greater structural strength; thus transforming it into the final load bearing structure. Once the fluid composition has completely hardened the transformation from the intermediate structure to the final load bearing structure is complete. In the case of fibreglass resin it is appreciated that upon hardening such resin adopts a structural strength that is ten times stronger the steel.

Turning now to Figure 1, which shows a diagrammatic view of a bridge structure 1 constructed in accordance with construction method of the present invention. The bridge structure 1 comprises a hollow framework 2 formed from an interconnected network of tubular components 2'.

The interconnected network of tubular components 2' is arranged in a structurally supportive form, the exact arrangement of which would be determined by a structural engineer to meet the required specification of the final load bearing structure (i.e. bridge 1).

In the example shown it will be seen that the both the longerons 2a and the supporting cross-pieces 2b form part of the interconnected network of tubular components 2'. However, as already explained, it is envisioned that sufficient structural strength can be achieved by including only longerons 2a in the interconnected network.

A simplified view of a bridge 10 constructed with the simplified structural arrangement (i.e. the interconnected network only comprises the longerons 2a) is shown in Figure 5 with the cross pieces not shown.

The hollow framework 2, which forms an important part of the transportable lightweight intermediate structure, is provided with at least one inlet 3 and at least one outlet 4. The inlet 3 and the outlet are in fluid communication with the interconnected network of tubular components 2'.

Once the lightweight intermediate structure produced by the first stage of method of the present invention has been secured in position at the final location, which in the case of the bridge 1 would be across a river or other such expanse, the second stage of method of the present invention can begin.

In the second stage a source of the hardenable fluid composition is connected up to the inlet 3 by some form of pumping means (not shown). Advantageously a vacuum pump may be connected up to the outlet 4 to further assist the passage of the fluid composition through the interconnected network of tubular components.

It is envisaged that tubular components 2' used to construct the hollow framework may advantageously be transparent or at least translucent. In this way it is possible to monitor the progress of the fluid composition as it travels through the interconnected network of tubular components 2'. This ensures that no 'dead zones' are allowed to form within the network during stage two.

Once the interconnected network of tubular components 2' has been completely filled with the fluid composition it can be left to harden. It is envisaged that in some embodiments of the present invention the fluid composition used may require additional treatment to trigger the hardening of the fluid composition.

Once the fluid composition has hardened within the network of tubular components 2' the transformation of the lightweight intermediate structure to the final load bearing structure (e.g. bridge 1) is complete.

io it is envisaged that from this point onwards more conventional construction methods may be used to complete the construction of the bridge 1 (i.e. laying of road surface and utilities, etc..).

In one embodiment (see Fig. 2) of the construction method of the present invention the tubular components 2' might be provided in the form of a single pipe 5, whereby is the fluid composition is received within the interior 6 thereof.

In another embodiment (see Fig. 3) of the construction method of the present invention the tubular components 2' are provided not in the form of single pipe but rather in the form of construct 7 of multiple smaller pipes 7' that have been fixed (e.g. bonded) together. The interior 8 of each smaller pipe 7' receives the fluid composition as it is pumped into the hollow framework.

Although not shown, it is envisaged that the multiple pipes 7' may also be twisted together -very much in way that rope is formed -to form a stronger tubular component 2'. Indeed it is envisaged that even smaller pipes could be twisted together to form constructs that can then be twisted together with other similar constructs to form a super-construct, with further enhanced structural strength.

In a further embodiment of the construction method of the present invention the hollow framework can be constructed using a combination of tubular components described above. It is even envisaged that a tubular component may be constructed by securing a plurality of smaller pipes 7' around the larger pipe 5, (see Fig. 4).

The embodiment of the pipe construct 9, shown in Figure 4, is considered to be particularly useful in retaining the shape of the intermediate structure during its transportation.

Specifically, it is envisioned that one or more of the outer pipes 7' can be filled with the hardenable composition prior to the transportation stage. In this way the hollow framework of the intermediate structure is provided with a level of reinforced rigidity.

The structural strength of the intermediate structure can further be reinforced by filling the central pipe 5 with a pressurised gas prior to transportation.

Claims

Claims 1. A method of constructing a load bearing structure, said method comprising: constructing a lightweight intermediate structure having a hollow framework comprising an interconnected network of tubular components; filling the interconnected network of tubular components with a fluid composition; and hardening the fluid composition such that the previously hollow framework is structurally reinforced to transform the lightweight intermediate structure into the load bearing structure.
2. The method of claim 1, further comprising: constructing the intermediate structure in a first location; and transporting the intermediate structure from the first location to a second location and securing the intermediate structure in place.
3. The method of claim 1 or 2, wherein the tubular components from which the hollow framework is constructed are formed from plastic materials, and preferably acrylonitrile butadiene styrene (ABS).
4. The method of claim 2 or 3, wherein the intermediate structure is transported by air from the first location to the second location.
5. The method of any of the preceding claims, wherein said intermediate structure is constructed such that it is capable of retaining the shape of the structure until the shape has been reinforced by the hardening of the fluid composition within the interconnected network of tubular components.
6. The method of claim 6, wherein the intermediate structure is self-supporting.
7. The method of any of the preceding claims, further comprising: providing temporary support means to help retain the shape of the intermediate structure until such has been reinforced by the hardening of the fluid composition within the interconnected network of tubular components.
8. The method of claim 7, wherein the temporary support means are provided by pumping compressed gas into the hollow framework.
9. The method of any of the preceding clams, wherein the hollow framework is provided with at least one inlet valve assembly and at least one outlet valve 5 assembly.
10. The method of claim 9, further comprising pumping the fluid composition into the interconnected network via said at least one inlet valve.
11. The method of claim 9 or 10, further comprising applying a vacuum to the at least one outlet valve assembly to draw the fluid composition through the lo interconnected network and out of the outlet valve assembly.
12. The method of any of the preceding claims, wherein the hollow framework is constructed from an interconnected network of single plastic tubular components.
13. The method of any of claims 1-11, wherein the hollow framework is constructed from an interconnected network of multiple smaller tubular components connected together to form pipe constructs.
14. The method of claim 13, wherein the smaller pipes are secured around the outer circumference of a larger hollow pipe.
15. The method of claim 13, wherein the smaller pipes are twisted together.
16. The method of any of the preceding claims, wherein the fluid composition is fibreglass resin.
17. A bridge constructed using the method of any of the preceding claims.