WO2011135322A1

WO2011135322A1 - Fire protection for buildings

Info

Publication number: WO2011135322A1
Application number: PCT/GB2011/050626
Authority: WO
Inventors: David Woolstencroft
Original assignee: David Woolstencroft
Priority date: 2010-04-30
Filing date: 2011-03-28
Publication date: 2011-11-03
Also published as: GB201007259D0; EP2563985A1; US20130067856A1

Abstract

When a steel structure is erected vertical columns of the structure typically comprise I-sections. In order to provide fire protection for the I-sections and so improve the resistance to fire of the steel structure a column protection system (8) has been developed. The column protection system (8) comprises column protection elements (10a, 10b) which are placed around an I-section (12) the column protection elements (10a, 10b) secure to the I-section (12). Horizontal beams may also be protected by the column protection system.

Description

Fire Protection for Buildings

This invention relates to a fire protection system for a building structure, in particular, but not limited to, a fire protection system for a steel frame structure.

Steel structures typically form the main strength and support in modern buildings. Consequently, it is very important to protect such a steel structure in the event of a fire. If the steel structure is subject to excessive heat then the structure can fail causing the collapse of the building.

A previous attempt at protecting a steel structure consisting of a plurality of circular hollow section columns has been made by applying an intumescent material coated onto the external surfaces of the columns. In the event of a fire the intumescent material expands and provides some heat resistance to fire.

A disadvantage of such a system is that a space of at least 50 mm must be left between the metal casing and any objects placed close to it to ensure that the intumescent material can expand and function properly.

It is an object of the present invention to address the above mentioned disadvantage.

According to an aspect of the present invention there is provided a heat/fire protection system for a structural assembly comprising a plurality of cover elements, each of the cover elements comprising an attachment portion and a body portion, wherein the body portion provides both structural rigidity and heat/fire protection.

The heat/fire protection system is preferably a heat/fire protection system for a structural assembly, preferably an assembly of steel columns and beams. The heat/fire protection system may be a heat/fire protection system for columns . The body portion is preferably adapted to provide heat/fire protection to a steel column or beam, which may be an I-section.

The body portion is preferably adapted to withstand temperatures in excess of those that can be withstood by steel before failure. Preferably, the body portion is adapted to withstand temperatures in excess of 550°C before failure. The body portion may be made of a polymeric material, which may be glass-reinforced. The body portion may be made of a ceramic material.

The body portion is preferably self-supporting.

The cover elements are preferably adapted to surround elements of the structural assembly. Preferably, two cover elements are adapted to cover a circumference of one of the elements of the structural assembly.

The cover elements may be adapted to fit end to end, to thereby cover the length of an element of the structural assembly using a plurality of cover elements. The cover elements may include interengaging projections and recesses or cut-outs to allow two cover elements to surround an element of the structural assembly and engage with one another. The projections and recesses/cut-outs may be on peripheral edges, preferably longitudinal peripheral edges, of the cover elements.

The cover elements may be provided in lengths of approximately lm to 2m.

The attachment portion may comprise a plurality of attachment elements. The attachment portion may comprise resilient hook portions, which may be attachment elements adapted to engage an element of the structural assembly or another cover element. The cover elements are preferably adapted to snap fit onto the element of the structural assembly or the other cover element .

The resilient hooks may be curved with a tip pointing towards the body portion.

The resilient hooks may be located on edges, preferably longitudinal edges, of the body portion. The attachment portion may be a collar, preferably being adapted to be secured to a structural member, such as an I-section . Each cover element may include at least two collars, preferably adapted to be located at or close to opposite ends of an element of the structure to be protected. The attachment portion is preferably adapted to receive the body portion on an exterior face thereof.

Preferably, the body portion is a sleeve, which may be adapted to engage the attachment portion. Preferably, the body portion is secured to the attachment portion.

The body portion may include at least one end portion adapted to be located at an end of the sleeve. The at least one end portion may be made of a moulded material, which may be the same material as the body portion. The at least one end portion advantageously provides a fire stop, to prevent a fire spreading into the interior of the body portion . The cover element may be adapted to leave ends of a structural element uncovered, which ends may have an intumescent material applied thereto.

The cover element may comprise inner and outer sections.

The inner section may be a thermal insulation material, such as rock wool or mineral wool or other insulating material. The inner section may be in a preformed shape, adapted to fit between a structural member and the outer section.

The outer section may be made of a material that holds its shape. The outer section is preferably adapted to protect the inner section from a blast in a fire or other emergency situation.

Alternatively, the inner section may be chosen for its rigidity, i.e. to hold its shape, with the outer section being an intumescent material. The inner section may comprise a self-supporting material.

The invention extends to a structural member, which may be a beam or column, preferably an I-section, having a cover element as described above located thereon.

The invention extends to a cover element as described in the above aspect.

The invention extends to a structure comprising a fire protection system and a structural assembly as described above . According to another aspect of the present invention there is provided a method of protecting a structural assembly from heat/fire, the method comprising fitting a plurality of cover elements to the structural elements assembly, wherein body portions of the cover elements provide both structural rigidity to the cover elements and heat/fire protection to the structural assembly.

The reference to heat/fire should be taken to extend to protection from fire and/or heat.

According to another aspect of the present invention there is provided a method manufacturing a protected structural member comprising: securing at least one attachment portion to a structural element; and

securing a body section over the at least one attachment portion, wherein the body portion provides both structural rigidity and heat/fire protection.

All of the features disclosed herein may be combined with any of the above aspects, in any combination. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a schematic cross-sectional view from above of a structural I-section having two column protection elements secured thereto;

Figure 2 is a schematic perspective side view of one of the column protection elements showing attachment clips thereof;

Figure 3 is a schematic cross-sectional view from above of a section embodiment of a column protection system;

Figure 4 is a schematic view of a structural assembly having a column protection system in position;

Figure 5 is schematic perspective view of a bracket of an alternative embodiment of column protection;

Figure 6 is a schematic cross-sectional view of Figure 5; Figure 7 is a schematic perspective view of a completed form of the alternative embodiment of column protection; and Figure 8 is a schematic cross-sectional view of Figure 7.

When a steel structure is erected vertical columns of the structure typically comprise I-sections. In order to provide fire protection for the I-sections and so improve the resistance to fire of the steel structure a column protection system has been developed.

The column protection system 8 comprises column protection elements 10a and 10b which are placed around an I-section 12 the column protection elements 10a and 10b secure to the I-section 12 by means of clips 14a (see Figure 2) . Horizontal beams may also be protected by the column protection system. The column protection elements 10a and 10b are made of a polymeric moulding material, which may be glass reinforced. An alternative material would be to use a ceramic material. The benefits of the material used are that it is stable under heat and doesn't intumesce.

The benefits of such materials are also that they can be drilled, sawn and glued, as appropriate. The material is also impact resistant. The column protection elements are typically provided in lengths of approximately lm to 1.5m. This would allow the usual height between floors of an I-section column of 3m to be protected with a number of lengths of the column protection elements secured along the column.

In more detail, the column protection elements lOa/b have a curved body, an outer wall of which may be semi-circular or form a semi-oval in cross-section. Of course other shapes can be used also.

Interengaging fingers 16a and 16b are provided on each of the column protection elements 10a and 10b, which fingers 16a, 16b allow the column protection elements 10a, 10b to mate and form a close fit with one another when placed in the positions shown in Figure 1. The clips 14a may be provided on wedge supports 18. The wedge supports provide a location for the clips 14a to be secured to the main body of the column protection elements 10a, b. The wedges 18 also allow the spacing between the clips to be set so that adjacent clips on opposite sides of a column protection element lOa/b can receive a flange of the I-section 12 between them.

As can be seen in Figure 1 the clips 14a are curved and point towards a main body of the column protection element. This has been done so that when a concave side of a column protection element is pushed towards a flange of an I-section the column protection element can be pushed onto the I-section causing the clips 14a to be pushed to the side to allow the column protection element to engage the flange of the I-section. Once passed the flange the clips 14 can spring back into their original position. As can be seen from Figure 1 in the secured position the clips retain the column protection element in position relative to the I-section 12. Another column protection element is secured to the opposite flange of the I-section in the same way. As can be seen from Figure 1 the fingers 16a and 16b interdigitate to cause the two column protection elements 10a and 10b to engage with one another and form a continuous external surface around the I-section 12. The continuous external surface provides excellent fire protection.

With the column protection system described above, an external temperature outside the column protection elements may be 1000°C, whilst still retaining a temperature of below 550°C at the I-section. Consequently, excellent fire protection is provided by the system described. Protection for at least two hours in a fire situation is provided. An alternative embodiment for securing the column protection elements 10a and 10b to the I-section is shown in Figure 3. Like numerals have been used where like parts are used. In this embodiment instead of the clips 14a being used to secure the column protection elements 10a and 10b to the I-section the clips are used to secure the two column protection elements 10a and 10b to each other. Similar clips are provided to those described in relation to Figures 1 and 2, but the location of those clips is changed to peripheral edges of the column protection elements 10a and 10b. The two clips 14a engage with one another to secure the two column protection elements 10a and 10b together around the I-section 12. A clip on one side may alternatively engage with a flange on the other side . In other respects the embodiment shown in Figure 3 functions and is used in the same way as the embodiment shown in Figures 1 and 2.

Figures 5 to 8 show a third embodiment of column protection system. In this embodiment collars 30 are secured to the I-section 12, for example with brackets 32 secured to flanges of the I-section 12.

The collars 30 are in the form of a ring, which may be circular, or could be oval. The collars receive a sleeve 34, which is secured to the collars 30, for example with adhesive or with fixing means. The sleeve 34 is made of the same material as the column protection elements 10a and 10b mentioned in relation to the first embodiment.

End pieces 36a-d are inserted into both open ends of the sleeve 34, to close the gap between the sleeve 34 and the I-section 12. The end pieces 36a-d may be made of the same material as the sleeve 34, which means that they are advantageously mouldable. The end pieces 36a-d provide a fire-stop to prevent the passage of fire between the I- section and the sleeve 34. Alternative fire-stopping material can also be used, as are well known in the art. The exposed ends of the I-section 12 are then coated with an intumescent material. The columns can be prepared off-site, which reduces labour costs compared to fitting a column protection system on site . A variant on this system is to fill the sleeve 34 with insulating material such as rock wool or mineral wool, which could be provided in pre-formed shapes to slide inside the sleeve 34. The thickness of the sleeve 34 is chosen to suit a particular purpose. For example a thicker sleeve 34 may be 70mm thick, where it is to be used in a car park to have some impact protection, or another location where impacts are likely.

The sleeve may be 10-25mm thick where there is less chance of an impact, but insulation is less likely to be needed or used. For a thin version the sleeve may be 5 to 10mm thick to provide some blast protection with heat protection being given by insulation.

A further alternative is to have a sleeve of substantially rigid, or self-supporting, material that will hold its shape. An intumescent material is applied to the sleeve to provide protection from fire. In this alternative space must be left around the protected column to allow for expansion of the intumescent material in a fire situation.

The invention may also be used for elements other than columns, such as horizontal or diagonal beams. Also, the beams need not be I-sections. In particular, the second or third embodiments could be used around any shape of beam.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment ( s ) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A heat/fire protection system for a structural assembly comprises a plurality of cover elements, each of the cover elements comprising an attachment portion and a body portion, wherein the body portion provides both structural rigidity and heat/fire protection.

2. The heat/fire protection system of claim 1, which is a heat/fire protection system for a structural assembly columns and beams.

3. The heat/fire protection system of any preceding claim, wherein the body portion is adapted to provide heat/fire protection to a steel column or beam.

4. The heat/fire protection system of any preceding claim, wherein the body portion is adapted to withstand temperatures in excess of those that can be withstood by steel before failure.

5. The heat/fire protection system of any preceding claim, wherein the body portion is self-supporting.

6. The heat/fire protection system of any preceding claim, wherein the cover elements are adapted to surround elements of the structural assembly.

7. The heat/fire protection system of any preceding claim, wherein the cover elements include interengaging projections and recesses or cut-outs to allow two cover elements to surround an element of the structural assembly and engage with one another.

8. The heat/fire protection system of any preceding claim, wherein the attachment portion is a collar adapted to be secured to a structural member, such as an I- section.

9. The heat/fire protection system of any preceding claim, wherein the cover element comprise inner and outer sections .

10. The heat/fire protection system of claim 9, wherein the inner section is a thermal insulation material, optionally rock wool or mineral wool or other insulating material .

11. The heat/fire protection system of claim 10, wherein the inner section is in a preformed shape, adapted to fit between a structural member and the outer section.

12. A structural member, optionally a beam or column, incorporating a cover element as claimed in any one of claims 1 to 11.

13. A cover element as claimed in any one of claims 1 to 11.

14. A structure comprises a fire protection system and a structural assembly as claimed in any one of claims 1 to 11.

15. A method of protecting a structural assembly from heat/fire, the method comprising fitting a plurality of cover elements to the structural elements assembly, wherein body portions of the cover elements provide both structural rigidity to the cover elements and heat/fire protection to the structural assembly.

16. A method of manufacturing a protected structural member comprising:

securing at least one attachment portion to a structural element; and