TECHNICAL FIELD

This disclosure relates to an insert for hollow composite sections that are used in structural or industrial applications. The insert may take the form of a block and may be used to strengthen the hollow composite section. The insert may also be used to join the hollow composite section (e.g. to another hollow composite section). Also disclosed is a sleeve for a composite polymer/fibre section.

BACKGROUND ART

Hollow composite sections may be used in a multitude of structural or industrial applications. For example, as advancements are made in the field of composite materials, both in design and manufacture, traditional building materials such as timber and steel may increasingly be replaced in favour of e.g. pultruded composite sections. Factors contributing to this replacement include cost, weight and longevity in use. The two primary components of hollow composite sections - fibres and resins - can contribute to their relative strength. Fibres can carry the load (e.g. tensile load), while resins contain the fibres and help distribute the weight throughout the composite part as required. The resins can also provide a degree of compressive strength/resistance. By combining specific resins and fibre reinforcements it can be possible to customize the formulation of a hollow composite section to meet specific strength requirements for a desired application.

In many fields, it may be increasingly desirable, among other considerations, to utilise materials with a high specific strength (i.e. high strength-to-weight ratio). Producing parts that are both strong and lightweight can be important in some industries, for a variety of reasons, such as transportation, infrastructure and aerospace. For example, lightweight composites may be easy to handle and install, and may thus reduce costs on projects and help ensure adherence to regulations and standards. Furthermore, composites may hold up well against fatigue and may be resistant to environmental factors such as U.V. damage, temperature fluctuations, moisture and chemical exposure. Also, composites are by nature inherently corrosion-/rot- proof.

However, whilst composites may typically have higher specific and tensile strengths, they may not perform as well as some other materials (e.g. steel) when loaded under shear, bending, torsion or compression.

Crossarms are used by an electrical network to support multiple (e.g. high tension) wires/cables used in connecting power grids. Crossarms can be made of timber or metal (e.g. steel). More recently, composite crossarms have been used by an electrical network to support multiple (e.g. high tension) wires used in connecting power grids. Electrical networks may require crossarms to achieve a maintenance free design life of at least 50 years.

In use, these crossarms may be required to resist a multitude of various loads including static, dynamic, tensile, and wind loads. Whilst crossarms may be provided by manufacturers with standard sizes and drilling patterns, in some instances the crossarms may also require ad-hoc modifications so as to suit the needs of a non-standard structural or industrial application. Such ad-hoc modifications may increase the risk of the composite crossarm section failing when under load (e.g. when loaded in use by static, dynamic, tensile, and wind loads).

It is to be understood that a reference to the prior art herein does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.

SUMMARY Disclosed is an insert block for a composite polymer/fibre section. The insert block is formed from a high-density polymer and is configured such that, in use, the insert block is able to closely interface with at least two opposing walls of the composite polymer/fibre section. The insert block is also configured such that it is able to substantially (e.g. wholly) fill a hollow space defined between the at least two opposing walls of the composite polymer/fibre section. In use, when a force is applied to the adjacent portion of the composite polymer/fibre section, the force is able to transfer into the insert block. The insert block may thus improve the performance and longevity of composite polymer/fibre section. Further, use of the inset block may enable the use of a composite polymer/fibre section that is produced at a lower cost (e.g. thinner, lesser volume, etc.) whilst still being fit-for- purpose (e.g. of sufficiently strength), especially when enhanced by the insert block as disclosed herein.

The terminology “substantially fills”, as employed in relation to the insert block in the composite polymer/fibre section, is to be understood as meaning that the block fills the hollow space so that a force applied to the adjacent portion of the section (i.e. between the at least two opposing walls of the section) is able to transfer (or be transferred) into the insert block.

Whilst typically the composite polymer/fibre section has a square or rectangular cross-sectional profile, in some embodiments, the composite polymer/fibre section may have a trapezoidal cross-sectional profile. In other embodiments, the composite polymer/fibre section may have a circular or ovular cross-sectional profile wherein the at least two opposing walls are diametrically opposed portions of the circular or ovular section’s interior. In some embodiments, variations are contemplated where the cross-sectional profile of the composite polymer/fibre section has any number of walls (e.g. 5, 6, 8, etc.), and such that at least two walls of the composite polymer/fibre section are opposed to each other whereby an insert block may be located therebetween. In each such case, the insert block can be configured to suit the cross-sectional profile of the section.

In some embodiments, the insert block may be configured to closely interface with only a portion of the opposing walls along the longitudinal length of the composite polymer/fibre section. For example, the insert block may be located just at that part of the section where loading is to take place in use. In some embodiments, the insert block does not need to fill the entire cross- section of the composite polymer/fibre section. For example, the insert block may instead substantially (e.g. wholly) fill the hollow space defined (i.e. that spans) between at least two opposing walls of the composite polymer/fibre section. In such case, the hollow space that is filled can have a smaller cross-sectional area than the cross-sectional area of the composite polymer/fibre section. For example, in some embodiments where the section is rectangular, the insert block may only closely interface with two opposing side walls of the composite polymer/fibre section, thereby filling a hollow space defined between the two opposing side walls but whilst not closely interfacing with the upper and lower opposing walls of the composite polymer/fibre section.

In some embodiments, the insert block may closely interface with all of the opposing walls that form a perimeter of the composite polymer/fibre section cross-section (i.e. the insert block may be configured to substantially or wholly fill the cross-sectional internal profile of the particular section). In such an embodiment, the hollow space that is filled has an area equal to the cross-sectional area of the composite polymer/fibre section. Thus, variations are contemplated whereby the insert block may be formed to be of a size and a shape so as to substantially or wholly fill the hollow space defined by a particular composite polymer/fibre section.

In some embodiments, the insert block may be configured such that it is press- or force-fit into the section so as to locate between the at least two opposing walls of the composite polymer/fibre section. In this regard, the cross-sectional area and profile of the insert block may be the same as or just slightly (e.g. by millimetres or even less) greater than the cross-sectional area defined between the at least two opposing walls of the composite polymer/fibre section.

The insert block may be press- or force-fit into the section via a hydraulic ram (or similar apparatus). For example, the section can be restrained, and the insert block can then be press- or force-fit into the section via the ram until the block is located at a desired location. Such a location may correspond to the insert block being located partially or fully in the section.

For example, when the insert block is partially located in the section, it can be used to join the section to another (e.g. adjacent) section, e.g. so as to form a joint. The joint may be defined at a comer of a structure comprising the two sections. In this regard, an open end of the composite polymer/fibre section may be mitre cut to help define the joint. The adjacent section may also be mitre cut to help define a tight joint. Alternatively, the joint may be defined in a length of two or more longitudinally extending sections (i.e. to be joined end-to-end), etc.

The positive pressure generated by the press-fit/force-fit interface of the insert block with the at least two opposing walls of the composite polymer/fibre section may function to improve the efficiency of the force transfer between the insert block and the composite polymer/fibre section walls during loading. The positive pressure generated by the press-fit/force-fit interface of the insert block with the opposing walls of the composite polymer/fibre section can also support the walls in use (e.g. when a compressive force, shear force, torsional force, momentary force, etc. is applied to and/or between the walls in use).

In some embodiments, the force applied to the composite polymer/fibre section may be at least one of a torsion force applied along (e.g. along the length of) the composite polymer/fibre section, a compression force applied against (e.g. to act between) the at least two opposing walls, a shear force applied e.g. at a location where the composite polymer/fibre section is mounted to a structure (e.g. mounted to an upright post, pole, wall, etc.), and/or a momentary force applied e.g. at a location remote from where the composite polymer/fibre section is mounted to the structure.

In some embodiments, the insert block may comprise at least one hole that is formed (e.g. bored) therein. For example, the at least one hole may be formed (e.g. bored) therein prior to locating the insert block within the composite polymer/fibre section. The at least one hole may be arranged in the insert block such that it is able to substantially align with a corresponding at least one hole through an adjacent wall of the at least two opposing walls of the composite polymer/fibre section.

In some embodiments, the at least one hole of the insert block may pass through (i.e. fully through) the insert block. In some embodiments, the at least one hole of the insert block may be adapted to receive and/or retain a fastener therein. The hole may be a pilot hole or may be sized to accommodate the fastener therein. Such a fastener may be employed to mount the composite polymer/fibre section to a structure (e.g. mounted to an upright post, pole, wall, etc.). For example, such a fastener may take the form of one or more bolts for mounting the composite polymer/fibre section to the structure.

In some embodiments, a self-tapping fastener may be used. In such embodiments, the insert block and/or composite polymer/fibre section may not require a hole to be prior-formed therein. In some embodiments, the self-tapping fastener may be secured by engagement with the insert block alone or in combination with the composite polymer/fibre section. For example, the self-tapping fastener can be caused to tap through both the composite polymer/fibre section and the insert block, or the composite polymer/fibre section may have a pre-formed hole through which the self-tapping fastener is passed to then tap into the insert block alone.

In some embodiments, a washer may be used on at least one end of the fastener. This may further improve the load distribution at the contact point between the fastener and the composite polymer/fibre section through the insert block.

In a particular embodiment, one or more fasteners may be used for mounting a composite polymer/fibre crossarm section to a structure such as a post or pole.

The insert block located within the crossarm section can allow for the crossarm section to be tightly secured, via the one or more fasteners, to the post or pole.

The insert block can enable the crossarm section to better resist fracturing and failure due to compressive forces applied via the fasteners, washers, etc. and can also better enable the crossarm section to resist longitudinal, momentary, torsional/twist, shear, etc. forces applied to the crossarm and its mounting with the post or pole in use.

In some embodiments, the high-density polymer of the insert block may be polyethylene (e.g. high-density or ultra-high-density polyethylene). In other embodiments, the high-density polymer of the insert block may be a polyurethane, polypropylene, polystyrene, ABS resin, etc. In some embodiments, the high- density polymer of the insert block may exhibit at least one of: high impact strength, high tensile strength, high levels of energy absorption, high levels of abrasion resistance, high levels of resistance to stress cracks, high levels of torsion resistance. In some embodiments the high-density polymer may be marine grade polyethylene. In some embodiments, where the high-density polymer is marine grade polyethylene, the insert block may be able withstand the effects of salt water, moisture, and/or direct sunlight. In some embodiments where the high- density polymer is marine grade polyethylene, the insert block may have improved resistance to splintering, rotting, or swelling in comparison with regular high-density polyethylene. In some embodiments where the high-density polymer is marine grade polyethylene, the longevity of the insert block may be improved. In some embodiments, the polymer may have additives thereto which improve the resistance salt water, moisture, direct sunlight, splintering, rotting, or swelling.

Also disclosed herein is a composite section system. The system comprises a composite polymer/fibre section and an insert block. The composite polymer/fibre section and the insert block can each be as set forth above. A section that comprises the insert block can e.g. be used as a crossarm, etc.

In this regard, the composite polymer/fibre section has a hollow space defined between at least two opposing walls thereof. The insert block is formed from a high-density polymer and is adapted such that, in use, it is able to closely interface with the at least two opposing walls of the composite polymer/fibre section. Thus, the insert block is able to substantially (e.g. wholly) fill the hollow space defined between the at least two opposing walls. The insert block may thus impart its strength to the composite polymer/fibre section, thereby improving the performance and longevity of the resultant composite section of the system (i.e. the block and section may work together to provide an additional composite effect). The composite section of the system may also be produced at lower cost (e.g. in comparison to prior art systems) whilst still being a sufficiently strong product (e.g. due to the composite effect of the block and section working together).

As set forth above, in some embodiments of the system, the hollow space (being substantially or wholly filled by the insert block) may be fully defined by the area and shape of the cross-sectional area of the composite polymer/fibre section (i.e. the block may fill the entirety of the cross-section).

As set forth above, in other embodiments of the system, the area and shape of the hollow space may not be the same as the area and shape of the cross-sectional area of the composite polymer/fibre section (i.e. the block can partially fill the cross- section).

As set forth above, in some embodiments of the system, the length of the hollow space to be filled by the block may be less than the longitudinal length of the composite polymer/fibre section (e.g. the block may extend for only a part-length of the section, and may be located in the section only where it is required).

As set forth above, in some embodiments of the system, variations may be contemplated (as above) where the composite polymer/fibre section has any number or walls. In such variations, the at least two walls of the composite polymer/fibre section can be opposed to each other whereby the insert block can be located therebetween.

As set forth above, in some embodiments of the system, variations may be contemplated where the insert block is formed to be of a size and a shape so as to substantially or wholly fill the hollow space defined by the particular embodiment/form of the composite polymer/fibre section. The block may be partially oversized to increase the interference of its fit with/within the section.

As set forth above, in some embodiments of the system, the insert block may be further adapted such that, in use, a force (e.g. tension, compression, longitudinal, momentary, torsional/twist, shear, etc.) that is applied to the adjacent portion of the composite polymer/fibre section is able to be transferred into the insert block.

As set forth above, in some embodiments of the system, the insert block may be located such that a portion of the insert block protrudes from an open end of the composite polymer/fibre section. For example, the open end of the composite polymer/fibre section may be mitre cut (e.g. to help define a joint at the open end). An adjacent (to-be-joined) section may also be mitre cut to help define a resultant tight joint. Alternatively, two or more longitudinally extending sections can be joined by one or more insert blocks protruding from one or each open end of a given one or more of the sections (i.e. to join the adjacent sections in an end-to- end orientation).

As set forth above, in some embodiments of the system, the portion of the insert block that protrudes from the composite polymer/fibre section may be adapted to be located in, so as to substantially or wholly fill, a second hollow space. The second hollow space may be defined in the open end of an adjacent (e.g. composite polymer/fibre) section. Alternatively, the second hollow space may be defined in some other structure (e.g. along the length of an upright post, pole, wall, etc.). The insert block can closely interface with at least two opposing walls that at least partially define the second hollow space (e.g. the two opposing walls may form part of a second composite polymer/fibre section). Thus, the insert block may also substantially or wholly fill the second hollow space.

As set forth above, in some embodiments of the system, the insert block may be located intermediate the ends of the composite polymer/fibre section (e.g. at a location where the section is to be mounted to e.g. an upright post, pole, wall, etc., such as in crossarm applications). As set forth above, in some embodiments of the system, the insert block may be press- or force- fit (e.g. by a hydraulic ram) into location between the at least two opposing walls of the composite polymer/fibre section. The resultant positive pressure generated by the press/force-fit interface between the block and the opposing walls of the section can improve the additional composite effect and the efficiency of force transfer into the insert block during loading (e.g. in-use loading of the section arising from tension, compression, longitudinal, torsional, shear, momentary, etc. forces applied thereto).

As set forth above, in some embodiments of the system, the insert block may comprise at least one hole that is (e.g. prior) formed or bored therein (e.g. partially or fully therethrough). The or each hole can align with a corresponding hole through an adjacent wall (e.g. one or more of the walls) of the section. For example, opposing holes in opposing walls of the section can align with a hole that passes through the insert block. A fastener (e.g. bolt) can be passed therethrough and can be used to mount the section to another structure (e.g. post, pole, wall, etc.).

As set forth above, in some embodiments the system may further comprise (e.g. it may be supplied with) at least one fastener. The insert block can be adapted to receive and/or retain the fastener therein (e.g. via the at least one hole of the insert block). As set forth above, the fastener may be one or more bolts, or one or more self-tapping fasteners may be used (e.g. a self-tapping screw, coach bolt, etc.).

As set forth above, in some embodiments of the system, the high-density polymer of the insert block may be polyethylene such as high-density polyethylene or ultra-high-density polyethylene (or it may comprise a high-density: polyurethane, polypropylene, polystyrene, ABS resin, etc.). In some embodiments the high- density polymer may be marine grade polyethylene to improve the performance and longevity of the insert block.

As set forth above, in some embodiments of the system, the system may further comprise one or more washers. Each of the one or more washers may be located, in use, adjacent to a wall of the at least two opposing walls of the composite polymer/fibre section so as the surround the corresponding at least one hole therethrough.

As set forth above, in some embodiments of the system, the insert block may comprise one or more air voids within the material of the insert block. In some embodiments, the one or more air voids may be caused by the addition of an aeration and/or foaming agent during formulation of the insert block material.

Also disclosed herein is an insert block for a composite polymer/fibre section of the type that has a hollow space defined between at least two opposing walls, the insert block being formed such that, in use, the insert block is able to closely interface with two or more of the at least two opposing walls of the composite polymer/fibre section so as to define a substantially continuous structure therebetween, whereby, in use, a force applied to the composite polymer/fibre section in a region adjacent the insert block is able to transfer from the composite polymer/fibre section into the insert block.

In some embodiments of the insert block, the substantially continuous structure of the insert block may comprise one or more air voids therewithin. In some embodiments, the one or more air voids may be caused by the addition of an aeration and/or foaming agent during formulation of the insert block material. In some embodiments, the insert block may be arranged as a honeycomb structure that comprises a greater total volume of the insert block material than a total volume of the one or more air voids within the insert block.

In some embodiments of the insert block, the substantially continuous structure of the insert block may comprise a high-density polymer.

In some embodiments of the insert block, the insert block may be further defined by the features of the insert block described above. Also disclosed herein is a sleeve for a composite polymer/fibre section of the type that has a hollow space defined between at least two opposing walls. The sleeve is configured such that, in use, the composite polymer/fibre section is able to be inserted within the sleeve, whereby the sleeve is able to closely interface with two or more of the at least two opposing walls of the composite polymer/fibre section. The sleeve is further configured such that, in use, a concentrated force applied to the sleeve adjacent to one of the walls of the composite polymer/fibre section is able to be transferred into but spread over the wall of the composite polymer/fibre section.

In some embodiments, the sleeve may be configured to locate around the composite polymer/fibre section and to interface with exterior facing surfaces of the composite polymer/fibre section.

In some embodiments, the sleeve may be configured such that the composite polymer/fibre section is inserted therein in a press-fit.

In some embodiments, the sleeve may comprise at least one hole that is formed therein. The at least one hole is arranged such that it is able to substantially align with a corresponding at least one hole through an adjacent wall of the at least two opposing walls of the composite polymer/fibre section. In some embodiments, the at least one hole may pass through a wall of the sleeve. In some embodiments, the at least one hole of the sleeve may be adapted to receive a shank of a fastener therethrough, with a head of the fastener being received at an external surface of the sleeve adjacent to the at least one hole.

In some embodiments, the sleeve may be formed from a high-density polymer such as high-density or ultra-high-density polyethylene.

In some embodiments of the sleeve, an insert block as defined above may be inserted, in use, into the composite polymer/fibre section to a location that generally aligns with the sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with reference to the accompanying drawings in which

Fig. 1 is a partially transparent perspective view of a first embodiment of an insert block when partially inserted within a composite polymer/fibre section.

Fig. 2 is a partially transparent perspective view of a second embodiment of an insert block when partially inserted within a composite polymer/fibre section.

Fig. 3 is a partially transparent perspective view of a third embodiment of an insert block when partially inserted within a mitre cut end of the composite polymer/fibre section.

Fig. 4 is a partially transparent perspective view of the third embodiment of the insert block when partially inserted within the mitre cut ends of two adjacent composite polymer/fibre sections.

Fig. 5 is a partially transparent perspective view of the first embodiment of the insert block when inserted intermediate the ends of the composite polymer/fibre section.

Fig. 6 is a partially transparent perspective view of the second embodiment of the insert block when inserted intermediate the ends of the composite polymer/fibre section.

Fig. 7 is a partially transparent perspective view of an embodiment of a composite section system when installed as a crossarm using a plurality of fasteners.

Fig. 8 is a partially transparent perspective view of a second embodiment of a composite section system when installed as a crossarm using a plurality of fasteners.

Fig. 9 is a perspective view of an embodiment of a composite section system comprising two insert blocks installed therein. Fig. 10 is a perspective view of a fourth embodiment of an insert block where the insert block comprises grooves along one or more peripheral surfaces.

Fig. 11 is a perspective view of an embodiment of a composite section having a sleeve installed over the outer surface of the composite section.

DETAILED DESCRIPTION

In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised, and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

Various embodiments of the disclosure are shown in Figs. 1 to 10 and will now be variously described.

An insert block for a composite polymer/fibre section is shown in the form of a solid polymeric block 20. The composite polymer/fibre section can take the form of a composite section 10 that is typically formed by pultmsion (i.e. when fibres or woven or braided strands are impregnated with resin and pulled through a heated die whereby the resin undergoes polymerization). In the composite section 10, the fibres can be of glass, carbon, etc. and the polymer resin can be a polyester, polyurethane, vinyl-ester or epoxy.

The block 20 is made from a high-density polymer that is formed into a shape such that it can be press-fit or force-fit as a dense wedge into a hollow space 18 that is defined within the composite section 10. The block 20 is forced into the composite section 10 via a hydraulic ram (or similar apparatus). During such forcing, the block can deform to at least some extent to facilitate its passage into the section. Typically, the section is restrained (e.g. clamped) prior to block insertion, and the block 20 is then press- or force-fit into the section 10 via the ram, until the block is located at a desired location.

The final location of block 10 can correspond to the block being located partially (Figs. 1-4) or fully (Figs. 5-9) within the composite section 10. The block can be generally the same size or it can be slightly oversized (e.g. by a few millimetres or even microns) in comparison to the composite section in which it is to be located.

The block 20 is configured to substantially, and typically wholly, fill at least a portion of the hollow space 18, in that it bridges between two opposing internally facing walls of the composite section 10. The block 20 is configured to closely interface with the opposing internal walls of the composite section 10, applying a positive pressure thereagainst, and is thus firmly held in place in the composite section 10 once in its desired location.

In this regard, Figs. 1-8 & 10 each show a block that generally corresponds to (i.e. is able to fill) the cross-section of the composite section 10, whereas Fig. 9 shows two separate blocks 20’ and 20” that each only partially fill across a respective portion of the cross-section of the composite section 10’. Further, in the embodiment of Fig. 9, each block 20’ and 20” only fills a portion of the space between two opposing sidewalls within the cross-section of composite section 10’. Both of 20’ and 20” substantially or wholly fill across the cross-section of their respective portions of the composite section 10 so as to closely interface with at least two opposing internally facing walls of respective hollow spaces 18, 18”.

The press- or force- fit arrangement of the block 20 in each case enables the transfer of a force applied to the composite section 10, 10’ through to an adjacent portion of the block 20, whereby the force may be more efficiently absorbed. The types of forces which may be absorbed are described more fully below. Further, the block 20 in each case provides an additional composite structural performance characteristic to the composite section 10, 10’ in which it is located. In other words, it adds to the composite effect imparted by the fibres embedded within the polymer resin matrix of the composite section. The block in each case enables the resultant section to better accommodate forces such as tension, compression, longitudinal, torsional, shear, momentary, etc.

As shown in Figure 10, the block 20 can have grooves 19, formed along one or more peripheral outer surfaces of the block 20. The grooves 19 may provide a space into which the block 20 can deform during insertion in a longitudinal direction into composite section 10. Such deformation into the grooves 19 may make it easier to insert the block 20 into the composite section 10.

Whilst the high-density polymer of the block 20 can be a polyurethane, polypropylene, polystyrene, ABS resin, and the like, typically the high-density polymer for block 20 comprises high density polyethylene (HDPE) or ultra-high density polyethylene (UHDPE). HDPE is employed because it is cost effective, readily available and is able to exhibit one or more of: high impact strength, high tensile strength, high levels of energy absorption, high levels of abrasion resistance, high levels of resistance to stress cracks, high levels of torsional resistance. UHDPE is very high performance, but a more expensive material.

Further, the HDPE can be of a marine grade, whereby the block 20 can be employed in applications where it is required to withstand the effects of salt water, moisture, and direct sunlight. Marine-grade HDPE also has improved resistance to splintering, rotting, or swelling. Thus, HDPE is typically employed for block 20 as it is available, easy-to- shape, generally low cost to produce, and can improve the in-use economics of a resultant composite-block- section. The block 20 can also improve the longevity of the composite section 10. Additives to the block can be employed that improve one or more of these resistive qualities.

Reference will now be made to Figure 1, and the axis illustrated therein, by way of example. In this regard, the block 20 can be adapted to have a height Z and a width X whereby it can substantially, or more typically wholly, fill at least a portion of the hollow space 18 in that direction. For example, the block 20 can e.g. wholly fill the hollow space 18 between two opposing internally facing walls in the X direction, but not the Z direction. Alternatively, the block 20 can wholly fill the hollow space 18 between two opposing internally facing walls in the Z direction, but not in the X direction. Typically, however, and as shown in Figure 1, the block 20 can be configured to wholly fill the hollow space 18 between two opposing internally facing walls in both the Z and X directions.

The composite section 10 shown in Figures 1 to 8 is generally of square or rectangular hollow section, whereas the composite section 10’ shown in Figure 9 has a U-shaped profile as well as a compartmentalized hollow section. Many other cross-sectional variations are contemplated in this disclosure. For example, the section can have a cross-section that is circular, ovular, triangular, trapezoidal, pentagonal, hexagonal, octagonal, etc. The composite section 10 can have non parallel opposing walls, such as when it is of circular cross-section. In each such case, the block can be adapted to substantially (more typically to wholly) fill at least a portion of the hollow space across generally opposed portions of the internally facing walls. Typically, the block 20 is configured and positioned at a location where the load is to be applied, concentrated, transferred, etc. in use of the composite section.

As illustrated in Figures 1 to 4, the block 20 is adapted to have a longitudinal length in the Y direction (see Y-axis in Fig.l) that is typically less than a length of the composite section 10 (although it is conceivable that the block could have the same or a similar length to the section 10, or even a length that is longer than the section 10). The block 20 is configured to be at least partially retained within the composite section 10.

In the embodiment of Fig. 9, a first block 20’ is adapted to have a longitudinal extent in the Y direction that is shorter than the length of the hollow space 18 of the composite section 10. Further, a second block 20” is adapted to have a longitudinal extent in the Y direction that is equal to the length of the hollow space 18 of the composite section 10. Both blocks 20’, 20”, regardless of the length in the Y direction, are configured to substantially or wholly fill the respective hollow spaces 18,18” so as to closely interface with at least a portion of their respective two opposing internally facing walls in the X direction.

For example, in the embodiments of Figures 1 to 4 the block can be located so as to partially protrude from the composite section 10. In this location, the block 20 can be used to join an adjacent composite section. In this regard, as illustrated in Figure 4, two adjacent composite sections 10 are able to be joined at a corner, along a mitre cut end 16 formed in the respective sections 10, with the block 20 partially press-fit into both sections to form a bridge (i.e. comer join) therebetween. To locate the block 20 in the corner of the respective sections 10, each may be restrained and clamped together, and the block then press- or force- fit into the location as shown from an opposite open end of the one of the sections. In a variation, the protruding block 20 retained in the end of one section can be pushed, relatively, into the open end of the adjacent section.

Likewise, the block 20 can be used to join adjacent composite sections lengthwise. For example, the open end of a like (or unlike) section 10 can be positioned to receive the protruding block 20 as shown in each of Figures 1 and 2. Again, to locate the block 20 at the join of the respective lengthwise-arranged sections 10, each may be restrained and clamped together end-to-end, and the block then press- or force- fit into the joining location from an opposite open end of the one of the sections. Again, in a variation, the protruding block 20 retained in the end of one section can be pushed, relatively, into the open end of the adjacent section.

Once the sections are so joined (e.g. in a corner, or lengthwise end-to-end), additional fasteners can be employed to further secure the adjacent sections together. Examples of such fastener arrangements are described hereafter.

In the embodiments illustrated in Figures 5-8, the insert block 20 is located intermediate the ends of (i.e. within) the composite section 10. Again, the block 20 can be press- or force- fit into the intermediate location from one of the opposite open ends of the composite section 10. The intermediate location can correspond to where the block is to be mounted to some other structure (e.g. post, pole, wall, etc.).

In another variation, not shown, a plurality of blocks 20 can be inserted along the longitudinal length of a single composite section 10 to e.g. discrete, respective, and optionally spaced locations along the length (e.g. when the section 10 has more than one mounting location), or the blocks can be in end-to-end abutment (e.g. for a full length of the section).

As shown in Figure 2, the block 20 can comprise a hole 22 therein. The hole 22 is typically preformed in the block (i.e. prior to it being inserted into the composite section 10). The hole 22 can be moulded or bored fully through the block 20, or it can be moulded or bored part-way into the block 20. The hole 22 can be configured as a pilot hole for a suitable fastener (e.g. for a self-tapping screw or coach bolt).

Thus, the terminology in relation to the block “substantially” filling the hollow space is to be understood as contemplating a block having one or more holes, passages and/or hollows therein (i.e. the block need not be completely solid).

The hole 22 can be aligned with a pre- or post-formed hole 23 in a wall of the composite section 10. When the hole 23 is post-formed, it can be drilled or cut through the wall of section 10. Thus, a fastener can be passed through the aligned holes 22, 23. When the fastener is a bolt that passes fully through each of the composite section 10 and block 20 (i.e. via the aligned holes 22, 23), an opposite end of the bolt can be secured with a nut, weld, split-pin, etc. This can further secure the block 20 in the section 10. A bolt may be selected that has sufficient length to enable the section 10 to be secured at a further structure (e.g. post, pole, wall, etc. - see Figs. 7 & 8).

As shown in Figures 4, 7 and 8, the block 20 can comprise a plurality of (e.g. two) holes 22 extending into one face (Figures 7 & 8) or into two respective faces (Figure 4) of the block 20. Again, each hole 22 is typically preformed in the block, and can be formed to extend fully through the block, or each hole 22 can extend part-way into the block 20. The use of two or more holes 22 and two or more corresponding fasteners 24 enables the section 10 to be secured at a further structure and to thereby resist rotation, twisting, torsion, etc.

As shown in each of Figs. 3, 4, 6, 7 and 8, the one or more holes 22 of the block are formed so as to substantially align with corresponding hole(s) 23 that are pre- or post- formed in an adjacent wall of the composite section 10.

For example, Figure 3 shows a fastener (e.g. bolt, coach bolt or screw) 24 that is secured either directly to the block 20 (e.g. adhesively or via self-tapping), or that is passed fully through the wall of composite section 10 via hole 23 and fully through the block 20 via hole 22. In the latter case, the opposite end of the fastener 24 can be secured (e.g. via a nut, weld, split-pin or similar) at an opposite side, optionally with the use of washers (described below).

It should be understood that the fastener 24 can be a variety of fastener types (e.g. bolt, coach bolt, screw, self-tapping screw, anchor bolt, pin, clip, hook, etc.). The particular fastener chosen is selected to be suitable for the particular application.

Figure 4 shows respective fasteners (e.g. bolt, coach bolt or screw) 24 that are secured either directly to the block 20 (e.g. adhesively or via self-tapping), or that are each passed fully through the wall of composite section 10 via hole 23, and fully through the block 20 via hole 22. In this latter case, the holes 22 can be offset, and the opposite end of each fastener 24 can again be secured (e.g. via a nut, weld, split-pin or similar) at an opposite side of the block 20. Thus, the fasteners 24 can help to secure a corner formation in a structure by joining two adjacent and mitred (i.e. at 16) composite sections 10 as shown.

Figure 6 shows a fastener (e.g. bolt, coach bolt or screw) 24 that is secured either directly (e.g. adhesively or via self-tapping) to the intermediately located block 20, or that is passed fully through the opposing walls of composite section 10 via the respective opposing holes 23 and fully through the block 20 via hole 22. In the latter case, the opposite end of the fastener 24 can be secured (e.g. via a nut, weld, split-pin or similar) at the opposite wall of composite section 10, optionally with the use of washers (described below). In a further variation, the fastener (e.g. bolt) 24 can have a sufficient length such that it can be connected to another structure (e.g. post, pole, wall, etc.).

Figures 7 and 8 each show a number of (i.e. two) respective fasteners (e.g. bolt, coach bolt or screw) 24 that are secured to pass fully through the intermediately located block 20, via the respective adjacent and opposing hole pairs 23 of composite section 10 and via the respective aligned block holes 22. The fasteners can be aligned vertically, horizontally or in a pattern (e.g. four fasteners can be employed and can form a square or diamond pattern). The opposite end of each fastener 24 is typically configured to be connected to another structure 30, 30’ such as a post, pole, etc. (e.g. Fig. 7 shows a post, pole 30 of square/rectangular cross-section, whereas Fig. 8 shows a post, pole 30’ of circular/oval/elliptical cross-section).

When the composite section 10 is of a rectangular cross-section, usually it is mounted to the post, pole 30, 30’ such that, when the section 10 is viewed in profile, one of the long rectangular sides of the section 10 faces the post, pole 30, 30’. Again, after tightening of the fasteners 24, this orientation of the section 10 better helps to spread and distribute the load over and through the section 10, and to the post, pole 30, 30’.

For example, when the structure is a post or pole such as 30, 30’, each fastener (e.g. each bolt) 24 can have a sufficient length such that it can pass fully through the post or pole and be secured at an opposite end thereof (e.g. via a nut, weld, or similar) - e.g. at an opposite side of the post or pole such as 30, 30’. Alternatively, an end of each fastener 24 may be configured to secure into the other structure 30, 30’ (e.g. by boring or tapping into the body of the structure, or into another insert block 20 located within the structure). The other structure 30, 30’ shown in Figures 7 and 8 can, for example, be an electrical or telecommunications pole, such that the composite section 10 can function as a cross-arm to support wires, cables and the like. The electrical or telecommunications pole can be of timber, metal (e.g. galvanised steel, aluminium, etc.), composite material, etc.

As above, when the other structure 30, 30’ is itself a composite fibre/polymer resin section, it too may be provided with an intermediately located block that can generally align in use with the block 20. Thus, the fastener(s) 24 can self-tap into the block of the other structure, or can again pass therethrough to be secured at an opposite side of the other structure (e.g. via a nut, weld, split-pin or similar, and typically with the use of washers).

The block 20 can absorb compression/compressive forces transferred by the fastener(s) 24 into the composite section 10 (and pole 30, 30’ when also incorporating a block 20), and thus can help to prevent cracking of the composite section (e.g. should the fastener(s) be over- tightened). Thus, the block 20 can assist the composite section 10 (and pole 30, 30’) to resist failure during installation from crush forces.

The block 20 can also assist the composite section 10 (and pole 30, 30’) to absorb and resist other forces and loads applied to the composite section 10 in use. These can include forces arising from bending moments applied to and along the length of the composite section 10, such as may arise from loading, for example, by items supported at or on the section 10 (including e.g. wires, cables, lights, etc.).

The forces and loads can also be variable in nature (e.g. arising from air and wind movement, gusts, human loads, animal interactions, etc.) that can be applied to the composite section 10 and to the items supported at or on the section 10. These forces and loads can also impart twisting and torsional forces to the section 10. Such loads can be most acute in the composite section 10 at and in the vicinity of the fastener(s) 24. Again, the block 20 can help to absorb at least a portion of the momentary, torsional and twisting forces/loads in the composite section 10 (and pole 30, 30’) at and in the vicinity of the fastener(s) 24.

Such forces and loads can also impart shear forces between the composite section 10 (and pole 30, 30’) and the fastener(s) 24. Again, the block 20 can help to absorb and resist at least a portion of such shear forces/loads.

As set forth above, washers 28 are typically also used on at least one end (and typically at both ends) of the fastener(s) 24, at a location where the fastener(s) 24 contact the composite section 10. The washers 28 help to improve the load distribution, and help spread the contact force, at the contact point between the fastener and the composite section 10 (and pole 30, 30’) through the insert block 20.

For example, in Figure 8, in use, when a fastener 24 is passed through a composite section 10, washers 28 can be located on either end of the fastener 24 (i.e. on one side of the composite section 10 and at another side of the pole 30’). Thus, as the fastener 24 is tightened against the composite section 10, the load is more efficiently/effectively spread around the fastener 24 by each washer 28, over the composite section 10 and into to the insert block 20 and over the pole 30, where such forces may be absorbed more efficiently/effectively. This may also reduce the likelihood of the composite section 10 and pole 30’ failing (e.g. fracturing, cracking, shearing, etc.) locally at the contact points adjacent to the opposing hole pairs 23 of composite section 10 and pole 30’.

Referring now to Figure 9, it will be seen that the composite section 10’ has a more complex (i.e. U-shaped) profile. In this regard, the composite section 10’ can comprise a plurality of (e.g. three) hollow spaces 18, 18’ and 18” that are separated from each other by a number of (e.g. two) internal dividing walls 12. In this embodiment, two insert blocks 20’ and 20” are press- or force- fit into portions of the hollow spaces 18 and 18” as shown, whereas hollow space 18’ comprises no such block. The blocks 20’ and 20” can also help the composite section 10’ to support other structures located in the central channel of the U-shaped composite section 10’. In this regard, one or more fasteners (e.g. bolts - not shown) can pass from one side of composite section 10’ (e.g. adjacent to block 20’), through e.g. a preformed hole in block 20’, through the other structure, through e.g. another preformed hole in the other block 20”, to the opposite side of composite section 10’. The blocks 20’ and 20” can thus help the composite section 10’ to accommodate the various of the forces and loads as outlined above.

Variations and modifications may be made to the parts previously described without departing from the spirit or ambit of the disclosure.

In a variation, the high-density polymer of the block can be aerated or foamed during its formulation, providing a honeycomb structure to the resultant cured block. The resultant block can comprise one or more air voids therethrough. This can ‘lightweight’ the block.

With such a honeycomb-like structure, the block is still able to define a substantially continuous structure having an overall density and continuity that is adapted to resist compression or torsional loading. In addition, the substantially continuous structure of the block can still enable the composite section to transfer into the block external forces applied to the composite section adjacent to the block, thereby reinforcing the composite section in use. For example, when a fastener is inserted through the composite section and tightened against the opposing outer walls of the composite section, the honeycomb-like block can absorb the compression force and assist in preventing the hollow composite section from deforming.

In a further variation, the high-density polymer of the block can comprise one or more supporting frames that are integrated within the otherwise substantially continuous structure of the block. For example, one or more plates or pipes can be arranged within the high-density polymer of the block so as to further strengthen the torsional resistance of the block. The supporting frames can be used to improve the load distribution, and help spread the contact force, at the contact point between the fastener and the composite section through the insert block. In some variations, the supporting frames can effectively define an internally embedded washer that at least partially replicates the function and performance of traditional washers (typically located at the contact point between the fastener and the outer surface of the hollow composite section) whilst advantageously being incorporated within the profile of the block.

In a further variation, the outer profile of the block can be formed as a sleeve of a metallic material such as steel. The metallic sleeve can hold captive the high- density polymer of the block and can improve the rigidity of the block as a whole. The metallic sleeve can also further improve the impact strength, tensile strength, and abrasion resistance of the block prior to insertion within the composite section. In a further variation, and with reference to Figure 11, a sleeve 120 for the composite section 110 can be provided. The sleeve 120 can function to absorb and spread the load applied to the composite section 110 by one or more fasteners.

The sleeve can e.g. be formed of the same material as the insert block 20 (e.g. the sleeve can be formed from a high-density polymer such as high-density or ultra- high-density polyethylene). In Fig. 11, like reference numerals are used to denote like parts (i.e. to those described in Figs. 1 to 10 but with 100 added thereto), unless described as being otherwise.

The sleeve 120 can be slidably installed over the outer surface of the composite section 110, and is sized so as to provide a snug fit against the exterior facing walls of the composite section 110. This snug fit enables the sleeve 120 to be secured in place against the exterior facing walls of the composite section 110 through a frictional resistance that is generated therebetween. As with the embodiments described above, a hole 122 through the sleeve 120 can be aligned with a pre- or post-formed hole 123 in a wall of the composite section 110. In use, the sleeve 120 can be installed prior to supply and distribution of the composite section 110 to a work site. This can improve the speed of installation of the composite section 110. For example, the sleeve 120 can be pre-aligned to the right location along the composite section 110 before it is supplied/distributed. Thus, the respective corresponding fastener-receiving holes of each of the sleeve 120 and composite section 110 can be aligned prior to arrival on a work site.

In use, the sleeve 120 can more effectively distribute a load applied from a fastener against the composite section 120. In this regard, a shank of a fastener can extend through the hole 122 of the sleeve and the pre- or post-formed hole 123 in the wall of the composite section 110. A head 124 of the fastener locates at an external surface of the sleeve adjacent to the hole 122. The sleeve 120 can thereby act in a manner similar to a washer, whilst also exhibiting the additional benefit of being formed from a high-density polymer, thereby being able to absorb and spread applied point/compression forces. For example, the sleeve 120 can absorb and spread the applied force that could otherwise crush the composite section or cause fracturing, cracking, shearing, etc. at and around the hole 123.

The sleeve 120 can, in use, work together with an insert block 20 that is inserted into the composite section 110. In this regard, the block 20 can be inserted to a location that generally aligns with the sleeve 120.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the insert block, system and sleeve.