Modular slab and modular surface system

A removable modular slab for use in the construction industry includes upper, lower, and first and second opposing end surfaces, and a conduit extending from the upper surface to an end surface. The slab is abuttable with a second removable modular slab, having: (i) a conduit extending from the upper surface to an end surface, and/or (ii) a cavity extending from an end surface into the slab, whereby the conduits mate to form an elongate conduit through the two slabs. By access through apertures in each slab, a first joining structure is removably locatable to join the two slabs. Cavities may terminate within the second slab and only be accessible through the upper surface of the first slab. A modular surface system includes two such slabs and a joining structure to join the two slabs together.

BACKGROUND

The present invention relates to a slab for use in the construction industry, especially to a modular construction slab, to a modular surface system including such slabs, and to a method of joining construction slabs.

It is well known in the construction industry to use slabs, especially concrete or concrete-derivative slabs, as building components. Such slabs find use as flooring components for buildings, public highways and the like. When two or more such known slabs are connected together, it is typically with some kind of internal tie that runs through the interior length and/or width of the slabs.

The problem with a system incorporating such slabs and ties is that, once the slabs have been joined together by the internal ties, if any adjustment, rectification or replacement of a slab or tie is required, the only way to access the tie to disconnect the appropriate slabs is by destroying at least a part of the slab and or tie as is necessary. This is both costly and time consuming because any part that has been even partially destroyed will typically need to be replaced, thereby rendering the system unavailable for a period of time until the rectification work has been completed.

It would therefore be desirable to provide an improved slab for use in the construction industry, and an improved method of joining slabs, neither of which suffer from the aforementioned problems.

SUMMARY

Accordingly, in a first aspect, an exemplary embodiment provides a removable modular slab for use in the construction industry, and includes an upper surface, a lower surface opposed to the upper surface, first and second opposing end surfaces between and substantially normal to the upper and lower surfaces, and a conduit extending from an aperture in the upper surface to an aperture in an end surface. The slab is end-to-end abuttable with a second removable modular slab, the second slab having an upper surface, a lower surface opposed to the upper surface, and first and second opposing end surfaces between and substantially normal to the upper and lower surfaces. The second slab is provided with one or both of: (i) a conduit extending from an aperture in the upper surface thereof to an aperture in an end surface thereof, and (ii) a cavity extending from an aperture in an end surface into the second slab, whereby the conduit in the first-mentioned slab is mateable with the conduit in the second slab so as to form an elongate conduit through the ends of the two slabs, which is accessible through the apertures in the upper surfaces of each slab, and through which a first joining means is removably locatable to join the two slabs together. In an alternative exemplary embodiment, the conduit in the first-mentioned slab is mateable with the cavity in the second slab so as to form an elongate cavity through the ends of the two slabs, which terminates within the second slab and which is only accessible through the aperture in the upper surface of the first-mentioned slab, into which a second joining means is removably locatable to join the two slabs together.

The first aspect of the disclosure also provides a second removable modular slab for use in the construction industry with the aforementioned removable modular slab of the preceding paragraph, such second slab including an upper surface, a lower surface opposed to the upper surface, first and second opposing end surfaces between and substantially normal to the upper and lower surfaces, and a cavity extending from an aperture in an end surface thereof into the second slab. The second slab is end-to-end abuttable with the aforementioned slab, whereby the cavity is mateable with a conduit of the aforementioned slab so as to form an elongate cavity through the ends of the two slabs, which terminates within said second slab and which is only accessible through the aperture in the upper surface of the aforementioned slab, in which a second joining structure is removably locatable to join the two slabs together.

Provision of a removable modular slab of this type is advantageous because, firstly, the modular aspect means that the slabs have reproducible and predictable dimensions, and so can be more easily and accurately aligned. Secondly, the slabs can be rapidly installed, whether during initial installation or subsequent replacement, and readily adjusted with minimal disruption and cost. In this regard, the upper surface of the slab is preferably an exposed surface, i.e. it is readily accessible, as are the apertures therein.

Preferably at least one of the first and second opposing end surfaces of one slab is profiled such that a cooperative joint is formable with a profiled end surface of the other slab when the two slabs are abutted together.

Advantageously, the end surface profile of one slab includes a protrusion and the end surface profile of the other slab includes a corresponding concavity. Thus, when the end surface of one slab and the end surface of the other slab are brought into abutment, the surfaces and profile mate so as to form an intimate joint. Through this joint, the elongate conduit or elongate cavity may extend, and thus also the first or second joining structure for joining the two slabs.

Further advantageously, the protrusion and the concavity may be shaped such that the end surface of each (i.e. that surface which would lie flush with the remainder of the end surface of the slab if the protrusion were flattened or the concavity shrunk) is at an angle of 45° or less to the vertical, preferably less than 25°, further preferably less than 15° and most preferably in the range of from 1-5° to the vertical.

The end surface profile of one slab may extend along the length of the end surface of the slab, and correspondingly the other slab also. However, it is not essential that the mating surfaces have such an extent. Indeed, the end surface profile may extend only part-way along the length of the end surface of both slabs; the profile may be positioned towards the center of the width of the end surface of the slabs, or it may extend from one end of the end surface.

In another exemplary embodiment, a removable modular slab may have two identically profiled end surfaces, and as such will be referred to as a type-A slab. The other modular slab, against which a type-A slab is abuttable, may also have two identically profiled end surfaces, which are different from, but cooperable with, the type-A slab, and this other slab will be referred to as a type-B slab. A type-A slab may have, for example, two end surfaces that are each provided with a concavity, and a type-B slab may have, for example, two end surfaces that are each provided with a protrusion, the concavities and protrusions being of complementary and cooperative shape. With such type-A and type-B slabs, a row of multiple slabs following the pattern A-B-A-B-A-B-(etc.) may be provided.

In an exemplary alternative embodiment, a removable modular slab may have two differently profiled end surfaces, and as such will be referred to as a type-C slab. The profile of one of the end surfaces of a type-C slab may be cooperable with the profile of the other end surface, such that one type-C slab is abuttable against a further type-C slab. For example one of the end surfaces of a type-C slab may be provided with a concavity whilst the other end surface may be provided with a protrusion. With such type-C slabs, a row of multiple slabs following the pattern -C-C-C-C-C-(etc.) may be provided.

A removable modular slab as hereinbefore described may be pre-cast or pre-moulded from a construction material. Any suitable material known in the art may be used; however, concrete or a concrete-derivative material, such a glass-fibre reinforced concrete (GFRC) or glass-fibre reinforced plastic (GFRP). Other components may include rebar or a plastics material. Plastic may be preferred for its inherent strength, corrosion-resistance, and electrical current-resistance.

A modular slab may have one or more voids, such as longitudinal voids, provided within it, thereby reducing its weight, compared to a full-density slab, without compromising its strength. These voids may remain empty or may be filled with a lightweight filler material, such as an aerated/foamed rubber. Advantageously, this filler material may also absorb vibrations if and when the slab is subjected to vibrational forces.

Additionally, a modular slab may include one or more channels in its first surface, such as for drainage purposes and/or for accommodation of cables, such as electricity cables. Furthermore, longitudinal ducts may be provided alongside the one or more channels for accommodation of cables and/or into which surface water may drain. Moreover, the longitudinal ducts may be crossed by transverse ducts within the slab.

A second aspect of the disclosure provides a modular surface system for use in the construction industry, and includes two modular slabs, both having a conduit extending from an aperture in their upper surfaces to an aperture in their end surfaces, wherein the first joining structure is removably locatable through the elongate conduit.

In practice, any number of modular slabs may be joined together in this manner, and indeed may be joined linearly, to form an elongate surface, or multi-directionally to form a more expansive surface area.

Advantageously, the first joining structure may be removably locatable in the elongate conduit. Furthermore, the first joining structure may be adjustably locatable in the elongate conduit. In both cases, the ease of accessibility to the first joining structure, as a result of the configuration of the conduits in the slabs, enables adjustment, alignment and replacement of a modular slab within this modular surface system in a quick, easy and low cost manner.

In an exemplary embodiment, the elongate conduit is arcuate or parabolic; the conduit is open at both ends in the upper surfaces of two adjacent modular slabs and may arc between adjacent end surfaces of the slabs. Correspondingly, the first joining structure may be a curved, tensionable cable or tie, or a flexible bar connector. When a cable is located in the elongate conduit via the upper surfaces in two adjacent modular slabs, the lower part of the cable may be subjected to tensile forces whilst the upper part of the cable may be subjected to compressive forces. Thus when a force is applied to the cooperative joint between the two slabs, the distribution of forces within the cable retains the alignment of the slabs. In this way, the slabs act collectively as a monolithic structure.

The first joining structure may be fastenable and tensionable at the upper surfaces of each slab, providing easy access to the first joining structure in the event that realignment or replacement of one or more slabs is required.

The second aspect of the present disclosure also accordingly provides a modular surface system for use in the construction industry, and includes two modular slabs, one having a conduit extending from an aperture in its upper surface to an aperture in its end surface and one having a cavity extending from an aperture in its end surface into its body, as hereinbefore described, and a second joining structure to join the two slabs together, wherein the second joining structure is removably locatable in the elongate cavity.

Again, any number of modular slabs may be joined together in this manner, and indeed may be joined linearly, to form an elongate surface, or multi-directionally to form a more expansive surface area.

Advantageously, the second joining structure may be removably locatable in the elongate cavity. Furthermore, the second joining structure may be adjustably locatable in the elongate cavity. In both cases, the ease of accessibility to the second joining structure, as a result of the configuration of the mating conduit and cavity in the slabs, enables adjustment, alignment and replacement of a modular slab within this modular surface system in a quick, easy and low cost manner.

In one exemplary embodiment, the elongate cavity is arcuate, parabolic or linear; the cavity is open at one end only in the upper surface of one of the adjacent modular slabs and terminates in the body of the other slab. Correspondingly, the second joining structure may be a curved, tensionable cable or tie, or a flexible bar connector.

The second joining structure is preferably anchored at the terminal end of the elongate cavity within one slab and tensionable at the upper surface of the other slab, providing easy access to the second joining structure in the event that realignment or replacement of one or more slabs is required.

As described above, a modular slab may be of one of three types: type-A, type-B or type-C. A modular surface system may comprise both type-A and type-B cooperative modular slabs. Alternatively, however, the system may comprise just one type of slab: type-C.

In various embodiments, a modular surface system may be used widely in the construction industry. However, it also finds particular use as a railway or metro track support. Typically, a railway is constructed from a foundation or sub-grade material on top of which a layer of ballast is laid. The purpose of the ballast layer is to provide a level substrate for the sleepers to be laid upon, and then for the railways tracks themselves to be fastened to the sleepers. The problem with this construction is that the ballast layer and the sleepers are prone to degradation due to the elements, i.e., water, snow and ice can penetrate, leading to track misalignment. Realignment of such a track is often costly and time-consuming, and is often accompanied by significant delays to rail traffic, thereby reducing track availability and capacity.

Use of a modular surface system as a railway track support minimises these problems by replacing the sleepers with modular slabs. The railway track may be supportable on the first surfaces (typically the upper surfaces) of the modular slabs, which themselves may be laid directly onto an existing ballast layer as a foundation. Alternatively, the foundation may be in the form of recycled or hydraulically stabilised ballast, or it may simply be earth. The ballast layer would be mostly covered and protected from the elements by the slabs, and the improved joining structure between the slabs thereby creates a contiguous structure.

Alternatively, the metro track may be embedded into the first surface (typically the upper surface) of the slabs.

In practice, a plurality of modular slabs may be joined with a joining structure to form a monolithic railway/metro track support, without the need for additional concrete to provide strength, as a long-term solution and alternative to ballasted railway tracks. This may be particularly advantageous in tunnels, crossovers and switches, level crossings and in locations where poor ground conditions exist; also for light rail applications in urban areas (for example, an urban light railway) where rapid installation is essential to minimise disruption to traffic in the locality.

Of course, there are many other uses for the disclosed modular slab and modular surface system, including, without limitation, as flooring in a building, for a highway, in airports (such as for a runway) and at ports or freight terminals (to form the hardstanding). The disclosed modular slab and modular surface system may be utilized in non-horizontal (or at least, non-ground) applications, for example in the walls of retaining structures and for temporary or emergency structures.

A third aspect of the present disclosure provides a method of removably joining two construction slabs, each having an upper surface, a lower surface opposed to the upper surface, and first and second opposing end surfaces between and substantially normal to the upper and lower surfaces, and each having a conduit extending from an aperture in the upper surface thereof to an aperture in an end surface thereof. The method includes end-to-end abutting the two slabs, such that the conduit in one slab is mateable with the conduit in the other slab so as to form an elongate conduit through the ends of the two slabs, and removably locating a first joining structure through the elongate conduit such that each end of the first joining structure is accessible via the upper surface of each slab.

The third aspect of the present disclosure also provides a method of removably joining two construction slabs, each having an upper surface, a lower surface opposed to the upper surface, and first and second opposing end surfaces between and substantially normal to the upper and lower surfaces, one slab having a conduit extending from an aperture in the upper surface thereof to an aperture in an end surface thereof and the other slab having a cavity extending from an aperture in an end surface thereof into said slab. The method includes end-to-end abutting the two slabs, such that the conduit in one slab is mateable with the cavity in the other slab so as to form an elongate cavity through the ends of the two slabs, and removably locating a second joining structure through the elongate cavity which terminates within the other slab such that the second joining structure is only accessible via the upper surface of the first slab.

This method of joining is applicable with the modular slabs according to the first aspect of the disclosure, and in the modular surface system according to the second aspect of the disclosure. However, it is also applicable to other slabs which facilitate access to a joining structure through their upper surfaces, which in the case of retaining structures or emergency structures, may be outer vertical or substantially vertical surfaces.

The method may further include the steps of subsequently anchoring/fastening and tensioning the joining structure, which avoids the need to use jointing materials to harden or cure before the slab construction is brought into use.

The foregoing summary does not limit the invention, which is defined by the attached claims. Similarly, neither the Title nor the Abstract is to be taken as limiting in any way the scope of the claimed invention.

DETAILED DESCRIPTION

FIGS. 1 and 2show a modular slab10comprising a first surface, in the form of an upper surface11, a second surface, in the form of a lower surface12and two opposing end surfaces13. The slab10is elongate in the direction between the two end surfaces13. The end surfaces13of the slab10are each profiled to form a concavity16. This profile extends part-way along the length of, and is centred on, the end surface13. Located within the concavity16are four apertures14, which correspond to a further four apertures15located in the upper surface11of the slab10, adjacent to the end surface13. A conduit19(shown in dotted outline) extends between each pair of apertures, joining them.

Slab10also includes longitudinal voids17(shown in dotted outline) which may be filled with foamed rubber to both reduce the overall weight of slab10(compared to a similar slab formed without voids) and to dampen any vibrations through it without compromising its strength. Additionally, a central elongate channel18is provided along the longitudinal axis of the slab, along with drainage outlets18a, for drainage of surface water which may otherwise stagnate on the slab's upper surface11. On either side of channel18within the body of slab10, two longitudinal ducts18bmay be provided, along with optional transverse ducts18c.

FIGS. 3 and 4show a modular slab20similar to slab10shown inFIGS. 1 and 2, in that slab20includes a first surface, in the form of an upper surface21, a second surface, in the form of a lower surface22and two opposing end surfaces23. The slab20is elongate in the direction between the two end surfaces23. Slab20also includes longitudinal voids27(shown in dotted outline) which may be filled with foamed rubber to both reduce the overall weight of slab20(compared to a similar slab formed without voids) and to dampen any vibrations through it without compromising its strength. Additionally, a central elongate channel28is provided along the longitudinal axis of the slab, along with drainage outlets28a, for drainage of surface water which may otherwise stagnate on the slab's upper surface21. On either side of channel28within the body of slab20, two longitudinal ducts28bmay be provided, along with optional transverse ducts28c.

Slab20differs from slab10in that the end surfaces23of the slab20are each profiled to form a protrusion26. This profile extends part-way along the length of, and is centred on, the end surface23. Located on the protrusion26are four apertures24, which correspond to a further four apertures25located in the upper surface21of the slab20, adjacent to the end surface23. A conduit29(shown in dotted outline) extends between each pair of apertures, joining them.

For the avoidance of doubt, although only four conduits have been described with reference to slabs10and20, any number of conduits as is deemed necessary to secure two slabs together may be provided. The conduits may be of varying diameter and may be dissimilar to one another, dependent upon the degree of tension to be applied to the joining structure (e.g., tensionable cable).

FIG. 5shows two modular slabs10,20, and in particular the manner in which the two slabs are end-to-end abuttable. Slab10is as shown inFIGS. 1 and 2, whilst slab20is as shown inFIGS. 3 and 4. When slabs10,20are brought into end-to-end contact, protrusion26fits snugly into concavity16to form an intimate joint. In this joint, the conduits (not shown) that extend between the apertures14,24in the end surfaces13,23and the apertures15,25in the upper surfaces11,21of each slab10,20meet and are aligned such that an elongate conduit (not shown), which extends from the upper surface11of slab10to the upper surface21of slab20, is formed.

FIG. 6illustrates how a number of slabs10are joined to a number of slabs20to form a continuous monolithic surface. It is clear that should a slab10need to be removed from the system, it may be upwardly removed simply and in a nondestructive manner. The slabs10,20may be a pair of type-A, having identically profiled protrusions on their end surfaces, and type-B, having identically profiled concavities on their end surfaces, slabs. The advantage with this configuration is that, should it be necessary, a type-B slab can be lifted outwardly of the system and away from its adjacent type-A slabs. Alternatively, the slabs10,20may both be type-C slabs, having a protrusion formed on one end surface and a concavity formed on the opposing end surface. Furthermore, although the slabs10,20have been described as having only two of their end surfaces profiled, one or both of their long-edge surfaces may also be profiled to enable joints to be formed at all four edges.

Turning now toFIG. 7, this shows an alternative slab30, which is quite similar to slabs10,20, in that it comprises a first surface, in the form of an upper surface31, a second surface, in the form of a lower surface32and two opposing end surfaces33a,33b, between and substantially normal to the first and second surfaces. The slab30is elongate in the direction between the two end surfaces33a,33b. The end surface33aof the slab30is however profiled to form a protrusion36a(rather than a concavity). This profile extends along the full length of the end surface33a. End surface33bis profiled to form a concavity36b, which also extends along the full length of surface33b. Located on end surface33aof the protrusion36aare four apertures34, which correspond to a further four apertures35located in the upper surface31of the slab30, adjacent to the end surface33a. A conduit39(shown in dotted outline) extends between each pair of apertures, joining them.

Furthermore, slab30comprises a central elongate channel38along the longitudinal axis of the slab30, along with drainage outlets38a. Optionally transverse ducts38cmay be provided within the body slab30also. Slab30may be described as a type-C slab, having a protrusion formed on one end surface and a concavity formed on the opposing end surface.

When slab30is end-to-end abutted with a further slab, this further slab may be profiled to form a concavity, which extends along the full length of its end surface, and which is provided with correspondingly located apertures and conduits, thereby forming a -C-C-C-C-(etc.) type modular system, as is illustrated inFIG. 8.

FIG. 9shows a modular surface system40comprising, in this instance, two slabs10,20of the type herein described. Slabs10,20are end-to-end abutted to form a cooperative joint43, such that the individual conduits19,29in each slab meet and join to form an elongate conduit44, which extends between the two slabs10,20. Through conduit44a first joining structure42, in the form of a flexible wire cable which can be made to follow an arcuate path, is located. Each end of the joining structure42is provided with fastening and tensioning means45to lock the slabs10,20into position and to provide strength to the joint43.

Cooperative joint43is profiled such that the end surfaces13,23that form the concavity16and protrusion26respectively lie at an angle of 5-10° to the vertical (as is shown by the angle8annotated on the drawing). By providing the surfaces of the joint in this manner, the two slabs10,20are easier to align when laying the system40.

Any two or more slabs10,20may be joined according to the following:

prepare a surface, for example a sub-soil layer (not shown) and a top-ballast layer (not shown), by levelling it;

lay two slabs10,20in end-to-end abutment such that their profiled surfaces13,23meet and a plurality of elongate conduits44are formed between the two;

locate a joining structure, for example a cable42, in each elongate conduit44by feeding it through an aperture15in the upper surface11of slab10until it appears through the corresponding aperture25in the upper surface21of slab20; and

affix a fastening and tensioning structure45to each accessible end of each cable42to lock them into position and subsequently apply tension to them, which will tighten the joint43between the two slabs10,20.

This method is equally applicable to the laying and joining of two or more slabs30.

FIG. 10shows the slab10ofFIGS. 1 and 2in use as a railway track support. Slab10is laid on a foundation surface (not shown) and is provided with a railway track50and a fixing51for fixing the track50to the upper surface11of slab10. Instead of using GFRP concrete, a reinforcement rod52is provided within the body of slab10, in this instance adjacent to the lower surface12of the slab and extending up the side of the slab. Rod52may continue around ducts18band adjacent the upper surface11of the slab to form a reinforcement loop. As an additional safety feature, slab10includes an optional raised portion54, which extends longitudinally down each side of the upper surface11, and is located outboard of track50. Should a train travelling on tracks50become de-railed, raised portion54helps prevent the train from toppling over and coming off the slab track, thereby further increasing rail safety.

FIG. 11also shows the slab10ofFIGS. 1 and 2in use as a railway support. Slab10is again provided with a railway track50and a fixing51, however the upper surface11has been modified to include a raised-profile portion101—the center of the slab is of greater depth when viewed in section compared to the outer edges of the slab, with tapering of the depth from the centre to the outer edges. Furthermore, upper surface11is provided with two longitudinal recesses102which accommodate the track50and fixing51components. In this way, the track50is effectively embedded in the slab10, which may be especially useful when a railway track needs to be lowered to increase the clearance when laid in a tunnel or under a bridge, or at level crossings and locomotive maintenance yards, where it allows for maintenance work to take place as a result of the access possible with normal road vehicles.

FIG. 12illustrates a network60of slabs which are joined to form a more expansive surface area than would be achieved by merely joining slabs end-to-end. InFIG. 12there are provided different types of slabs, having profiles formed on end surfaces and/or side surfaces as necessary to enable connections to be made to adjacent slabs as appropriate. In particular,FIG. 12shows slabs61having profiles in the form of a pair of protrusions62on one end surface63and one side surface64, slab65having profiles in the form of a pair of concavities66formed in both end surfaces67and one side surface, and slab68having profiles in the form of a pair of protrusions69formed in both end surfaces70and both side surfaces.

Apertures71and conduits72are appropriately located such that elongate conduits72are formed when the different slabs are abutted, enabling joining of said slabs in two directions (i.e. in an x-direction and in a y-direction) thereby formed a mosaic of slabs. In the case of a network60, the slabs may be square-shaped rather than elongate.

FIGS. 13 and 14show a modular slab10′ which is very similar to modular slab10shown inFIGS. 1 and 2; the similarity is such that like features have been provided with like reference numerals inFIGS. 13 and 14, however denoted with a prime symbol ('). The difference between slab10′ and slab10is in the end profile of the slabs resulting from the profile of channel18′ in slab10′ and channel18in slab10.FIGS. 13 and 14clearly show a taller height profile along both longitudinal edges defining channel18′, through which longitudinal ducts18b′ are provided.

FIG. 15shows a modular surface system40′ which is an alternative to modular surface system40shown inFIG. 9. Like features have been provided with like reference numerals inFIG. 15, however denoted with a prime (′) or double prime (″) symbol. The main difference between the systems shown inFIGS. 9 and 15is in the second joining means42′ and corresponding alternative form of slab10″.

Slab10″ comprises a cavity80which extends from an aperture (not shown) in end surface13″ into the body of slab10″ and is provided therein with a tension-fixing anchoring ferrule81. Slabs10″,20are end-to-end abutted to form a cooperative joint43′, such that the cavity80and conduit29in each slab meet and join to form an elongate cavity82, which extends between the two slabs10″,20. Into cavity82a second joining structure42′, in the form of a flexible wire cable or GFRP curved bar which can be made to follow an arcuate path, is located. The first end of cable/curved bar42′ screw-threads into ferrule81to anchor the cable into position, whilst the other end of the cable/curved bar42′ is provided with fastening and tensioning means45′ to lock the slabs10,20into position and to provide strength to the joint43′.

Cooperative joint43′ is again profiled such that the end surfaces13,23that form the concavity16″ and protrusion26respectively lie at an angle of 5-10° to the vertical (as is shown by the angle e annotated on the drawing). By providing the surfaces of the joint in this manner, the two slabs10″,20are easier to align when laying the system40′.

FIG. 16show a modular slab10′″ which is very similar to modular slab10shown inFIG. 11; the similarity is such that like features have been provided with like reference numerals inFIG. 16, however denoted with a triple prime symbol (′″). The difference between slab10′″ and slab10is in the end profile of the slabs.FIG. 16shows slab10′″ in use as a metro slab for city light rail systems. Slab10′″ is again provided with a rail/fixing component50′″ and a fixing51′″, however the upper surface11″ has been modified to include two outer raised-profile portions101′—the edges of the slab10′″ are of greater depth when viewed in section compared to the center of the slab, which allows for the laying (in the shallower area) of road surfacing materials (not shown). Furthermore, upper surface11′″ is provided with two longitudinal recesses102′″ which accommodate the track50′″ and fixing51′″ components. In this way, the track50′″ is effectively embedded in the slab10′″, which may be especially useful as a metro track located in a highway or city streets. The modular slab10′″ can accommodate numerous ducts17′″ for cables associated with a metro system and recesses102′ that are provided with drainage outlets103,104,105to allow for the collection, escape and drainage of surface and sub-surface collected water.

FIG. 17shows a modular slab170comprising a first surface, in the form of an upper surface171, a second surface, in the form of a lower surface172and two opposing end surfaces173(only one of which is shown). The slab170is elongate in the direction between the two end surfaces173. The end surface173of the slab170shown inFIG. 17is profiled to form a concavity177. This profile extends part-way along the length of, and is centered on, the end surface173. Located within the concavity177are two apertures174, which correspond to a further two apertures175located in the upper surface171of the slab170, adjacent to the end surface173. A conduit179(shown in dotted outline) extends between each pair of apertures, joining them. Also located within the concavity177are two cavities176awithin each a ferrule176bis provided.

Slab170also comprises a central elongate channel178, which is provided along the longitudinal axis of the slab, along with drainage outlets178a, for drainage of surface water which may otherwise stagnate on the slab's upper surface171. On either side of channel178within the body of slab170, two longitudinal ducts178bmay be provided, along with optional transverse ducts178c.

FIG. 18shows a modular slab180similar to slab170shown inFIG. 17, in that slab180comprises a first surface, in the form of an upper surface181, a second surface, in the form of a lower surface182and two opposing end surfaces183(only one of which is shown). The slab180is elongate in the direction between the two end surfaces183. Slab180also comprises a central elongate channel188, which is provided along the longitudinal axis of the slab, along with drainage outlets188a, for drainage of surface water which may otherwise stagnate on the slab's upper surface181. On either side of channel188within the body of slab180, two longitudinal ducts188bmay be provided, along with optional transverse ducts188c.

Slab180differs from slab170in that the end surface183of slab180is profiled to form a protrusion187. This profile extends part-way along the length of, and is centered on, the end surface183. Located on the protrusion187are two apertures184, which correspond to a further two apertures185located in the upper surface181of the slab180, adjacent to the end surface183. A conduit189(shown in dotted outline) extends between each pair of apertures, joining them. Also located on the protrusion187are two cavities186awithin each a ferrule186bis provided.

FIG. 19shows a modular slab170′ which is very similar to modular slab170shown inFIG. 17; the similarity is such that only the differences will be described. As shown, slab170′ further includes (i) an aperture174in end surface173outside of concavity177, which is joined to an aperture175in the upper surface171by a conduit179which extends between them, and (ii) a cavity176awithin which a ferrule176bis provided.

Similarly,FIG. 20shows a modular slab180′ which is very similar to modular slab180shown inFIG. 18; the similarity is such that only the differences will be described. As shown, slab180′ further includes (i) an aperture184in end surface183outside of protrusion187, which is joined to an aperture185in the upper surface181by a conduit189which extends between them, and (ii) a cavity186awithin which a ferrule186bis provided.

Finally,FIG. 21shows a modular slab190in use as a railway track support. Slab190is laid on an existing railway ballast surface252and is provided with a railway track250and a fixing251for fixing the track250to the upper surface191of slab190. Slab190comprises a first surface, in the form of an upper surface191, a second surface, in the form of a lower surface192and two opposing end surfaces193(only one of which is shown). The slab190is elongate in the direction between the two end surfaces193. The end surface193of the slab190shown inFIG. 21is profiled to form a concavity/protrusion197. This profile extends part-way along the length of, and is centered on, the end surface193. Located within the concavity/on the protrusion197are three apertures194, which correspond to a further three apertures195located in the upper surface191of the slab190, adjacent to the end surface193. A conduit199(shown in dotted outline) extends between each pair of apertures, joining them. Also located outboard of the concavity/protrusion197are two cavities196a, one on each side of the concavity/protrusion197, within each a ferrule196bis provided.

Slab190also comprises a central elongate channel (not shown), which is provided along the longitudinal axis of the slab, along with drainage outlets (not shown), for drainage of surface water which may otherwise stagnate on the slab's upper surface191. On either side of the channel within the body of slab190, two longitudinal ducts198bare provided.