IE52925B1 - Paving slabs - Google Patents

Description

This invention relates to paving slabs/blocks/stones. hereinafter referred to simply as ’’paving slabs”, of the type which are load-bearing and have recessed portions or voids extending downwardly from an upper face, the recessed portions or. voids being for holding growing medium in which primarily grass but other creeping vegetation for cover can be grown. Hereinafter the term grass will be used to include other creeping vegetation. Such paving slabs have been provided heretofore and when laid, over an area . of ground, are for use in all weathers for supporting self10 propelled or manually-propelled vehicles when parked thereon or driven thereacross without the ground subsiding or becoming uneven through that use.,After a period of time, the grass creeps over the slabs to give the appearance of a grassed area: a more pleasing appearance than simply an area of the material from which the slabs are formed. A disadvantage of existing paving slabs is that, when laid, the growing areas of the slabs consolidate to a level below top faces of the slabs thereby forming islands, for example of concrete, which protrude above the level of the grass and causes an uneven surface on which pedestrians can stumble, and free-movement of wheels of perambulators, baby carriages, invalid chairs or bicycles is hindered.

It is an object of the present invention to obviate or mitigate this disadvantage by providing a paving slab in which the growing areas have been minimised conductive to maximised cover creeping potential of the grass growing therein.

According to the present invention, a paving slab for use with others of its kind fn creating paved areas with each slab has recessed portions for containing a growing medium in which vegetation can be -grown and allowed to creep over the remainder of the slab, wherein each slab has two major faces in one of which the recessed portions are provided formed of a network of open-topped channels in which a series of drainage holes extend through the remaining depth of the slab to the other face, the channels at their open tops forming thereamong a plurality of lands with the open tops of the channels being narrow relative to said lands.

Preferably, the total surface area of the open tops of the channels amounts to approximately one fifth of the total surface area of the slab.

Preferably also, a plurality of similarly shaped recesses are provided in the other face with the recesses having sloping walls, and all or some of the drainage holes impinging on the recesses whereby to cause, in use, condensation from the ground condensing on the walls to run theredown to said drainage holes to serve to irrigate, through· the root formation, any vegetation growing in said channels.

Preferably further, the slab is rectangular and the network of channels is symmetrical about both transverse and longitudinal median axes.

Embodiments of the present invention will now be described, J»y way of example, with reference to the accompanying drawings, in which:Figs. 1 and 2 are top and underneath plan views respectively of a paving slab according to the first embodiment of the present invention; Figs. 3 and 4 are top and underneath plan views respectively of a paying slab according to the second embodiment of the present invention; Fig. 5 is a cross-sect ional view on the line V-V of Fig . l; Fig. 6 is a cross-sectional view on the line VI-VI of Fig 1; Fig. 7 is a cross-sectional view on the line VII-VII of Fig. 1; Fig. 8 is a cross-sectional view on the line VIII-VIII of Fig. 1; Fig. 9 is a cross-sect ional view on the line IX-IX of Fig 1; and Fig. 10 is a cross-sectional view on the line χ-χ of Fig. 3.

Referring to·the drawings, a paving slab of both embodiments has two major faces, one intended to be 5 the upper face 10 and the other the under face 11, both of which are rectangular, particularly square as shown.

The upper face 10 (Figs. 1 or 3) has a network of opentopped channels 12 provided thereacross, the channels 12 being symmetrically arranged about both transverse and jq longitudinal median axes. The network is formed from two sides of equi-spaced parallel channels 12 angularly extending between opposite lateral sides of the slab, the two series being mirror-images of each other. Diamond or halfdiamond shaped lands or islands 14 are formed by the j5 channels 12. The total surface area of the open tops of the channels amounts to approximately one fifth of the total surface area of the slab.

A plurality of similarly-shaped recesses 13 are provided in the under face 11, arranged in two series as shown in 20 Figs. 2 or 4. Each recess 13 (Figs. 2, 4, 6 and 7) is of shape complementary to a pyramid having a diamond-shaped base.

Each side of a slab has lugs 15 extending outwardly therefrom as shown. The lugs 15 are only part of the depth of a slab and are mocated as an extension of the' lower part of the slab.

In the first embodiment, (Figs. 1, 2 and 5) drainage holes 16 are provided at the intersections of the channels 11 and are in the form of bores through the rest of the slab to the undersurface 11. As can be seen from Fig. 2 there are three parallel rows of holes 16, the bores of the flanking rows impinge upon the recesses 13.

A plurality of locking or position-stabalising pins 17 are provided of, for example conical shape, to be driven into the ground through two or more drainage holes 16 as desired in an inverted attitude to prevent the slab from movement after being laid on prepared level ground.

In the second embodiment (Figs. 3, 4 and 10) draingage holes 18 are provided at certain elongate parts of the channels 12 and are in the form of slots through the rest of the slab to the under face 11. As can be seen from Fig. 4, the slots irapringe upon the recesses 13. A plurality of locking or stabilising pins 19 are provided having an elongate head and to be driven into the ground through two or more drainage holes 18 at one end thereof.

An area of ground is prepared and levelled and a plurality of slabs above-described of either or both embodiments are laid down thereon in juxtaposed positions with the lugs 15 of adjacent sides of two slabs abutting against each other to space the said sides apart a determined distance to create a further channel. After the slabs are laid and locking pins driven into the ground, growing medium is filled and compacted into the channels 12, drainage holes 16, 18 and channels formed between adjacent slabs and seeded. Grass grown therein gradually creeps over the diamond lands 14, and forms a cover therefor.

The upper face 10 of the lands 14 are flat and the channels 12 are narrow relative thereto. ' The consolidation of the growing medium in the channels· is minimal and the narrowness of the channels relative to the lands means that the only unevenness possible is that due to the depth of grass on top of the lands not sufficient for pedestrians to stumble over or to cause a bumpy ride for a wheeled vehicle.

The drainage holes are provided to remove excess water on top of the slabs to the sub-soil over which the slabs are laid, the bottom of the channels holding a proportion of the water for irrigation of the grass.

The recesses 13 can serve as keying means if the slabs are laid flat and no locking pins are to be used. Also condensation from the ground will condense on the walls and run theredown to the drainage holes and, in particularly dry weather, may serve to irrigate the root formation of the grass.

Slabs may be used to enhance or stabilise banks where the slabs are laid at angles on soil and sand bed or vertically as wall decoration both internally or externally. The locking pins are used to secure the slabs in position.

Claims (12)

1. CLAIMS:1. A paving slab for use with others of its kind in creating paved areas with each slab having recessed portions for containing a growing medium in which vegetation can be grown and allowed to creep over the remainder of the slab, wherein each slab has two major faces in one of which the recessed portions are provided formed of a network of open-topped channels in which a series of drainage holes extend through the remaining depth of the slab to the other face, the channels at their open tops forming thereamong a plurality of lands with the open tops of the channels being narrow relative to said lands.

2. A paving slab as claimed in Claim 1, wherein the total surface area of the open tops of the channels amounts to approximately one fifth of the total surface area of the slab.

3. A paving slab as claimed in Claim 1, wherein a plurality of siraiarly shaped recesses are provided in the other face with the recesses having sloping walls, and all or some of the drainage holes impinging on the recesses whereby to cause, in use, condensation from the ground condensing on the walls to run theredown to said drainage holes to serve to irrigate, through the root formation, any vegetation growing in said channels.

4. A paving slab as claimed in Claim 1, 2 or 3 wherein the slab is rectangular and the network of channels is symmetrical about both transverse and longitudinal median axes.

5. A paving slab as claimed in Claim 1, 2, 3 or 4 wherein the network is formed from two series of equi-spaced parallel channels angularly extending between opposite lateral sides of the slab, the two series being mirror images of each other about said median axes.

6. A paving slab as· claimed in any one of the preceding 5 Claims, wherein the drainage holes are provided at the inter-sections of the channels and are in the form of bores.

7. A paving slab as claimed in any one of Claims 1, 2, 3, 4 or 5, wherein the drainage holes are provided at 10 certain elongate parts of the channels and are in the form of slots.

8. A paving slab as claimed in Claims 3,4,5,6 or 7 wherein the recesses are arranged in two series.

9. A paving slab as claimed in any one of the preceding 15 Claims, wherein each side of a slab has lugs extending outwardly therefrom whereby with others of its kind being laid in juxtaposed positions, lugs of adjacent sides of two slabs are positioned to abut against each other and therefor space the said sides apart a determined 20 distance to create a further channel for holding growing medium.

10. A paving slab as claimed in any one of the preceding Claims, wherein two or more locking pins are provided ‘ to be drivep into the ground through drainage holes to 25 stabilise the slab.

11. A paving slab according to claim 1, substantially as hereinbefore described with reference to Figs. 1, 2, 5,6, 7, 8 or 9 of the accompanying drawings.

12. A paving slab according to claim 1, substantially as 30 hereinbefore described with reference to Figs. 3, 4, 6, 7, 8, 9 or 10 of the accompanying drawings.