Paving slab having spot glued blocks

Abstract

A concrete paving slab formed of a number of individual spaced blocks connected together by drops of flexible synthetic resin adhesive. The adhesive drops are normally located midway between the top and bottom of the blocks and extend between the sides of the blocks. Recesses may be formed in the sides of the blocks, extending from the top part way down the sides, with the adhesive drops extending between the bottoms of the recesses, and cables may be laid in the joints and adhered to the adhesive. The composite slab can be handled and laid as a unit, and the joints filled with sand or mortar.

Description

This invention relates to a slab, made out of a plurality of individual blocks, for road surfaces.

Concrete slabs or blocks are manufactured and laid individually in a very wide variety of forms. The transportation, stacking, and laying of individual blocks consumes a considerable amount of time and is therefore costly. It has therefore been proposed to combine individual blocks into larger slabs at the manufacturer's plant. To this end, the individual blocks have in the past been placed on a plastic mat and then glued to this mat and to another mat placed on top of the blocks. This holds the blocks together so that they do not slide in relation to each other during transportation and laying. However, after the slabs have been laid to form a road surface, the top plastic mat must be removed. Apart from the fact that this involves a considerable amount of waste, these slabs are costly and require additional labour after they have been laid.

It is the purpose of the invention to produce a slab made up of a plurality of individual blocks, which is inexpensive to manufacture, has the necessary strength for transporting, storing, and laying, and in which the elements holding the slab together do not have to be removed after laying. The slab of the invention may be used for road surfaces, embankments, or for other appropriate paving applications.

According to the invention, this purpose is accomplished by forming the slab of individual blocks and by spot-connecting the individual blocks together with an adhesive, preferably a synthetic resin adhesive. The slabs are produced by laying the individual blocks in the desired arrangement and then joining them together with individual drops of synthetic resin. These drops of resin may be applied automatically in a single operation.

In order to improve the adhesion of the synthetic resin to the blocks, the side walls of the blocks may be provided, at specific intervals, with recesses located at right angles to the plane of the slab, the said recesses preferably extending over only a part of the height of each block.

If large slabs are to be produced, or if the slabs are made up of very heavy individual blocks, it is desirable to lay cables in the longitudinal and transverse joints in the slab formed by the blocks, the said cables being glued in place with synthetic resin. The said cables may be of plastic or steel.

The slabs, made up according to the invention out of individual blocks, are not only easier to transport and lay, but also have the advantage of being held together more firmly after they have been laid.

The invention is described hereinafter in greater detail, with the aid of the examples of embodiment illustrated in the drawing,

FIG. 1 is a plan view of a slab made up out a plurality of individual blocks;

FIG. 2 is a section along the line II--II in FIG. 1;

FIG. 3 is a cross section through a slab according to the invention, showing cables laid in the joints;

FIG. 4 is a plan view of another type of slab according to the invention;

FIG. 5 is a section along the line V--V in FIG. 4.

The slab illustrated in FIG. 1, and marked 1 as a whole, consists of 12 individual blocks 2 joined together by means of drops 5 of synthetic resin injected into longitudinal joints 3 and transverse joints 4. As shown in FIG. 2, these drops of resin join blocks 2 together at about half the height of each block.

Typically the slab 1 will range between 0.3 and 1.5 meters in length and in width and will contain between 6 and 40 joined blocks. The individual joined blocks are typically of the following dimensions:

length -- 8-25 cm.

width -- 8-25 cm.

thickness -- 4-12 cm.

weight -- 4-12 pounds.

The synthetic resin used to glue the blocks 2 together is flexible, so that it can yield eventually if the surface on which the blocks are laid should shift. Two kinds of synthetic resin which have been used successfully for this purpose are:

1. type Ipacollan D160 two component plastic glue, produced by Isar-Rakoll Chemie Gmbht, of Munich, West Germany,

2. type Bostik 33 two component plastic glue, produced by Bostik Gmbht, of Oberursel, West Germany

The location of the synthetic resin can be at the top or bottom of the blocks or half way between the top and bottom as shown. If the synthetic resin drops are near the tops of the blocks, the mobility of the bottoms of the blocks will be at a maximum. Conversely, if the resin drops are at the bottoms of the blocks, the mobility of the tops of the blocks will be maximized. Therefore, the location of the synthetic resin drops will be chosen depending on the mobility of the surface on which the blocks are laid, but as shown, the synthetic resin drops will normally be located about half way up the height of the blocks.

The material from which the blocks 2 are made can be concrete, ceramic or plastic, but the normal and preferred material is concrete. The number and cross-sectional area of the synthetic resin drops is chosen so that the complete slab can be picked up by two of its edges, and subjected to normal handling, but so that the drops will yield after the blocks are laid and loaded (e.g. by traffic or by stationary items such as benches) if the ground is uneven beneath the blocks. The strength of the synthetic resin drop joints is chosen so that the drops will yield, and if necessary break, before the blocks 2 break.

If desired, additional or larger drops of synthetic resin can be used to connect corner and edge blocks in the slab 1 to adjacent blocks then are used for interior blocks (since corner blocks only have two sides connected to other blocks and edge blocks only have three such sides, while interior blocks are connected on all four sides to adjacent blocks). Thus, for example, the drops marked 5a in FIG. 1 (and the corresponding drops used for the other corner and edge blocks) may be made twice the size of the other drops 5. This will ensure that the joints which hold the corner and edge blocks in the slab are at least as strong as those for the interior blocks, to facilitate handling the slab.

Reference is next made to FIG. 3, which is a cross-section of the same slab 1 as that shown in FIG. 2, except that cables 6 have been laid in the transverse and longitudinal joints 3, 4. The cables 6 may be of plastic or steel; typically they are either nylon or steel coated with zinc. The cables 6 rest on and are glued to the drops 5 of synthetic resin and impart increased strength to the slab 1. This arrangement can be used when slabs of very large dimensions, or heavy individual blocks, are used, and it imparts additional strength to the joints between the blocks.

Reference is next made to FIGS. 4 and 5, which shows a slab 1' having individual blocks 7 separated by joints or spaces 3', 4'. The slab 1' is the same as the slab 1 except that the side edges of individual blocks 7 have arcuate recesses 8 running at right angles to the plane of the slab. These recesses extend from the top of slab 7 to about half the height thereof. The recesses 8 have several advantages. Firstly, they facilitate locating the resin drops 5' about half way up the height of the blocks, since the bottoms of the recesses act as supporting surfaces for the resin drops. Secondly, the bottoms of the recesses have a fairly large surface area which allows the resin drop 5' to stick better without increasing the thickness (i.e. the height) of the resin drops.

In addition, in FIGS. 4 and 5 it will be seen that the width of the top parts of the joints 3', 4' is greater than that of the bottom parts of these joints. This wider spacing between the blocks 7 is more attractive visually than a narrow spacing, but the narrower spacing between the bottoms of the joints reduces the distance which the resin drops must bridge, increasing the strength of the joints.

In the FIGS. 4 and 5 embodiment, cables 6 are shown glued to the drops of resin 5', as in the FIG. 3 embodiment, but it will be understood that the cables 6 will be used only when particularly high strength is required.

The slab of the invention may be used to pave road surfaces, embankments, or other appropriate surfaces, and will normally be laid in a bed of sand, mortar or concrete. After laying, the spaces between the blocks will usually be filled with sand or mortar. Should the supporting surface shift, the glue drops will yield or break before the blocks themselves break, so that although the mortar between the blocks may require replacement, the blocks themselves will remain intact.

Claims

What I claim is:

1. A paving slab comprising a plurality of individual blocks spaced apart from each other in a predetermined pattern, adjacent blocks of said slab having opposed side edges, said opposed side edges having opposed recesses therein, said recesses extending at right angles to the plane of said slab and extending from the tops of said blocks to locations above the bottoms of said blocks, said blocks being spot connected to each other by a flexible adhesive, said adhesive extending between the bottoms of opposed recesses.

2. A paving slab according to claim 1 wherein said adhesive is a synthetic resin.

3. A paving slab according to claim 1 and including cables laid in the spaces between said blocks, said cables being adhered to said adhesive.

4. A paving slab according to claim 1 and including a plurality of cables laid in the spaces between said blocks, said cables being of plastic or steel.

5. A paving slab according to claim 1 wherein said blocks are formed of concrete.

6. A paving slab according to claim 1 wherein said blocks are formed of concrete, said slab being of length between 0.3 and 1.5 meters and of width between 0.3 and 1.5 meters, said blocks being between 6 and 40 in number.

7. A paving slab comprising a plurality of individual blocks spaced apart from each other in a predetermined pattern, adjacent blocks of said slab having opposed side edges, each side edge having an upper portion and a lower portion, said upper and lower portions each extending at right angles to the plane of said slab, the spacing between opposed upper portions being greater than the spacing between opposed lower portions, each side edge also having a transverse connecting portion connecting said upper and lower portions of such side edge, said connecting portions of adjacent slabs being opposed, said blocks spot connected to each other by a flexible adhesive, said adhesive extending between said opposed transverse connecting portions.

8. A paving slab according to claim 7 wherein said upper portions of said opposed side edges of said blocks have opposed recesses therein, said recesses extending at right angles to the plane of said slab and extending from the top of said blocks to said transverse connecting portions, said transverse connecting portions thereby defining the bottoms of said recesses, said adhesive extending between the bottoms of opposed recesses.