Claims
- 1. A paving block having a structure comprising a block substrate consisting essentially of inorganic hydraulic cement and aggregate, and a solid top layer bonded to the upper surface of the block substrate, wherein the top layer is selected from a cured cement mortar layer containing fine aggregate firmly bonded to the substrate by its self-adhesive property and a tile layer firmly bonded to the substrate with adhesive cement mortar, the top layer being bonded to the block substrate with lateral margins of the substrate around the top layer of about 1 to 8 mm wide in horizontal distance from the peripheral edges of the substrate, the vertical distance from the surface of the top layer to the peripheral edge of the substrate being about 5 to 50 mm, the vertical distance between the peripheral edge and the bottom of the block substrate being in the range of about 3 cm to 20 cm, and the top layer being firmly bonded to the block substrate with squeeze-out deposits of cement mortar around the top layer and on the lateral margins; whereby a bonded interface between the top layer and the block substrate is substantially free of voids to increase bonding strength, and the void-free interface and squeeze-out deposits prevent the bonded interface from permeation of water.
- 2. The paving block according to claim 1, in which the lateral margins are about 1 to 5 mm in width, and the vertical distance between the top layer surface and the peripheral edge is about 5 to 30 mm.
- 3. The paving block according to claim 1, in which the block substrate comprises cement concrete containing coarse aggregate, and the upper surface of the block substrate is substantially covered with cured cement mortar containing fine aggregate.
- 4. The paving block according to claim 1, in which the upper surface of the block substrate has a depression for receiving the back of the top layer and the cement mortar, and the top layer is bonded into the depression.
- 5. The paving block according to claim 3, in which the upper surface of the block substrate has a depression for receiving the back of the top layer and the cement mortar, and the top layer is bonded into the depression.
- 6. The paving block according to claim 4, in which the depression is connected with slopes to the peripheries of the block substrate.
- 7. The paving block according to claim 5, in which the depression is connected with slopes to the peripheries of the block substrate.
- 8. The paving block according to claim 1, in which the squeeze-out deposits cover substantially all the lateral margins of the block substrate.
- 9. The paving block according to claim 3, in which the squeeze-out deposits cover substantially all the lateral margins of the block substrate.
- 10. The paving block according to claim 4, in which the squeeze-out deposits cover substantially all the lateral margins of the block substrate.
- 11. The paving block according to claim 5, in which the squeeze-out deposits cover substantially all the lateral margins of the block substrate.
- 12. The paving block according to claim 1, in which the adhesive cement mortar comprises a major amount of cement mortar and a minor amount of an organic adhesive polymer.
- 13. The paving block according to claim 1, in which the fine aggregate is of a size which passes through a 5 mm-square screen.
- 14. The paving block according to claim 4, in which the fine aggregate is of a size which passes through a 5 mm-square screen and the coarse aggregate is of a size which remains on a 5 mm-square screen.
Priority Claims (3)
| Number |
Date |
Country |
Kind |
| 62-175450 |
Jul 1987 |
JPX |
|
| 62-176623 |
Jul 1987 |
JPX |
|
| 62-176624 |
Jul 1987 |
JPX |
|
SUMMARY OF THE INVENTION
This is a division of application Ser. No. 07/360,922 filed Mar. 14, 1989, now U.S. Pat. No. 4,995,932.
1. Technical Field
This invention relates to a novel paving block to be installed on the grounds such as streets and floors, and to a method for production of the paving blocks.
2. Background Art
The plane configurations of conventional paving blocks have a variety of shapes such as rectangles, squares, triangles, other polygons, circles, oval, and other shapes. The peripheral side lines of the block can be straight, a curved line, a wave-like line or a combination thereof, as far as the blocks can be joined at an interval of a few millimeters when they are installed. The same plane configurations as those conventional blocks are employed in the present paving blocks.
A perspective view of a conventional paving block of rectangular parallelepiped is illustrated in FIG. 9, wherein a ceramic tile is bonded onto a cement concrete block having the same plane dimensions as the tile. Such conventional tile-bonded blocks have been produced by (1) placing a tile upside-down on the bottom of a casting mold and then casting concrete mortar thereon, or (2) casting concrete mortar into the mold and placing a tile thereon (e.g. Japanese Laid-open Patent Application No. 61-142202). According to the above-mentioned method (1), some dissolved components of concrete mortar flow down and deposit on the tile surface to form efflorescence. According to the method (2), lots of voids remain or are formed at the interface between the tile and block, which largely deteriorate the bonding strength between them. Moreover, durability is also decreased because water such as rain often permeates into the bonded interface through the voids.
Incidentally, a tile-bonded panel is known for walls composed of a multiplicity of tiles bonded onto a substrate board. In such tile panels, large bonding strength of tile is not especially needed because a large external force is not pressed on such wall panels, and also permeation of water is prevented because joint intervals of the tiles on the substrate board are filled with jointing paste. Thus, such tile-bonded panels for walls should be clearly distinguished from tile-bonded paving blocks.
The paving blocks are installed on the grounds such as streets at an interval of about 2 to 5 mm. The joint intervals of blocks thus installed are filled with sand (not with jointing paste).
The paving blocks installed on the grounds such as streets receive a variety of heavy loads from cars or the like. As a result, the blocks move to each other by complicated forces applied thereto and are often inclined together, whereby the shoulder portions of adjacent blocks collide with each other and break off.
The main object of the present invention is to solve the above-mentioned breaking or fracture problems and to provide novel paving blocks wherein the fracture of the shoulder portions is substantially eliminated.
There is thus provided, according to the present invention, a paving block having a structure comprising a block substrate consisting essentially of inorganic hydraulic cement and aggregate, and a top solid layer bonded to the upper surface of the block substrate: characterized in that the top layer is selected from a cured cement mortar layer firmly bonded to the substrate by its self-adhesive property and a tile-like layer firmly bonded to the substrate with cured cement mortar; the top layer is bonded to the block substrate with lateral margins of the substrate around the top layer of about 1 to 8 mm wide in horizontal distance from the peripheral edges of the substrate; and the vertical distance from the surface of the top layer to the peripheral edge of the substrate is about 5 to 50 mm.
It is preferred that the top solid layer mentioned above be firmly bonded to the block substrate with squeeze-out deposits of cured cement mortar around the top layer, whereby the bonding layer of cement mortar is substantially free of voids to increase bonding strength and to prevent the bonded interface from permeation of water.
There is also provided, according to the present invention, a method for producing a paving block comprising a block substrate and a tile-like top layer bonded to the upper surface of the block substrate, with lateral margins of about 1 to 8 mm wide in horizontal distance from the peripheral edges of the substrate and with vertical distance of about 5-50 mm from the surface of the top layer to the peripheral edge of the substrate; which method comprises
US Referenced Citations (7)
Divisions (1)
|
Number |
Date |
Country |
| Parent |
360922 |
Mar 1989 |
|
Patent Grant
5051023
