Roofing tile and method for producing such a roofing tile

Abstract

A roofing tile composed of concrete material and a method for producing such a roofing tile. The concrete material contains a binder, a gravel, a light-weight aggregate, and added water. The roofing tile has at least one watercourse and a lateral interlocking joint having a covering fold and a water fold. The ratio of water to binder is less than 0.3, the light-weight aggregate is composed of a material that is hydrophobic and/or not hygroscopic, and the roofing tile has a density in the range of 1.6 g/cm.sup.3 to 1.9 g/cm.sup.3 after the hardening. The roofing tile has a thickness of 5 mm to 9 mm, preferably 7 mm to 8 mm, in the highly loaded regions, preferably in the region of the watercourse.

Claims

1. A roofing tile composed of a concrete material consisting essentially of a binder, a rock particle fraction, a lightweight aggregate, a pigment and added water, which has at least one watercourse and has lateral interlocking joint folds consisting of a covering fold on a first end of the roofing tile and a water fold on an opposite second end of the roofing tile, characterized in that the ratio of water to binder is less than 0.3, the lightweight aggregate consists of a material which is hydrophobic and/or nonhygroscopic, the roofing tile after curing has a density in the range from 1.6 g/cm.sup.3 to 1.9 g/cm.sup.3, where the roofing tile has a thickness of from 5 mm to 9 mm, in regions configured for being highly loaded in use, located between the first end and the second end, and the roofing tile has a total porosity above 25% and an open porosity of less than 10%.

2. The roofing tile as claimed in claim 1, characterized in that the roofing tile comprises from 1300 cm.sup.3 to 1700 cm.sup.3 of concrete material, where the roofing tile has a size at which from 9 to 11 roofing tiles/m.sup.2 of roof area can be laid.

3. The roofing tile as claimed in claim 1, characterized in that the roofing tile comprises from 1700 cm.sup.3 to 2250 cm.sup.3 of concrete material, where the roofing tile has a size at which from 7 to 9 roofing tiles/m.sup.2 of roof area can be laid.

4. The roofing tile as claimed in claim 1, characterized in that the roofing tile comprises from 2250 cm.sup.3 to 2750 cm.sup.3 of concrete material, where the roofing tile has a size at which from 5 to 7 roofing tiles/m.sup.2 of roof area can be laid.

5. The roofing tile as claimed in claim 1, characterized in that the lightweight aggregate comprises less than 5% by weight of water before mixing.

6. The roofing tile as claimed in claim 1, characterized in that the lightweight aggregate is selected from the group consisting of hollow glass spheres, expanded clay, pumice and mixtures thereof.

7. The roofing tile as claimed in claim 1, characterized in that the lightweight aggregate comprises uncrushed and/or coated and/or hydrophobicized expanded clay, hydrophobicized pumice and/or hollow glass spheres and/or a mixture thereof.

8. The roofing tile according to claim 1, characterized in that the binder comprises cement and microsilica.

9. The roofing tile as claimed in claim 1, characterized in that the binder is a mixture in which the constituents of the mixture are selected from the group consisting of portland cement, microsilica and plasticizers.

10. The roofing tile as claimed in claim 1, characterized in that the ratio of water to binder is 0.22-0.28.

11. The roofing tile as claimed in claim 10, characterized in that the ratio of water to binder is 0.25.

12. The roofing tile as claimed in claim 1, characterized in that the roofing tile after curing has a density of 1.8 g/cm.sup.3.

13. The roofing tile as claimed in claim 1, characterized in that the concrete material has a mixture moisture content of less than or equal to 11%.

14. The roofing tile as claimed in claim 1, characterized in that the roofing tile has a weight per unit area of less than or equal to 35 kg/m.sup.2.

15. The roofing tile as claimed in claim 14, characterized in that the roofing tile has a weight per unit area of less than or equal to 25 kg/m.sup.2.

16. The roofing tile according to claim 1, wherein said thickness is from 7 mm to 8 mm.

17. The roofing tile according to claim 1, wherein said highly loaded regions are in the region of the watercourse.

18. A process for producing a roofing tile as claimed in claim 1, which comprises the following steps: mixing the concrete material consisting essentially of binder, rock particle fraction, lightweight aggregate, pigment and added water; shaping the mixture by means of extrusion; and parting the shaped extrudate obtained to form sections and curing the sections, characterized in that the ratio of water to binder is less than 0.3, the lightweight aggregate consists of a material which is hydrophobic and/or nonhygroscopic, and the roofing tile after curing has a density in the range from 1.6 g/cm.sup.3 to 1.9 g/cm.sup.3 and has a thickness of from 5 mm to 9 mm, in the highly loaded regions.

19. The process according to claim 18, wherein said highly loaded regions are in the region of the watercourse.

20. The process according to claim 18, wherein said thickness is from 7 mm to 8 mm.

21. The process for producing a roofing tile as claimed in claim 20, characterized in that the roofing tile comprises from 1300 cm.sup.3 to 1700 cm.sup.3 of concrete material, where the roofing tile has a size at which from 9 to 11 roofing tiles/m.sup.2 can be laid.

22. The process for producing a roofing tile as claimed in claim 20, characterized in that the roofing tile comprises from 1700 cm.sup.3 to 2250 cm.sup.3 of concrete material, where the roofing tile has a size at which from 7 to 9 roofing tiles/m.sup.2 can be laid.

23. The process for producing a roofing tile as claimed in claim 20, characterized in that the roofing tile comprises from 2250 cm.sup.3 to 2750 cm.sup.3 of concrete material, where the roofing tile has a size at which from 5 to 7 roofing tiles/m.sup.2 can be laid.

Description

(1) One embodiment of a roofing tile according to the invention which has been produced using a concrete material according to one of the examples is shown by way of example in the figures.

(2) The figures show:

(3) FIG. 1 cross section along the longitudinal axis of a roofing tile according to the invention composed of concrete material and a conventional roofing tile for comparison

(4) FIG. 2 side view of roof covering formed from a roofing tile according to the invention and from a conventional roofing tile.

(5) FIG. 1 depicts, in each case in cross section, a roofing tile 1 according to the invention composed of concrete material and a conventional roofing tile 15.

(6) The roofing tile 1 according to the invention has an upper side 2 and an underside 3. In addition, the roofing tile 1 has a covering fold 5, a middle rise 6 and a water fold 7. A watercourse 8, 9 is in each case arranged between the covering fold 5 and the middle rise 6 and also between the middle rise 6 and the water fold 7. The watercourses 8, 9 serve to conduct away water in a controlled manner in the case of rain and at the same time form the highly loaded regions onto which the greatest tensile force is generated in the lower layer when force is applied to the upper side 2.

(7) Two covering fold ribs 10, 11 are arranged on the underside of the covering fold 5. These covering fold ribs 10, 11 are configured in such a way that they can engage in a water fold of a second roofing tile. The water fold 7 of the roofing tile 1 has a plurality of water fold ribs 12, 13, 14. These water fold ribs 12, 13, 14 are configured so that the covering fold ribs of a further roofing tile can be arranged in these water fold ribs 12, 13, 14. Since the geometry of the covering fold 5 and of the covering fold ribs 10, 11 and also the geometry of the water fold 7 and of the water fold ribs 12, 13, 14 are unchanged compared to conventional roofing tiles 15, the lighter roofing tiles 1 according to the invention composed of concrete material can be combined with conventional roofing tiles 15 and joined to form a roof covering as is depicted in FIG. 2.

(8) Such a roof covering 3 made up of a roofing tile 1 according to the invention and a conventional roofing tile 15 is shown in FIG. 2. Here, the covering fold ribs 10, 11 of the covering fold 5 of the roofing tile according to the invention are configured so that they can engage in a water fold 16 of a conventional roofing tile. In addition, it can clearly be seen from the geometry of the lateral fold of the conventional roofing tile and of the roofing tile according to the invention, as depicted in FIG. 2, that it is also possible to arrange the covering fold ribs 17, 18 of the covering fold 19 of the conventional roofing tile 15 in the water fold ribs 12, 13, 14 of the roofing tile 1 according to the invention.

(9) It is additionally apparent from a comparison of the conventional roofing tile 15 with the roofing tile 1 according to the invention that the roofing tile 1 according to the invention has overall a low product thickness despite an unchanged geometry of the lateral fold 5, 7. In particular, the highly loaded regions of the roofing tile 1, especially the watercourses 8, 9, are thinner than in the case of conventional roofing tiles.

(10) The invention is not restricted to one of the above-described embodiments, but can be modified in many ways.

(11) All features and advantages, including structural details, three-dimensional arrangements and process steps which can be derived from the claims, the description and the drawing can be relevant to the invention both on their own and in a variety of combinations.

LIST OF REFERENCE NUMERALS

(12) 1 Roofing tile 2 Upper side 3 Underside 4 Roof covering 5 Covering fold 6 Middle rise 7 Water fold 8 Watercourse 9 Watercourse 10 Covering fold rib 11 Covering fold rib 12 Water fold rib 13 Water fold rib 14 Water fold rib 15 Conventional roofing tile 16 Water fold 17 Covering fold rib 18 Covering fold rib 19 Covering fold