Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04D—ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS
  • E04D1/00—Roof covering by making use of tiles, slates, shingles, or other small roofing elements
  • E04D1/02—Grooved or vaulted roofing elements
  • E04D1/04—Grooved or vaulted roofing elements of ceramics, glass or concrete, with or without reinforcement

Definitions

• the present invention relates to an improved clay tile materials, in particular roof tiles, which have practically no water absorption capacity, but which can, however, be produced in a conventional manner - with regard to firing temperatures, firing time or setting in the kiln.
• Clay roof tiles are exposed to the weather after installation. In very unfavorable cases, water penetrating the surface can get through to the bottom. In any case, excessive water absorption will endanger the frost resistance. Relatively coarse, unreacted CaO grains that frequently occur in bricks can lead to blasting off on the brick surface through reaction with water and CO 2 .
• US-A-3 035 937 describes a process for the manufacture of a glazed ceramic article, e.g. Brick or tiles described, the glaze being created by applying two glass-like slurries and then baking.
• the first slip contains a dye in addition to the glaze-forming material, while the second slip contains free silica and titanates in addition to the glaze-forming material.
• the present invention now relates to improved clay brick materials, in particular roof tiles, which consist essentially of conventional fired brick clays and a waterproof coating, and which are characterized in that a glass-like intermediate layer and then an engobe layer is located on the brick clay.
• the invention further relates to a method for producing such materials.
• the water absorption of clay roof tiles is practically prevented without having to change anything in terms of temperature, burning time and setting in the oven.
• the brick materials according to the invention can generally be produced as follows:
• a very thin glaze layer (glass-like intermediate layer) is applied.
• an engobe is applied using the same application process, which can consist of the clays used to manufacture the brick or suitable engobetones, each with a certain proportion of binding frit.
• the bricks are then fired in the usual way, being placed so close that they touch each other at least at certain points.
• the baking temperatures are - depending on the raw material - between 900 and 1100 ° C, preferably between 950 and 1050 ° C.
• the inferiority of such clays can consist, for example, of practically frequently occurring contents of natural lime inclusions, which cannot be comminuted adequately when the brick mass is processed for reasons of cost. These lime inclusions are converted to CaO in the fire and, when the bricks are used, can lead to blasting off the brick surface through hydration and recarbonation.
• the engobe's drying and burning shrinkage behavior must be closely matched to the shrinkage of the brick.
• the sintering behavior must be controlled via the composition of the engobe in such a way that sufficient hardness is achieved without sticking between the bricks under the pressure of the bricks which occurs in practice.
• the roof tile mass contained illite, kaolinite and quartz as the main mineral constituents and, to a lesser extent, feldspar and calcite as minor constituents.
• the coefficient of thermal expansion of the mass fired at 980 ° C and 48 hours burning time was 55. 10- 7 ° C -1 .
• the focal vibration was 6%.
• the glassy intermediate layer consisted of 90% frit with the following composition and 10% slurried kaolin:
• the coefficient of thermal expansion of the frit was 49. 10- 7 ° C -1 .
• the engobe consisted of 75% clay FTRA (Fuchs clay pit) and 25% of a frit with the following composition:
• the FTRA clay has a coefficient of thermal expansion of 49 - 10- 7 ° C -1 under the firing conditions mentioned above.
• the frit has a coefficient of thermal expansion of 77 - 10- 7 ° C- 1 . In terms of calculation, this results in a thermal expansion coefficient of 55 for the engobe, which corresponds exactly to that of the brick mass.
• the fire shrinkage of the engobe is 6%.
• the liter weight of the slip for the glass-like intermediate layer was set at 1,550 g / l.
• the fineness corresponded to 1% by weight of residue on the 10,000 mesh screen.
• the application thickness was 3 g / 100 cm 2 .
• the liter weight of the engobe slip was 1300 g / l.
• the fineness corresponded to 6% by weight residue on the 16900 mesh screen.
• the application thickness was 4 g / 100 cm 2 .
• the application of the engobe immediately followed the application of the glass-like intermediate layer (wet-on-wet application).
• the bricks were fired in an industrial tunnel kiln at 980 ° C for 48 hours.
• the bricks were burned vertically in cassettes in accordance with the normal method of firing, the bricks touching each other in a punctiform and planar manner. After the fire, no injuries to the engobe layer were visible at the contact points.
• a glass cylinder open on both sides with a diameter of 8 cm was placed on the surface and sealed with a silicone ring.
• the cylinders were filled with water up to a height of 10 cm.
• a water stain was visible on the underside of the uncoated bricks after three hours. In the case of the coated bricks, water loss was not detectable within the measurement accuracy.
• Initial limescale deposits were observed after three days on the uncoated bricks at the areas exposed to water. There were no limescale deposits on the coated bricks.

Landscapes

• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Glass Compositions (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Finishing Walls (AREA)
• Aftertreatments Of Artificial And Natural Stones (AREA)
• Paints Or Removers (AREA)
• Ceramic Products (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6263984

Family Applications (1)

Country Status (3)

Families Citing this family (5)

Family Cites Families (6)

• 1985
  • 1985-03-02 DE DE19853507375 patent/DE3507375A1/de active Granted
• 1986
  • 1986-02-19 AT AT86102115T patent/ATE49442T1/de not_active IP Right Cessation
  • 1986-02-19 EP EP86102115A patent/EP0193790B1/de not_active Expired - Lifetime
  • 1986-02-19 DE DE8686102115T patent/DE3668205D1/de not_active Expired - Lifetime

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