DE20111132U1 - Ready mix of a light clay - Google Patents

Description

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HEMP FIBER

UCKERMARK

Light clay mixture

made of hemp, dried clay powder and sand

Current status of raw materials

Hemp and flax have long been considered raw materials that were also used in the construction industry.

Clay was one of the most important building materials, and not just for the poor. Its use was developed in particular for clay building in places where there was not enough lumber available. In Europe, it was particularly used in the infill of half-timbered structures and in solid clay walls.

Organic material, usually cereal straw, and sand are usually mixed into the clay.

New buildings made of clay were increasingly pushed out in the 20th century. It is only in the last 10 years that clay walls or clay structures on solid walls have become increasingly popular again. Occasionally, a mixture of clay and sand (gravel) is used instead of clay. This mixture of clay and sand is brought to a consistency that is very similar to clay. The behavior in the building structure is comparable.

Current status of lightweight clay walls and thick clay plasters

The development of the construction industry, supported by legal requirements (Construction Heat Ordinance) towards buildings with optimized heat management, in particular an energy-saving construction method for buildings to be constructed or modernized with the aim of keeping the expenditure for generating thermal energy for air conditioning the buildings to a minimum through suitable thermal insulation, changed the market for building materials.

The market leader in the field of thermal insulation of new and old buildings is the use of insulation boards made of mineral wool or expanded polystyrene. In recent years, alternatives have been added, including alternatives that have certain ecological advantages.

In addition to the advantage of thermal insulation, there has also been a demand for sufficient heat storage capacity in buildings in recent years. In particular, lightweight walls with lightweight thermal insulation elements often prove to be structures with very low heat storage capacity.

HEMP FIBER

UCKERMARK

Lightweight clay walls offer an excellent alternative here. In addition to thermal insulation and heat storage capacity, lightweight clay walls also provide the very pleasant indoor climate typical of clay walls.

This room climate is largely dominated by the moisture-regulating properties of the clay.

There are various methods of processing clay in wall areas, both for load-bearing walls, wall structures in front of load-bearing walls, and thermal plasters from 3 cm on existing walls.

1. Clay is mixed with straw chips and sand with the addition of water. Since the consistency of the clay varies greatly and drying cracks are to be avoided, various additives are added, such as cow dung. This clay mixture is compacted very firmly in a formwork by "tamping" it hard. With good tamping, a load-bearing rammed earth wall is created.

2. Clay wraps were made from long straw that was wrapped around a stick with clay slurry and stretched into a compartment after pre-drying. They were used for floor constructions or for filling in half-timbered houses.

3. Walls or half-timbered infills were often made of clay bricks using a clay slurry. The clay bricks were made in a similar way to the rammed earth walls and dried in the air.

4. As an alternative to clay bricks, unfired clay bricks (green bricks) were also bricked up with clay slurry to form a "clay wall".

5. The classic method of stacked earth walls has been supplemented by the addition of other organic substances such as wood chips. There are already ready-made clay-wood chip mixtures on the market.

6. For clay plasters, some processors use a clay-sand mixture as a quasi-clay plaster instead of pure clay.

However, there are some disadvantages:

Clay is always different. It must be mixed individually (sand and organic substances) to avoid cracking when it dries out; it cannot be standardized.

A mixture of clay and organic substances can only be stored for a very limited time due to the moisture in the clay. A dried mixture of clay and organic substances in granular form is not known as a building material, except as clay brick.

In addition, clay and loam in their raw form (undried and not granulated) are very difficult to mix with other substances.

HEMP FIBER

UCKERMARK

Task of the utility model

There are obviously a large number of variants for building a clay wall or a lightweight clay wall. The new utility value of the utility model lies in its simple and quick processing with excellent building physics properties. A standardized product with an almost unlimited storage life is made available to the construction site and made processable through very simple preparation on the construction site.

Ready-mix for a lightweight clay wall

According to the invention, the utility model relates to a dry mixture of flax or hemp shives, dried, fine-grained clay powder and sand or gravel. Alternatively, the dry mixture consists of flax or hemp shives and dried, fine-grained clay powder, to which dry sand or gravel is first added on the construction site to form the finished mixture.

This dry mixture (ready-made mixture) is mixed with water to form a processable medium. A concrete mixer, a forced mixer or something similar can be used for this. Alternatively, the water can be mixed in a mason jar or similar container.

Alternatively, the utility model consists of an earth-moist ready-made mixture of flax or hemp shives, dried, fine-grained clay powder and sand or gravel and water, which is ready for processing.

The earth-moist lightweight clay mixture made from the dry mix and water is poured into a formwork and then compacted. Depending on requirements, compaction is carried out by pressing with the foot, using simple tools such as a log or using a pneumatic or electric hammer. Alternatively, the finished earth-moist mixture made from the ready mix and water, equivalent to cement plaster, is applied to a plaster base on a horizontal wall, left to dry for a day and can then be rubbed off, equivalent to cement plaster.

Application examples

Mixing with water should be done with very little water, as clay and sand do not set, but need to dry out. The slightly moist mixture should be so dry that it has a distinctly grey, moist appearance, but its consistency is much drier than an earth-moist concrete mixture. For 25 kg of ready-mix, approx. 2 litres of water.

Insulating plaster:

HEMP FIBER

UCKERMARK

The lightweight clay mixture made from the dry mixture and water can be plastered onto brickwork, a concrete surface or a clay wall. The surface must be moistened beforehand with a brush. The insulating plaster is only suitable for plaster thicknesses of 3 cm or more. After it has dried, it can be rubbed off with a clay slurry.

Clay wall:

A water-repellent formwork is mounted in front of an existing solid wall.

The lightweight clay mixture made from the dry mix and water is poured into a formwork 10 - 20 cm deep and tamped under low pressure. The formwork should be built parallel to the filling to allow good access to the cavity.

A free-standing partition wall can also be constructed in a similar way, but with paneling on both sides.

The rooms must then be allowed to dry out, taking the season into account.

Claims (3)

1. Light clay mixture for earth-moist processing in a building, characterized in that the dry mixture consists of the stem pulp of the hemp or flax plants (shives) and dried clay granules with a grain size of less than 1 mm or clay powder and this dry mixture can be mixed again with the addition of water or sand and water in order to be processed in the building. 2. Light clay - mixture for earth-moist processing in a building, characterized in that the dry mixture consists of the stem pulp of the hemp or flax plants (shivs) and dried clay granules with a grain size of less than 1 mm or clay powder and sand or gravel and this dry mixture can be mixed again with the addition of water or sand and water in order to be processed in the building. 3. Light clay mixture according to claim 1 or 2, characterized in that the light clay mixture contains additional substances, in particular lime, chalk, dyes or color pigments, water glass or other substances.