Expanded clay aggregate

Expanded clay is a building material with various applications. Expanded clay is no foam concrete.

Production

The raw material calcium deficiency clay with finely divided organic ingredients used. This is ground, pelletized and fired at around 1200 degrees Celsius in the rotary kiln. This burn the organic additives and the material swells spherical by the carbon dioxide produced by burning on. Expanded clay is reached four to five times the initial volume. The core is closed porous sintered surface.

History

First experiments for the production of expanded clay were made in 1917 in a brick factory in Birmingham / USA. Was invented by S. J. Hayde, so the material is referred to in the U.S. even today as Haydite. The case was taken up in Denmark and further developed. As an abbreviation for "lightweight expanded clay aggregates" ( lighter, expanded clay surcharge ) here Leca has been introduced. It was followed by the Netherlands, Great Britain, Sweden ( Sillit ) and the USSR ( LECA ). In Germany the first expanded clay was taken in 1955 in Hennstedt (Dithmarschen ) in operation.

Use

Because of the almost ideal spherical shape with a diameter up to 40 mm expanded clay is suitable as an additive in mortars, concrete and clay. It is therefore used in the preparation of a dense structure and lightweight aggregate concrete. Grains with a diameter of up to four millimeters are used in masonry, plaster and screed mortar. In this case, the low weight as well as the good insulating properties of expanded clay be exploited in particular. Without further processing or treatment expanded clay can be installed as thermal insulation and space stable bed.

In the Garden and Landscape expanded clay is used for soil improvement, for roofs and in hydroponics. Expanded clay is a innerter substrate replacement of widely used in hydroponics. Since clay pebbles can not bind nutrients, here's the nutritional content can be exclusively through the water ( nutrient solution ) control.

Special Applications

In addition to these standard applications, there are other applications for expanded clay:

  • Ceramic filter for air and gas purification
  • Filter body for water purification and sewage treatment plants
  • Kolonnenbildner in bioreactors
  • Carrier substrate (carrier ) for mycorrhizal fungi
  • Carrier substrate (carrier ) for pollutant- degrading bacteria in the water and soil remediation
  • Soil infiltration
  • Salt-free winter Infill
  • Catalyst support
  • Expanded clay bricks for masonry

Confusion

Expanded clay is not identical to the porous concrete sporadically referred to as swelling concrete.

Hennstedt (Dithmarschen)
130741
de