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Lightweight expanded clay aggregate (LECA) or expanded clay (exclay) is a lightweight aggregate made by heating clay to around 1,200 °C (2,190 °F) in a rotary kiln. The heating process causes gases trapped in the clay to expand, forming thousands of small bubbles and giving the material a porous structure.
Semi-Hydroponics (Semi-Hydro or S/H) was the first passive hydroponic technique utilized for orchids, originating in the early 1990s, using Lightweight Expanded Clay Aggregate (LECA) as a medium in solid-bottomed containers, into which one or two, small-diameter holes were placed in the sidewall, setting the depth of the internal reservoir.
In a study comparing lightweight expanded clay aggregate (LECA) and expanded vermiculite (EV), two materials used to make concrete, to a mycelium grown brick, the mycelium grown brick was found to be a better insulator. [13] These results are similar when comparing a different mycelium based composite with extruded polystyrene.
This was the case, for example, with the patent for the manufacture of lightweight concrete slabs, which Lemvigh-Müller & Munck A/S acquired in the mid-1930s. In 1939, A/S Dansk Betonklinker was founded, and the first rotary kiln in Sydhavnen began firing the product that was to become success under the name LECA (Light Expanded Clay Aggregates).
Expanded clay aggregate. Baked clay pellets are suitable for hydroponic systems in which all nutrients are carefully controlled in water solution. The clay pellets are inert, pH-neutral, and do not contain any nutrient value. The clay is formed into round pellets and fired in rotary kilns at 1,200 °C (2,190 °F). This causes the clay to expand ...
The use of the expanded clay aggregate is economically recommended, particularly in the concrete production, since it reduces the bulk density while minimizing the total weight of the constructions. It can be concluded that the use of expanded clay is very important in civil constructions, due to its overall weight, cost and maintenance.
After the LECA, some 2 billion years ago, the eukaryotes diversified into a crown group, which gave rise to animals, plants, fungi, and protists. Eukaryogenesis , the process which created the eukaryotic cell and lineage, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms.
Soil sieve nests with dry soil aggregates after removal from a laboratory drying oven. Soil aggregate stability is a measure of the ability of soil aggregates—soil particles that bind together—to resist breaking apart when exposed to external forces such as water erosion and wind erosion, shrinking and swelling processes, and tillage.