ACTE

ACTE can mean:

Autoclaved aerated concrete

Autoclaved aerated concrete (AAC), also known as autoclaved cellular concrete (ACC), autoclaved lightweight concrete (ALC), autoclaved concrete, cellular concrete, porous concrete, Aircrete, Hebel Block, and Ytong is a lightweight, precast, Foam concrete building material invented in the mid-1920s that simultaneously provides structure, insulation, and fire- and mold-resistance. AAC products include blocks, wall panels, floor and roof panels, cladding (facade) panels and lintels.

History

AAC was perfected in the mid-1920s by the Swedish architect and inventor Dr. Johan Axel Eriksson, working with Professor Henrik Kreüger at the Royal Institute of Technology. It went into production in Sweden in 1929 in a factory in Hällabrottet and quickly became very popular. Siporex was established in Sweden in 1939 and presently licenses and owns plants in 35 locations around the world. In the 1940s, the trademark Ytong was introduced, and was often referred to as "blue concrete" in Sweden due to its blueish tinge. This version of Ytong was produced from alum shale, whose combustible carbon content made it beneficial to use in the production process. The competing concrete brand Siporex produced in Tuzla, Bosnia, used other raw materials. "Ytong" acquired Siporex and today produces "Siporex" under "Ytong" brand in Tuzla, Bosnia factory. Unfortunately, the slate deposits used for Ytong also contain uranium, which makes the material give off radioactive radon gas to the building. In 1972, the Swedish Radiation Safety Authority pointed out the unsuitability of a radon-emitting construction material, and the use of alum slate in the production of Ytong ceased in 1975. Ytong produced after 1975 has used raw materials without the uranium content.