Concrete and concrete products (ICS 91.100.30)

Ministerial Decree No. 223 /2021 (2 pages, in Arabic) mandating the Egyptian Standard ES 1401 "autoclaved aerated concrete blocks - requirements" (20 page(s), in Arabic)

The Ministerial Decree No. 223 /2021gives the producers and importers a six-month transitional period to abide by the Egyptian standard ES 1401.

This standard specifies the requirements for autoclave porous concrete blocks, which is a cement product based on hydrated calcium silicate, where a low density is obtained by including an agent that produces microscopic voids that is treated using steam under high pressure.

The raw materials used in the production of porous concrete blocks by autoclaving portland cement or mixed cement, quartz sand, water, lime, gypsum or anhydrite, and void-generating materials. the quartz sand used can be replaced with any fine siliceous aggregate which is usually ground to a fine powder before use. Fly ash can also be used as an alternative to sand. The raw materials are mixed together to form a slurry and poured into steel moulds. as a result of the chemical reaction occurring in the slurry the increasing in volume occurs. The product is mechanically cut into blocks of different sizes after setting and before solidification. Then the blocks are treated with steam under pressure in an autoclave, where the material turns into hardened calcium silicate.

Worth mentioning is that this standard is technically identical with modification with  ASTM C1693- 11(2017).