ALAS AAC BLOCK is an unusual building material with properties that should make it a hit in residential construction — it’s a much better thermal insulator than ordinary concrete, while lightweight, easy to work with and resistant to fire, insects and mould. The only problem is that Indian builders can’t seem to warm up to it. Some residential builders who specialize in energy-efficient designs have tried using AAC, but most have since left the fold.
ALAS AAC BLOCK has a lot in common with ordinary concrete, with a few notable exceptions. Instead of fine and coarse aggregate, ALAS AAC BLOCK uses sand or fly ash plus aluminium powder to create millions of tiny bubbles in the mix. The mixture is placed in moulds and cured in an autoclave, which uses steam and pressure to complete the chemical transformation.
ALAS AAC BLOCK, like conventional concrete masonry units, is laid up with mortar. AAC Blocks are placed over lengths of steel rebar that are cast into the foundation walls, and these holes are later filled with grout. AAC Blocks can be cut with the same tools used for wood — bandsaws are commonly used to cut blocks to size.