Biltech Built ‘O’ Fast Block Joining Mortar is a Thin Bed AAC Block Jointing Adhesive. It is high strength, Pre-Mixed, Quality assured Mortar as per ASTM-C-1660 -P10. It is specially formulated which does not required post curing and easily applied, giving a better bonding with higher air entraining properties. “Built ‘O’ Fast Block Jointing Mortar is a masonry mortar for use in laying various types of Flyash/Concrete bricks or blocks and AAC Blocks. It replaces conventional jointing mortar of 12-18mm thickness with highly versatile 3-4mm thickness mortar.