lightweight hollow blocks are a type of concrete masonry unit that weighs less than normal-weight or medium-weight blocks. They are also stronger than regular concrete and can be used for a variety of applications, including load-bearing walls, partitions, and retaining walls.

They are lightweight because they have a higher proportion of expanded aggregate than traditional concrete, which increases their density and reduces their weight. They also have better insulating properties than other types of concrete, and they can be fire-rated for extra protection.

The blocks are formed using a mixture of sawdust, sand, and cement. The ratio of the sawdust to sand may vary between 30% and 70%, preferably 60%. The mixture is hydrated by adding water to the sand and cement.

This mixture is then poured into molds to form the blocks. The blocks are then vibrated and compacted to form a uniform shape.

They can be made of a wide range of materials, including sand, crushed stone, or lightweight aggregate. Some manufacturers of cellular lightweight blocks also use polystyrene, a waste product from thermal power plants, for their mix.

Their lightweight nature can allow them to be shaped easily into different shapes, and they are available in various sizes. Their acoustic and thermal insulation properties make them a popular choice for sound and temperature control in homes and commercial buildings.

They can reduce labor costs by reducing the amount of time it takes to build a wall, and they can be more easily installed than traditional concrete blocks. They can also help workers avoid low back disorders by minimizing the amount of heavy lifting and carrying they have to do on construction jobs.