Concrete blocks with core void area more than 25% of the gross area are called hollow concrete blocks.
These blocks are manufactured in various shapes and sizes as shown in the following figure.
Some standard sizes of hollow concrete blocks are as follows.
- Standard Size Hollow Concrete Block – 39cm * 19cm * 30cm
- Hollow Building Tiles – 39cm * 19cm * 20cm
- Hollow concrete block for partition – 39cm * 19cm * 10cm
The face thickness of these blocks is normally kept at 5 cm or more.
Advantages of Hollow Concrete Block Masonry
- fast execution of tasks
Hollow concrete blocks are of uniform and regular shape and have a low weight. This speeds up the execution of the work.
- increase in floor area
It is possible to build thin walls using hollow blocks. Hence it helps to save space and increase the floor area.
- reduces construction costs
Hollow blocks help in saving the construction material and hence the use of hollow blocks reduces the construction cost.
The use of larger size concrete blocks reduces the number of joints in the work and hence helps in saving mortar.
- better insulation properties
Hollow concrete blocks have good insulating properties against sound, heat and moisture.
- more durable
Hollow concrete block masonry can safely withstand atmospheric action and requires no protective covering.
- employment of unskilled workers
Unskilled workers may also be employed in the construction of hollow concrete block masonry.
- Good bonding of mortar and plaster
The presence of a rough surface on concrete blocks provides good bonding of mortar and plaster.