All you want to know about concrete blocks in Pakistan
Concrete blocks were first used in United stated for the substitute of wood and stone for building of home. The new form of material use to made building became famous in 1920s. Hundreds of houses were built by using concrete blocks. A concrete block is building material that is used in construction of all walls. It is precast concrete product that is used in construction of building home and commercial buildings the word precast is used to show that the blocks are already hardened and formed before bringing them to the construction site. Usually the concrete blocks are hallow from inside but have smooth or design on the sides. The concrete blocks are held together by using fresh concrete to form it in desire length and height.
Material used for making of concrete blocks
The concrete blocks are usually made with mixture of cement gravel water and sand. This material produces light grey color block that has fine surface texture and has high strength. Usually the concrete blocks weights around 17-19 kg. usually the concrete mixture that is used in concrete block contain high percentage of sand and contains low percentage of concrete gravel and water than the concrete that is used generally for construction of home and buildings. When the block mold is removed it holds its shape and it is dry and stiff. Concrete blocks that are light in weight replace sand and gravel with expanded clay slate or shale. The expanded clay shale or slate is produce by heating the raw materials up to 2000F. The concrete block also contains various chemical mixtures known as mixtures to increase the strength, workability and alter curing time. Certain pigment may be added in block to give it a uniform color block look the surface of block may be coated with glaze in some cases to give it a decorative look.
Design of concrete blocks
Usually the size and shape of concrete blocks are standardized to show uniformity in construction of buildings. Some block manufactures also offer variation if you want to achieve any unique effects to your structure of your buildings. Manufacture also offer blocks that are specifically designed to resist the water leakage. These block that are resistant to water leakage include admixture to reduce the concrete absorption property
Process of concrete blocks
Proportioning- the quantity of the material used in making of concrete are set by standard codes and also on robustness needed.
Mixing the mixing of batches should be exactly same and mixing should be done in mixture to create a homogenous mix. The mixing should be done until uniform material is formed
Compacting-the block should be compact and should be in proper size without any broken edges.
Curing- the blocks should be cure in water tanks and should be kept in moisture for 14 days. It is recommended that water of tanks should be changed after every 4 days
Drying- once the blocks are cure they are dried for 2 to 3 weeks after that the concrete blocks are ready to use if you don’t follow the instruction you may feel crack in the walls
Types of blocks
Solid concrete blocks- they have the highest strength that is 5-8 mpa. These blocks can be manufactured at site to reduce transportation cost and taxes. The lowest water absorption among its class. They are used in low rise construction.The typical size availability of these block are 400x200x100mm, 400x200x200mm and 400x200x150mm
Hallow concrete blocks- they are light in weight has compressive strength of 5-8 mpa, these blocks can also be manufactured at site to reduce transportation cost and taxes, the wastage is high in these types of blocks. They are used in low rise construction the typical size availability of these block are 400x200x100mm, 400x200x200mm and 400x200x150mm
Lightweight aerated concrete block- they are very light in weight to handle the dead load on structure. It is to carve for service like plumbing and electrical. You need less time in installation and are also less labor intensive. They are used in high rise construction. The unit cost of these concrete blocks is high. the typical size availability of these block are 600x200x100mm, 600x200x200mm and 600x200x150mm
Cellular Lightweight Concrete Block they are very light in weight to handle the dead load on structure. It is easy to carve for service like plumbing and electrical. You need less time in installation and it is also less labor intensive. It compressive strength is 3- 4 mpa that is very low among its substitutes. They are used in high rise construction. The unit cost of these concrete block is high the typical size availability of these block are600x200x100mm, 600x200x200mm and 600x200x150mm
Fly Ash Blocks- It is easy to carve for service like plumbing and electrical. It compressive strength is 3.5- 5 mpa. These blocks can also be manufactured at site to reduce transportation cost and taxes. You need less time in installation and It is also less labor intensive. They are best for mid and low level construction the typical size availability of these block are 400x200x100mm, 400x200x200mm, 400x200x150mm 600x200x100mm, 600x200x200mm and 600x200x150mm
Quality test for concrete blocks
The test recommended for bricks apply on concrete blocks. The falling test should be performed
- See the dimension.
- Edges should be straight sharp and right angles.
- They should be free from cracks.
- It should not break down if thrown from the height of 1.0 m.
- The percentage of broken blogs on truck loading should not be more than 5 percent.
- See the average weights and density of blocks should not be less than 100 kg/m3.
- The water adsorption should not be more than 10 percent weight of block.
Conclusion
A concrete block is building material that is used in construction of all walls. The concrete blocks are usually made with mixture of cement, gravel water and sand. This material produces light grey color block that has fine surface texture and has high strength. Usually the size and shape of concrete blocks are standardized to show uniformity in construction of buildings. In this article we have discussed about types of concrete block, design process and quality test for concrete blocks. If you are searching for the best concrete blocks in Pakistan then you have come to right place. We have updated the best concrete blocks for you. Just send message to multiple suppliers and get different quotes.