A concrete block is essential for construction of concrete structures. For example, it is a basic necessity for construction of a concrete wall or any other concrete structure. A concrete block making machine also known as a concrete masonry unit makes process of manufacturing cement bricks simpler.
Process of making concrete blocks has evolved over the years from a completely manual process to a fully automated process. There is improvement in production as well from 10 blocks an hour doing it manually to over 2000 blocks an hour using automatic concrete block making machines.
What is a block making machine?Design of a block may vary depending on the type of construction and country. However, a block making machine is essential to make concrete blocks of any kind. These machines can be either manual or automatic. These blocks can be simple ones, waterproof ones or even those with custom requirements.
Process of making concrete blocks
These manufacturing units can either be solely for the purpose of making concrete blocks or some can be multipurpose ones that can also manufacture other concrete products. Plants of this kind have an ability to manufacture high volume of bricks per hour (up to 2000 per hour).
Mains steps of the process:- Mixing:
This process starts by first gathering all raw material like sand and gravel. Next step is to place materials in their respective bins to place on a conveyor belt. A conveyor belt helps transfer this raw material to the weighing section to measure exact amount of all material.
Once the process of weighing them is complete the process of mixing begins, where all the ingredients are blended for a short period of time. There are several types of mixers for this task. Planetary mixer and pan mixer are two popular ones that are efficient and serve the purpose.
The blending process is short after which water is added to the mixer. It is necessary to regulate temperature of the water prior to adding it to a mixer. This is a good time to add the necessary chemical and coloring pigments as well.
- Molding:
At the end of a mixing cycle all concrete is dumped on an inclined bucket conveyor to transport to an elevated hopper. Second cycle of mixing starts simultaneously. Next comes the transferring of concrete to another hopper at a steady flow rate. This in turn flows into molds that has several mold liners. Here is where shape of the bricks is defined.
Once the mold is full the weight of the upper mold head coming down compacts the mold. This can also include air or hydraulic pressure and mechanical vibrations.
- Curing:
Pallet of blocks get stacked on a rack with help of an automated stacker or loader after the molding process. This in turns transfers to a set of rails into a curing klin. A curing klin is an enclosed space that can store several racks and moderate steam and temperature as per the requirement.
Once racks are placed in a curing klin, steam is introduced at a low rate like 16 degrees Celsius. Steam temperature varies for different types of blocks. Standard blocks are cured at a temperature up to 74 degrees (Celsius) while the lighter ones up to 85 degrees (Celsius).
Blocks are allowed to remain in here for 12 to 18 hours, however, the entire process can take up to 24 hours.
- Cubing:
Racks roll out of a klin where unstacking of all pallets take place and then pass onto a chain conveyor belt. These blocks then pass through a cuber for the purpose of alignment and then transported out using forklifts for the purpose of storage.