The term definitely sounds interesting, but more than the ‘’interesting’’ part, your question is regarding what these kind of processes really are. It is actually a secondary process of how paver blocks are manufactured. Here’s what you should know of the secondary process in the paver blocks manufacturing process.
What is the need for secondary processing?
The secondary processing element is done to add value to a standard paving unit by creating a special kind of texture. Certain secondary processes like flame-texturing of stone can be done right after the following primary paver production process. However, in the case of concrete and clay products, most of the secondary processing techniques have to be delayed until the paving units have been hardened or cured to well enough to withstand the stresses and rigors formed during the texturing processes.
In these cases, a product has to be stockpiled before it is ready for the nest stage of texturing. This also adds to the cost for the paver block manufacturer. This is one reason why these products may cost a little higher and look more beautiful when compared to any other paver block design. These units would also need to be stored for a period prior to the processing.
Some of the most common secondary processing techniques are –
- Bush Hammering
- Shot Blasting
Most of these processes are termed as destructive processes and so only the high-strength units can be suitable for secondary processing. Likewise, most of these blocks which would undergo future processing are mostly press manufactured, rather than wet cast. It s because this manufacturing method produces tougher and more resilient units that are capable of withstanding the pressure of secondary processing
We’ll give you a better idea of how these processes can benefit a regular concrete paver block.
The process is also called Rumbling and involves purposely damaging the cured units to give them a withered or aged like appearance. The most common method involves dumping the units in the equivalent of an empty concrete mixer and then mix them in a circular motion in a way that they smash against each other as well as the sides of the revolving drum, thereby knocking off the arrises and the corners in the process.
Any modern tumbling paver block machine in India has a unique feature that allows only for a certain degree of damage to be done to the corners and arrises, all of which are specifically controlled. Simultaneously the dust is also removed which was previously generated in the process. Moreover, the units are also maintained in a single layer which enables fully automated handling without human interventions
This process is used to create a lightly roughened texture to one or more surfaces on the paving units. With blocks & flags, it is generally the top surface that fets treated as the sides & base aren’t visible when laid. However, in the case of curbs, the top & the roadside face would be treated, with some units also getting treated on 3 sides or more.
The process involves spraying the units with a shot, which includes small beads of steel fired at high velocity through a compressed air technique. The shot spalls the surface a bit each time, dislodging the tiny particles of concrete with the debris falling to the floor along with the shot. The debris & shot are take out & isolated with the debris sent for disposal while the shot is recycled to be used again & again in texturing further units.
The shot blasting process produces an even degree of texture that can be finely controlled by adjusting the time spent in the blast chamber. The textured product is also cleaner as the shot dislodges away dust when it strikes the paver surface.
Here the block’s surface is hammered by a series of pyramid-like chisels mounted on the hammer’s surface. The hammers continuously strike the unit, picking away at the surface to create a roughened, natural-looking surface.
The primary difference between bush hammering & shot blasting is that that bush hammering is only applied to one surface, whereas shot can be blasted at 2 or more surfaces simultaneously. Also, the texturing produced by the hammer can be repetitive unlike the shot blasted texture which is just random. The aiming feature of the bush hammer at a certain point can be used to create patterned textures, with parts of the [aver treated while other parts are left in their original condition. This effect is more visible on avers where an untreated border is left surrounding a textured panel.
Also, the hammered surface that emerges from the process is relatively clean, as any loose debris just gets blown off the treated surface by the hammering process. In certain situations, the high speed compressed air further helps to clear off any dust.
The technique is Also known as Grinding. The top surface of a unit is ground down (honed/polished) using an abrasive paste containing carborundum powder. For concrete pavers, this has the effect of removing the fine matrix normally found on the surfaces of press-manufactures units & exposing the coarse aggregate within the concrete.
Unlike the previous methods, concrete paving units with polished or ground surfaces tend to remain relatively clean. This also makes them more easy to maintain.
A highly specialised treatment that is extremely popular in continental Europe. This process is a quite different fort the other methods as the treatment takes place immediately after manufacture without any waiting period while the paver is cured. The final result is a uniquely textured product where the exposed coarse aggregate is displayed for best effect while maximum utilization of its natural colour.
The aggregates and matrix for washed pavers are specifically selected for best performance. And right after the paver emerges from the press, the units are elevated at an angle & washed with high-speed water which wipes ff much of the surface matrix along with a small quantity of aggregate and leaves an exposed layer of the decorative aggregate.
The benefit of this texturing method is that the paver’s colour can be wholly delivered by the inherent colour of the exposed aggregate without needing expensive cement dyes, where even the best ones can be prone to fading in UV light.
Different colours of aggregate can be blended to create original hues & the random alignment of individual grains of aggregate within the surface gives a glinting-like feature to the finished product.
If you’re looking to get any of these kinds of pavers you can look into some of the paver products offered by JR rubbers. JR Rubbers offers all the right concrete paver moulds for any kind of pavers. They offer all the complete solutions for the exterior flooring industry with the manufacture and supply of rubber moulds for paver blocks.
They offer a wide range of products like Rubber moulds for Pavers/Tiles/Kerbs/Cover, Blocks, polypropylene Plastic Moulds Pavers and other customized products. They also provide paver production lines like Mini paver plant, semi-mechanized paver plant and fully automatic paver plants.