- Choosing a manufacturing method
- Equipment: what to buy and what to do yourself
- Production cycle, disassemble in stages
- What is the optimal composition of slag concrete
- Cinder block storage
The profitability of a homemade cinder block is not in doubt, but are there really reliable ways to ensure consistently high quality at sufficiently high production volumes? Let’s try to answer this question and consider the main methods of homemade cinder block with our own hands.
Choosing a manufacturing method
Actually, there are not so many ways of making a cinder block, as there are devices for this. In all cases, slag concrete must be kneaded in a concrete mixer, in no case manually. At this stage, the sequence of adding ingredients, their proportions, duration and other mixing features play a role..
But for forming a cinder block, there are a large number of all kinds of dies, presses and machine tools. In general, all production methods can be divided into:
- manual, when the mass is formed by compaction in single forms;
- partially mechanized, where manual lever presses are used;
- fully automated, based on vibration shrinkage or hydraulic pressing.
Obviously, mechanization improves the accuracy of production parameters; therefore, the methods of lever pressing and vibration shrinkage are most preferable. Small hand tools will be relevant if you only need to produce a couple of hundred stones.
After forming and setting the mass, the cinder block must be removed from the mold. These actions should also be mechanized, most of the marriage appears precisely at the stage of setting. The simplest and most reliable devices for this are the lifting block of forms and the shutter.
Mechanisms can also be used for drying and storage. At least when moving the raw material to the main drying place, it is preferable to use carts and manual fork lifts.
Equipment: what to buy and what to do yourself
The desire to save is quite reasonable, but there is equipment that is very difficult to assemble by yourself and vice versa: you simply cannot buy some accessories.
A good concrete mixer is quite expensive. It must be really powerful and reliable, so pay attention to the gear mechanism and the reliability of electrical commutation. Also remember that the larger the hopper, the easier it is to keep the correct proportions..
Do it yourself with a manual rammer. The shape can be knocked down from boards connected by symmetrical grooves. To emboss the voids, several bars and pads are stuffed onto the cover. The height of the mold should be greater than the cinder block, this is the tolerance for shrinkage and tamping. Such forms can be made in dozens and carry out primary drying directly in them. They are not suitable for long-term use – the tree will simply lead from moisture.
Lever hand presses sometimes make sense to order from the manufacturer, since the market is filled with handicrafts. For a guarantee, order only the equipment that has been seen in operation at least in the video.
If you decide to build a manual press yourself, pay attention to the so-called double hen. The machine is easy enough to make, having basic locksmith and welding skills. The main thing is not to forget to ensure the taper of the pipes that form the voids and the strictly vertical course of the block of forms. Pressing on such a machine can be completely replaced by a vibration motor rigidly attached to the mold.
The vibrating table is definitely worth making yourself. This is facilitated by both the individual conditions of a particular production facility and the high cost of such equipment. All that is needed for manufacturing is a 100-120 mm pipe, four wheel struts springs, a piece of sheet steel 3-4 mm thick and some angle steel. Naturally, the vibration motor will be the most costly part, however, the total cost of the table cannot be compared with the price of existing solutions..
In more detail about how to make a vibrating table yourself, we talked about in the article “How to make a vibrating table for a cinder block with your own hands”.
Production cycle, disassemble in stages
To prepare cinder concrete, you first need to mix bulk materials, then add water in small portions. You need to knead until the mixture acquires sufficient plasticity and stops crumpling if you squeeze it with your hands. It is better to add water with a spray, gradually wetting the mixture to a semi-dry state.
The prepared mixture can be poured directly onto the cement floor or onto a rigid sheet substrate near the machine. From there we collect it with a shovel and carefully fill out the form. Periodically, it is necessary to compact the concrete with vibration shrinkage and squeeze out large air bubbles. When the form is filled to the brim with the mixture, it must be tamped.
In some machines, for this, a reciprocal matrix with a slight oppression is used, with which the cinder block is compacted in vibration mode. In other cases, this same frame is connected to a system of levers and simply squeezes the mass inside the mold. At the end of molding, wait 5-10 seconds and remove the mold from the product, leaving it on the floor for preliminary drying. If the molds are equipped with flaps, it is better to immediately lift the unit and place the product on a pallet..
The cinder block is dried from several hours to several days. It all depends on the composition of the mixture and the technical equipment of the site. Subsequently, the products are carefully transported to the storage area, where they are stored.
What is the optimal composition of slag concrete
It is better to use granite screening as the main filler. Its structure is small flakes, such a material is well bonded in the mass and gives excellent strength. A lighter, but not so hard cinder block is made from crushed slag from energy and metallurgy enterprises. The latter type is characterized by the best thermal insulation properties..
Cement – only Portland grade no lower than 400. More precisely, it is allowed to use grade 300 cement, but with an increase in its content by 15-25%.
Sand is used in the cinder block to increase density, which is not always required. The material must be of a career origin, it must be washed. In total, sand in the total mass is up to 20%. The filler is mixed with cement 400 in a ratio of 8: 1 or 9: 1.
What else can be included in:
- sawdust of all types;
- foam crumb;
- brick, concrete battle;
- plasticizers and modifiers.
The use of the latter will ensure early adhesion of the mixture and relatively free setting of the products. It is also recommended to use additives to increase frost resistance. It will be useful to familiarize yourself with the standards set out in GOST 6133 as amended in 1999 – there are not only requirements for the feedstock, but also the rules for organizing production, some technical conditions and quality control methods.
Cinder block storage
The cinder block reaches full hardness a few weeks after manufacture. All this time, it undergoes natural outdoor drying under a canopy. If there is no space for storing the cinder block in one layer, it is allowed to stack pallets with one row of cinder block on top of each other. For the main drying period, it is important to ensure that the stack is well ventilated and moisture is freely removed..
After two weeks of drying, the cinder block can be stored without pallets, but be sure to at least cover it so that the rainwater does not wash out the bonding substances. If a cinder block is needed for your own construction, prepare it in advance: one winter in street conditions and most of the marriage will manifest itself.