Characteristics and properties of cement/concrete
There is probably no person who has not encountered the need to use cement. It is a truly versatile material that is used everywhere. Not only is it convenient and easy to use, but it is also non-toxic, hypoallergenic and boasts a long service life. Even the fillings dentists originally used were cement fillings.
Cement is a powder of clinker stone, which in nature and in industrial production is formed by heating clay and limestone to 1,500 degrees. The clinker granules are then mixed with other additives, such as gypsum, and ground to a powder. When cement interacts with water, it forms stone. It is this quality that attracts builders and other stone lovers.
The mortar obtained on the basis of cement powder and water is called concrete. Therefore, in principle, to buy concrete or cement means the same thing. It is very important when choosing cement to look at the date of manufacture. Because despite all the advantages of this material, one of the main drawbacks is precisely its short lifespan. Usually it is only 2 months from the date of manufacture. Therefore, try to buy cement immediately before the construction work and be sure to study the storage time. What to do if you have purchased good cement, but it got a little bit stale? You can restore its strength by adding plasticizers to the mixture.
Advantages of artificial stone made of concrete and cement
Recently, cement has been actively used for the manufacture of decorative stone and bricks. With this material, it becomes possible to cover almost any surface with significant advantages over natural stone:
- concrete stone weighs much less than natural stone;
- with the help of a mold for casting, you can get all the stones of the same thickness, which greatly facilitates installation;
- there are endless variations in the design of artificial stone, a variety of shapes and patterns;
- its pricing policy is generally affordable and allows you to save a lot;
- tiles made of concrete has a fairly large time resource and can last from 20-25 years.
The variety of tiles that can be obtained, using only concrete mixed with some components, is truly amazing. This and imitation of marble, and granite, and labradorite, as well as almost any stone that is used for tiling. If all the nuances of manufacturing are observed, even an experienced eye will not easily distinguish between natural and decorative stone.
Cement has good sound insulation. Therefore, facing the walls of your home, even a thin layer of concrete tiles, you will protect yourself from excessive street noise and shouting. Cement tiles are not recommended to put indoors, because although it is lighter than natural stone, it is still much heavier than gypsum tiles. In addition, cement is superior to gypsum in price and shelf life. So, if your home is not very humid rooms, it is advisable to do tiling from gypsum. In a previous article, we told how to make decorative (artificial) stone from gypsum for interior decoration.
But for exterior cladding works concrete decorative tiles are suitable as well as possible. Modern craftsmen think through the design to the smallest detail and use in the facing of one object up to several different types of tiles. For example, the socle part of the building lined with imitation boulders, the middle line – slate rock, and the top of the building – artificial brick. Of course, it is not necessary to experiment with many forms at once – the facade, lined with solid decorative bricks of one kind is not inferior in its effectiveness and beauty.
Now it is very fashionable to use concrete tiles in the street decoration of cafes, restaurants, parks, and stores and office space. […]
How to make a decorative (artificial) stone from concrete with your own hands
Artificial (decorative) stone from concrete can also be made by yourself. It does not require special skills and tools. Also, it will not be necessary to call a master for facing the facade, which is usually required when working with natural stone. Artificial stone from cement is usually very easy to install and you can work with it the same way as with gypsum tiles – laying tiles seamlessly or with the expansion of joints. The only thing you may need to do is lay the tiles before laying them on the ground to predict the resulting pattern in advance. This is especially appropriate for fancy patterns with different sized stones.
Concrete decorative stone for facades is made by pouring concrete into a specially prepared mold. Usually sand or other materials are added to the mortar depending on the desired result. For example, to obtain fine-grained inclusions of stone crumbs, claydite or other ingredients are added to the mortar. It is ideal to add sand sifted with a fine fraction – then the mortar will be uniform and more homogeneous.
After kneading the mortar, it is poured into forms, which are spread on the table. At large production facilities, these are vibrating tables, which allow the concrete to mix evenly with vibrations. Many craftsmen make such tables at home on their own or simply make the table vibrate – the vibration time is only 3-5 minutes. If you can not make a vibrating table, try to shake the mold a little during the specified time to ensure better adhesion of the components.
Cement tiles take a long time to dry, so you must have patience and a few molds – as the setting time of one pour is from 12 hours. After taking the stone out of the mold, another additional drying time will be about 2 weeks. Do not rush with the laying of tiles, otherwise instead of a beautiful facade can get solid frustration.
In addition, it is worth remembering that the optimal temperature for working with stone is 5 to 25 degrees Celsius. Therefore, do not hurry to install tiles at lower or higher temperatures, so as not to shorten the life of your stone. Also, keep in mind that painting the product before kneading will make it more resistant to fading and you won’t have to update the top coat of paint additionally after attaching it to the wall.
Step-by-step instructions for making stone out of cement
1. Prepare all the necessary ingredients:
- cement, water and sand in a ratio of 3:1:1;
- iron oxide dye in a ratio of no more than 3% of the weight of the dry ingredients;
- trowel for leveling;
- reinforcing mesh for strength;
- release agent for the mold;
- concrete mixer or drill with a mixer attachment;
- stone mold;
- a bucket or other mixing container.
2. Mix the dry ingredients together. If you add any other compositions to the mixture, they must be thoroughly mixed before mixing. The sand should be fine and thoroughly cleaned or sifted through a sieve.
If you are using a concrete mixer, then pour water into it and turn it on. If not, then fill the desired amount of water in a bowl for mixing. Now we pour the dye into the water and mix it. If you want to get bright light colors of decorative tiles, it is desirable to buy cement white. However, this will come out an order of magnitude more expensive. After dyeing the water, we pour gradually the resulting dry mixture and begin to stir with a drill.
4. Mix the cement long enough so that the mixture becomes homogeneous and has the consistency of a thick, viscous sour cream. It should not drip or pour, but rather overlap. The less water in the composition, the stronger the initial stone is obtained.
5. After the end of mixing we spread the composition in greased with a separating grease. The concrete is poured halfway, and then with special vibrating movements, using a table or by hand, the concrete is shaken in the mold until it is homogeneous. A layer of reinforced mesh can then be placed to increase the strength of the concrete.
6. Pour the form to the top of the remaining composition, flatten it with a trowel. Now it is again necessary to give the future stones a vibration for an even distribution of the mortar. Shake the molds or turn on the vibrating table for about 3-5 minutes.
7. Leave the stone to dry for about 12 hours.
8. We separate a stone from a form and we send for final drying for about two weeks.
9. After drying, you can additionally coat the tiles with a dye.
Facade finishing with artificial stone
Decorative (artificial) stone facade finishing is possible without inviting a specialized master at home. You only need to stock up on manufactured tiles, adhesive material, primers for processing walls and tools for them. Before laying stone, you need to decide whether you plan to work with or without seams.
If you want to lay out artificial facade stone with seams, you need to buy a special grouting mixture or make it yourself, a construction syringe or just a cellophane bag. The distance between the seams should not be more than 12 mm. It is also necessary to prepare a rag, so that the decorative facade stone is not affected by the cement glue during installation – it must be wiped off immediately.
Decorative stone for the facade of the house is laid on a carefully treated surface. So, all the walls are aligned, cracks and crevices are carefully sealed with plaster, after which the plaster must dry within a day. The evenness of the wall is checked with a level – it is necessary to check in all directions: vertical, horizontal and diagonal.
After levelling the wall with plaster work, proceed to the stage of priming the walls. Primer protects the wall from the development of various microorganisms, mold, fungi, and also increases adhesion. It is better to apply two layers of primer, drying them well according to the time specified in the instructions.
After all the preparatory work, you can proceed to the external finishing of the wall with decorative stone. To do this, you need to prepare an adhesive or cement mortar. You can make it yourself or buy a ready-made mixture in a construction store. Mix as much composition as you need for one masonry.
Before laying, it is advisable to lay the tiles on the ground to obtain a ready-made pattern. You may need a circular saw to trim the stone to the desired size. All prepared tiles are cleaned from behind with a metal brush to increase their grip on the wall, as well as to clean off dust.
The tiles are laid from the bottom up with an indentation of 5-10 centimeters from the ground – so you will protect it from the appearance of mold and other adverse processes. Each subsequent layer is leveled, if you are laying stones with a geometric pattern. In case of seamless laying, the stones are laid as close to each other as possible.
Apply the adhesive with a toothed trowel to the back surface of the tiles and the wall itself. After placing the tiles against the wall, you can tap on it with a special rubber mallet for better anchoring. If you get glue on a tile, you should immediately wipe it with a previously prepared rag.
Laying tiles begins with the corners of the room, door and window openings. If you put an even tile, then each previous layer aligned by level. Grouting of joints is performed one day after the facade work. We put the grouting material in a construction gun, syringe or just a bag with a cut corner and spread it evenly between the bricks. After half an hour, smooth the seams with a grouting tool.
After your stone dries, you can coat it with a hydrophobizer – this will protect it from moisture penetration and freshen the color.