Brick is a very popular building material that can be used for the construction of buildings and structures for almost any purpose. Residential buildings, production workshops, pavilions, fences, etc., built from such ceramic stone, are distinguished by durability and excellent performance. Bricks are fastened in masonry during the construction of enclosing structures, foundations, etc. with mortars of a special variety.
Such mixtures are made, of course, with strict observance of certain rules. In case of violation of the established technologies, their kneading will not work as a strong structure and will not last long in the future. Simply put, the brand of mortar for brickwork must be chosen correctly.
Application Features
Technology for the construction of brick structures is used approximately as follows:
- Masonry mortar is spread on the previous row, usually with a layer of 1 cm. At the same time, the length of the row is 4 bricks.
- The solution is leveled and removed with the edge of the trowel starting from the front side.
- The removed mortar is applied to the brick, which is then pressed against the previous one and tapped with a mallet.
The thickness of vertical seams in such masonry is usually 0.8 cm.
Sometimes a slightly different technique can be used for masonry. In this case, the solution is spread over a row with a thicker layer. In this case, the laid brick moves towards the previous one with the capture of the mixture. The latter, when applying this technique (“press”), forms a vertical seam.
Which masonry mortar is best: requirements
After setting, mixtures used in the construction of buildings and structures should not:
- shrink;
- crack;
- s alt out;
- collapse under the influence of temperature changes, mold;
- cause corrosion of metal fittings.
The following requirements are imposed on the masonry mortars themselves:
- high adhesion to brick;
- quick set of strength;
- plasticity.
High adhesion of the mortar to the brick makes the masonry as strong as possible and facilitates the work of the master. Long drying and hardening of the mixture significantlyslow down construction work. Brick, as you know, is a heavy material. And several rows of masonry, which did not have time to harden, the liquid mortar will simply crush.
Slows down the construction of a brick structure and the use of rigid inelastic mortar. It will be difficult for a master to lay a stone on such a mixture. In addition, the use of an inelastic mortar will ultimately adversely affect the quality of the brick structure itself.
Varieties of mixtures
There are two main types of building compositions used for the construction of buildings and structures from brick:
- universal;
- special.
The first type of mortar for brickwork joints is the most popular among builders and is used very widely. For example, it is these mixtures that are used in the construction of walls of residential low- and high-rise buildings, partitions, fences, foundations.
Special mortars are prepared using special additives or high grades of cement, giving them the properties necessary in this particular situation:
- fire resistance;
- moisture resistance;
-
resistance to aggressive environments.
Mixes of this variety can be used, for example, for the construction of walls in production halls, chimneys, foundations.
Main Components
Brand cement mortars for masonry may be different. But in any case, such mixtures necessarily consist of twomain components:
- filler;
- binder.
In the production of a universal masonry mortar, and often a special one, sand is used as a filler. The binder in such mixtures is almost always cement. Masonry mortars are closed in most cases with plain water.
Main component requirements
Sand in the manufacture of masonry mixtures is usually used large river. Quarry material of this type can also be used, but only when building walls for low-rise private country houses.
The brand of mortar for brickwork, among other things, depends on the brand of cement used for its manufacture, as well as its percentage. Such material differs primarily in the degree of strength after hardening.
Cement of low grades is used for the construction of unloaded structures not exposed to negative environmental factors. More durable material is used for the preparation of solutions intended for the construction of walls and foundations. The most common brand of such cement is, for example, M400. There are also varieties of such material, designed specifically for the construction of structures that are exposed to moisture or aggressive agents during operation.
Cement belongs to the group of hydraulic binders. But sometimes, when building any structures, they can also be usedair materials of this variety. These include, for example, clay, lime and gypsum. Such binders are used to prepare special masonry mortars.
Clay, for example, in most cases is used for mixing compositions intended for the construction of structures that are exposed to high temperatures during operation. These can be, for example, chimneys, stoves, fireplaces. Masonry mortars for bricks are rarely made on lime and gypsum. Such mixtures are considered much warmer than cement. However, they also differ in less strength. Such compositions can be used for laying only unloaded insignificant structures inside buildings.
What additives can be used
Universal mortars are usually made using only sand and cement. For example, it is these mixtures that are supposed to be used in the construction of load-bearing walls and foundations. When laying less critical structures, cement mortar can also be mixed with the addition of lime as a plasticizer. Such a mixture is practically not inferior to the usual strength. At the same time, it is more elastic, which facilitates the work of the master. The main disadvantage of mixtures with the addition of lime is considered to be a lower degree of resistance to moisture.
In some cases, special polymeric substances can also be used to increase the elasticity of the solution. But such additives are usually included, of course, only in the composition of factory dry masonry mixtures. When preparing solutions with your own hands directly on the spotin construction, lime is used as a plasticizer in most cases.
The same clay is usually used as a refractory additive in the manufacture of special masonry mortars. Sometimes such mixtures are made using fireclay crumbs. Also, when preparing masonry mortars, additives can be used:
- anti-frost;
- accelerating setting;
- increasing moisture resistance and adhesion, etc.
Marks of mortars for brickwork according to GOST
Properties of mixtures used in the construction of buildings and structures, as already mentioned, depends primarily on the brand of cement and the proportion of mixing components. You can determine the degree of strength of the solution and its purpose, first of all, of course, by its brand. The table below shows the dependence of the latter on the consumption of cement in kilograms per 1 m3 sand/mortar according to GOST.
| Grade of cement/mortar | 150 | 100 | 75 | 50 | 25 | 10 |
| 400 | 350/400 | 255/300 | 100/240 | 140/175 | - | - |
| 300 | 470/510 | 340/385 | 270/310 | 185/225 | 105/135 | - |
| 200 | - | - | 405/445 | 280/325 | 155/190 | 25/95 |
Determines the grade of cement mortar for brickwork, primarily its compressive strength.
Mixes according to this indicator are chosen according to a fairly simple scheme. To determine the brand of such material, you just need to divide the brand of brick into two. In this way, you can choose a solution for the construction of any structures - heavily or lightly loaded. That is, the answer to the question of which brand of mortar for brickwork is best suited when using, for example, M150 stone is M50 or M75, depending on the significance of the structure being built.
It is imperative to follow this rule when buying and making masonry mortar. Cement mixture and brick have different degrees of water absorption and strength. Therefore, there is some contradiction - the stronger the solution, the weaker the masonry. The brick may simply not withstand the shrinkage stresses of a strong mixture, which will lead to deformations and breaks.
Thus, a mixture for ceramic material is selected, depending on the degree of loading of the structure. For example, people who decide to build a house on their suburban area are interested, among other things, in what brand of mortar for brickwork of external walls is most suitable. For the construction of structures of this type can be usedceramic stone from M75 to M200. Accordingly, the mixture is used grades 50-100.
Mobility
The quality of masonry depends on how evenly the seams in it will be filled. To prevent air voids between the bricks, the mortar must differ in a certain degree of mobility. This indicator in the mixture depends on the percentage of the components, as well as their characteristics.
There are only 4 brands of mortars for brickwork according to this indicator - from Pk1 to Pk4. It is believed that:
- Pk1 mix is great for vibrated rubble;
- Pk2 - for non-vibrated;
- Pk3 - for hollow brick and ceramic stone;
- Pk4 - for filling voids in masonry.
What rules should be followed when cooking
Which brand of mortar for brickwork is suitable in this or that case, thus, it is clear. The characteristics of such mixtures are determined depending on the properties of the ceramic material itself. But, of course, the solution will have the necessary qualities only if it is prepared correctly. Only in this case, the finished solution will turn out to be of high quality, and the masonry itself will be durable.
When preparing a mixture both from ready-made dry compositions and from individual components, it is important to achieve its complete uniformity. More recently, such solutions were kneaded in troughs or on sheets of iron,using shovels and hoes. But today, in most cases, even the owners of small country houses have special equipment designed for the manufacture, including masonry mixtures. In our time, the owners of suburban areas make solutions in concrete mixers. When using this equipment, the finished mixture, due to its uniformity, is of the highest quality.
First, the dry components of the mortar are supposed to be laid in the concrete mixer hopper. After mixing them for several minutes, such equipment is turned off. Then 75% of the prescribed amount of water is poured into it. In the next step, the solution is stirred for another 5 minutes. The remaining water is added to it after it has been moved from the concrete mixer hopper to the masonry tank.
Cement before preparing the solution of any special preparation, of course, does not require. The only thing is that before using this material for kneading, you must definitely look at the date of its release. Do not use stale cement for masonry. For example, already six months after the release date, the strength of this material decreases several times. Accordingly, the brand of cement-sand mortar for brickwork prepared from it is also decreasing.
Keep this material, of course, in a dry place. In the USSR, very high-quality cement was produced by firing, the lumps of which, if wet, could be broken up and safely used for laying or pouring concrete structures. Modern material of this typemanufactured using special chemicals. According to many craftsmen, it is inferior in quality to the Soviet one. Therefore, unfortunately, it is impossible to use modern Portland cement that has set in lumps.
Sand before kneading mortar for bonding brickwork must be sieved. Ultimately, no organic impurities or debris should remain in it.
Number of ingredients
The brand of factory-prepared masonry mortar is usually simply indicated on the packaging. When mixing similar compositions directly at the construction site, the components are combined in certain proportions by volume.
When preparing mortar for masonry, cement/sand proportions are commonly used: 1/2, 1/3, 1/4 or 1/5. A plastic solution is made in most cases in the same way. The most popular mixture of this variety among masons is prepared in the proportion of cement / sand / lime, like 1/5/1.
All components are placed in the concrete mixer in such quantities that the output of the solution is not too large. The cement masonry mixture hardens in about 2-2.5 hours. That is, in 1-1.5 hours, the portion prepared in the concrete mixer must be worked out.
Preparation of refractory compounds
How to choose a brand of mortar for cement masonry and in what volumes it can be mixed, we found out above. But what is the right way to make refractory compositions of this type? Volume ratiossuch solutions depend primarily on the properties of the clay mined in a particular area. The fatter it is, the more sand you need to pour into the mixture. The suitability of such a mortar for masonry is checked in a fairly simple way. To do this, first make small portions of mixtures in different proportions. Next, a ball is rolled from each of them and thrown from a height of 1 m. A solution is considered suitable that does not crack during such a test.
