Brick is a very popular building material, which can be used for the construction of buildings and structures of almost any purpose. Dwelling houses, production halls, pavilions, fences, etc., erected from such ceramic stone, are distinguished by their durability and excellent performance characteristics. Bricks are fastened in the masonry during the construction of walling, foundations, etc. with solutions of a special kind.
Such mixtures are made, of course, with the exact observance of certain rules. In case of violation of the established technologies for their kneading, a strong structure will not work and will not last for a long time. Simply put, the brand of mortar for masonry should be chosen correctly.
Application features
The technology used in the construction of brick structures is approximately the following:
On the previous row, the masonry mortar is usually spread with a layer of usually 1 cm. The row length of 4 bricks is captured.
The solution is leveled and removed with the edge of the trowel starting from the front side.
The removed solution is superimposed on the brick, which is then pressed to the previous one and tapped with a mallet.
The thickness of the vertical seams in such a masonry is usually equal to 0.8 cm. The joint stitching using this technology is carried out immediately.
Sometimes a slightly different technique can be used for masonry. In this case, the solution is spread over a number of thicker layers. In this case, the laid brick moves to the previous one with the capture of the mixture. The latter, when applying such a technique (“clamp”), forms a vertical seam.
Which masonry mortar works best: requirements
After setting, the mixtures used in the construction of buildings and structures should not:
The following requirements are imposed on the masonry mortar itself:
high adhesion to bricks;
quick set of strength;
plastic.
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 will significantly slow down the construction of the building. Brick, as you know - the material is heavy. And several rows of masonry that did not have time to harden the liquid solution will simply crush.
It will slow down the construction of a brick structure and the use of a rigid inelastic mortar. It will be difficult for the master to lay a stone on such a mixture. In addition, the use of inelastic mortar will ultimately negatively affect the quality of the brick structure itself.
Varieties of mixtures
There are two main types of brick used for the construction of buildings and structures of brick building compounds:
The first type of mortar for masonry joints at the same time among builders is most popular and is used very widely. For example, it is these mixtures that are used in the construction of walls of residential low and multi-story buildings, partitions, fences, foundations.
Special solutions are prepared using special additives or high grades of cement, giving them the properties necessary in this particular situation:
Mixtures of this variety can be used, for example, for the construction of walls of production shops, chimneys, foundations.
Main components
Brand cement mortars for masonry can have different. But in any case, such mixtures necessarily consist of two main components:
In the production of universal masonry mortar, and often special, 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.
Requirements for the main components
Sand in the manufacture of masonry mixtures is usually used large river. Career material of this type can also be used, but only when erecting the walls of low-rise private country houses.
The brand of mortar for masonry, among other things, depends on the brand of cement used for its manufacture, as well as its amount in percentage terms. Such material differs primarily in the degree of strength after solidification.
Cement of low grades is used for the construction of non-loaded structures that are not exposed to negative environmental factors. More durable material is used for the preparation of mortars intended for the construction of walls, 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, in the construction of any structures, air materials of this variety can also be used. 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 kneading compositions intended for the construction of structures that are exposed to high temperatures during operation. It can be, for example, chimneys, stoves, fireplaces. On lime and gypsum, masonry mortars for bricks are extremely rare. Such mixtures are considered much warmer than cement. However, they also differ in lower strength. Such compositions can be used for laying only unloaded, insignificant structures inside buildings.
What supplements can be used
Universal solutions 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, a cement mortar with the addition of lime as a plasticizer can also be mixed. Such a mixture is practically not inferior to the usual strength. Moreover, it is more elastic, which facilitates the work of the master. The main disadvantage of mixtures with the addition of lime is considered a lower degree of resistance to moisture.
In some cases, special polymer substances can be used to increase the elasticity of the solution. But such additives usually are, of course, only part of the factory dry masonry mixtures. In the preparation of solutions with their own hands directly at the construction site, lime is used in most cases as a plasticizer.
The same clay is usually used as a refractory additive in the manufacture of special masonry mortars. Sometimes such mixtures are also made using fireclay chips. Also, when preparing masonry mortars, additives can be used:
Grades of solutions for masonry in accordance with GOST
The properties of the mixtures used in the construction of buildings and structures, as already mentioned, depends primarily on the brand of cement and the proportion of the mixing of the components. The degree of strength of a solution and its purpose can be determined, first of all, of course, by its brand. The table below shows the dependence of the latter on cement consumption in kilograms per 1 m 3 of sand / mortar according to GOST.
Cement / mortar grade | 150 | 100 | 75 | fifty | 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 brand of cement mortar for masonry primarily its compressive strength.
Mixtures for this indicator are selected according to a rather 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 when using, for example, M150 stone - this is M50 or M75, depending on the significance of the structure being constructed.
Observe this rule when buying and manufacturing masonry mortar is necessary. Cement mix and brick have different degrees of water absorption and strength. Therefore, there is some contradiction - the stronger the solution, the weaker the masonry. A brick may simply not withstand the shrinkage stresses of a strong mixture, which will lead to deformations and tears.
Thus, a mixture is selected for the ceramic material, depending on the degree of structural loading. For example, people who decide to build a house on their suburban area are interested, among other things, and what brand of mortar is suitable for the brickwork of external walls. For the construction of structures of this type can be used ceramic stone from M75 to M200. Accordingly, the mixture is used grades 50-100.
Mobility
The quality of the masonry also depends on how evenly the joints in it are filled. To prevent air voids between the bricks, the mortar must be distinguished by a certain degree of mobility. This indicator in the mixture depends on the percentage of components, as well as their characteristics.
Marks of mortars for masonry on this indicator, there are only 4 - from Pk1 to Pk4. It's believed that:
Pk1 mix is great for vibrated rubble masonry;
Pk2 - for not vibrated;
Pk3 - for hollow bricks and ceramic stone;
Pk4 - for pouring voids in the masonry.
What rules should be followed when cooking
What brand of mortar for masonry is suitable in one case or another, 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 properly prepared. 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 of both finished dry formulations and individual components, it is important to achieve its complete homogeneity. More recently, such solutions were kneaded in troughs or on sheets of iron, using shovels and choppers. But today, in most cases, even the owners of small cottages have special equipment available for the manufacture of masonry mixes as well. Nowadays, owners of suburban areas in concrete mixers make solutions. Using such equipment, the finished mixture, due to its homogeneity, is obtained of the highest quality.
To put in the hopper concrete mixer relies first dry mortar components. After mixing them for several minutes, such equipment is turned off. Then 75% of the required amount of water is poured into it. In the next step, the solution is mixed for another 5 minutes. The remaining water is added to it after it has been moved from the hopper of the concrete mixer to the masonry tank.
Cement before preparing the solution does not, of course, require any special preparation. The only thing - before using this material for kneading, you must definitely look at the release date. It is impossible to use stale cement for masonry. For example, six months after the release date, the strength of this material decreases several times. Accordingly, the brand of cement-sand mortar for masonry prepared from it is also reduced.
Keep this material, of course, need to be in a dry place. In the USSR, firing produced very high-quality cement, lumps of which, if wet, could be broken and used safely for masonry or pouring concrete structures. Modern material of this type is made using special chemicals. The quality of the Soviet, as many masters believe, is inferior. Therefore, unfortunately, it is impossible to use modern Portland cement, which has become clutching.
Sand before kneading mortar for bonding masonry should be sieved. Ultimately, no organic impurities or debris should remain in it.
Number of ingredients
The grade of brickwork mortar prepared in the factory is usually simply indicated on the packaging. When mixing such compositions directly at the construction site, the components are combined in certain proportions by volume.
When preparing a mortar for masonry, the cement / sand proportions are usually used as follows: 1/2, 1/3, 1/4 or 1/5. Plastic solution is done in most cases the same. The most popular mixture of this variety among masons is cement / sand / lime, prepared as 1/5/1.
All components are placed in a concrete mixer in such quantities that the solution yield is not too large. It hardens the cement masonry mixture within about 2-2.5 hours. That is, in 1-1.5 hours, the portion prepared in the concrete mixer must be worked out necessarily.
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 how to make refractory compositions of this type? The volumetric ratios of such solutions depend primarily on the properties of clay extracted in a particular area. The fatter it is, the more sand you need to pour into the mixture. Check the suitability of such a mortar for masonry in a fairly simple way. To do this, first make small portions of the mixtures in different proportions. Then a ball is rolled from each of them and thrown from a height of 1 m. A solution that does not crack during such a test is considered suitable.