Before considering the issue of the proportions of cement mortar, you still need to clarify the issue of the solution itself. With any individual construction people use cement solutions, while using cement and sand. However, unlike professionals, many simply do not understand that cement mortar and concrete mortar - things are somewhat different, that's why they are used differently.
Difference between cement mortar and concrete mortar
The fundamental difference between these solutions is that if only sand is used for the cement slurry, in addition to the cement itself, gravel( or crushed stone) is also used for concrete mortar. The conversation will be about cement mortars. Therefore, in the first approximation, we can say that a concrete solution is a "fine-grained" cement mortar. For each "type" of work, a composition is prepared. This is due to the purpose for which it will be applied.
Each "construction" is operated( or will be operated) under certain conditions. Therefore, the conversation should still not be about the cement brand, which is "kneaded", but about the brand of the cement mortar, which should result in the result. The grade of the solution is an indicator of the hardness, strength and durability of the finished "design".After all, you need to take into account such parameters as climatic conditions, temperature drops, humidity, pressure. It is also important whether this place of solution laying will subsequently experience any loads.
Any cement slurry consists of two components - cement and sand - "mixed" in water. The technology of preparation of all similar solutions is the same. First of all, a dry mix is prepared, consisting, of course, of sand and cement. The difference between brands of cement mortars is that for each of them a certain brand of binding agent( cement) is taken. The second difference is in the proportions in which the components are taken. In other words, what is the ratio between the mass of cement and the mass of sand.
Kinds of solutions
Solutions are divided into fatty, lean and normal. Oily differ from the norm by a large amount of cement. Their shortcoming is rapid cracking. In the solution, the excess of sand is scrubbed, it is difficult to work with it, and its strength is not high. When carrying out construction work, as a rule, cement mortars of grades 15, 50, 75, 100 and 150 are used.
Assignment of solutions and proportions of different brands of cement
Cement solutions are plaster, masonry and building. They differ in the quality of the sand used and in the sand-cement mass ratio. For plastering walls, for example, sand is fine-grained.
In practice for private construction a solution is prepared such: 1 part of cement for 2 - 3 sand. In this case, the cement should be used 300 or 400. If there is more sand, then in the future premature destruction of the masonry is possible.
Solution grade 100
If sand is taken fine, it is well suited for plastering and masonry work. If the cement grade is "400", then the sand is 3.5 parts. And if the cement "300" - 2.5 parts. You can use granite dust instead of sand. The ratio is 1: 3 with cement "400".
Mortar grade 150
Also suitable for masonry and plaster. If it is necessary to make a floor screed, the sand should be coarse-grained.
It should be borne in mind that very often different fillers are used. The addition of gypsum, hydraulic lime, clay to the solution increases its elasticity.
