Contents
In private housing construction, concrete is used everywhere. Foundations, blind area, paths are made from it. Often, concrete grade B15 M200 is used for these purposes – this is the best option in many cases.
Materials
Concrete brand B15 M200 can be called one of the most widely used in private construction. Foundations are made from it for one-story buildings, if a large load is not expected. It is used when pouring garden paths, other concrete work that is carried out on the farm.
According to the new classification, concrete is characterized by compressive strength. Mark M 200 corresponds to class B15. This means that this concrete stone, after gaining design strength, will withstand a load of at least 150 kg / cm². Such strength is more than enough for any one-story house or house with an attic.
Frost resistance – the ability to endure freezing / freezing cycles without damage. It has concrete M200 about 100 cycles. Another important criterion is water resistance. This is the ability to resist water penetration. Mark M200 belongs to the category of materials with normal permeability. If water protection is important to you, look towards higher brands.
Two other parameters – mobility / stiffness and density, are determined by the selection of gravel and the amount of water. Proportions are usually given “average” for average parameters. But you have to be very careful when changing them. Even a small deviation can greatly affect the result. By pouring a couple of glasses of water onto one concrete mixer, you risk getting a solution that is too thin, which can lose strength.
The weight of a cube of M200 concrete in a liquid state is about 2362 kg / m³, in a dried form, the mass of one cubic meter is 2162 kg / m³. These are average values, since the specific mass depends on the density, the use of additives and other factors. Differences can be about 4-6% of the above figures. So you can look at these numbers as well.
Application area
From the listed properties follows the scope of concrete grade B15 M200. The main thing you should pay attention to is the water resistance. This may be important when pouring the foundation in conditions of high groundwater levels. In this case, it is better to choose a water-resistant composition. The rest of the area of u200buXNUMXbuse of concrete MXNUMX is as follows:
- In the production of reinforced concrete foundation blocks.
- Flights of stairs, other elements of stairs.
- Floor slabs.
- Paving slabs.
- Pouring concrete paths.
Most often, concrete of this brand is used for the strip foundation. - Strip foundations for one-story houses.
- Fence foundation.
- Screed (with a thickness of 5 cm with crushed stone of fine fraction).
Depending on the thickness of the required layer, the size of the aggregate is selected – crushed stone. The maximum particle size should not exceed half the layer. Therefore, concrete of the M200 grade is coarse-grained and fine-grained. In the first variant, gravel is used in large size, in the second, small.
Composition and proportions
Like all others, concrete grade B15 M200 consists of a binder – cement, aggregates – sand and crushed stone. All these components are mixed and diluted with clean water to the state of batter or thick sour cream. In general, the density can be different depending on the requirements. For example, in formwork with reinforcement, a more fluid composition is needed, since the solution must fill the space between the reinforcing bars.
Only dry ingredients are given in the tables. Water is added based on the required hardness of the solution. The average water-cement ratio is 0,6. This means that water should be taken 0,6 by weight of cement. To put it simply, add 1 ml of water per 600 kg of cement. To begin with, it is worth measuring this amount. Half is added to the concrete mixer at once, then in small portions to the desired consistency. As a result, there may be a little more or a little less water. Even the humidity of the sand affects its quantity.
The composition of concrete grade 200 in the table is given both in mass fractions and in volume. When purchasing, it is more convenient to operate in kilograms, and they usually fall asleep in a concrete mixer with buckets or shovels. This is where volume fractions come in handy.
Consumption of components per cube of concrete
When purchasing materials for concrete, first determine how much mortar is needed, and then consider materials for it. Sand and gravel can be taken with some margin – they are still needed for backfilling, other construction work. Although, if you look at the average, 200 kg of crushed stone and 1060 kg of sand go to one cubic meter of M900 concrete.
Cement is better to take “to spare.” This material significantly loses its strength during long-term storage. So, three months after the date of production, its strength becomes 20% lower, six months later, the loss is 30%, and a year later, 50%. So, firstly, you need to buy fresh cement, and secondly, it’s better not to take too much.
To find out how much cement you need for work, multiply the number of cubes by the consumption rate. Available in kilograms or bags. But keep in mind that packing can be both 40 kg and 25 kg. So the figure in kilograms should be remembered. In conclusion, a video about the composition and mixing of concrete M200: