Concrete M300, like any other, in principle, is a practically universal material that is currently used in many areas of construction and for a variety of purposes. Each brand of this substance has its own properties, price, characteristics, production technology.
general information
M300 is a brand that is considered almost universal, as it has an acceptable cost and fairly good properties. In addition, the parameters of the concrete mixture are determined in advance by GOST. Of course, in order to obtain high-quality concrete M300 as a result, it is necessary to use good starting materials. But here it is important to note that the composition of this substance includes as many as five different components.
Production Components
Naturally, the main ingredient is cement. As a rule, brands M400 and M500 are used, since they are characterized by the best properties. The use of the M200 brand is impractical, since this can degrade the parameters of the finished concrete. Due to the fact that the cement elements of the M200 are poor in performance, in the future it will not be able to withstand the required loads.
By the way, when buying, it is very important to pay attention to the expiration date. If it has expired, then the quality of M300 concrete, like any other, will noticeably decrease.
The second element is crushed stone. Most often, granite, limestone or gravel is used here. It is worth noting that the granules can vary greatly in size: it can range from 5 to 70 mm. The choice of this filler is based on an indicator of its strength. It should be twice the strength that will be required from concrete. In other words, the composition of concrete M300 with limestone will be 500-600, and with gravel - 800-1000.
If you follow this rule, then in the future it will be possible to avoid the destruction of the structure. It should be added that if the gravel is contaminated, it will have to be washed before being added to the composition.
M300 concrete also contains sand. This grade of material implies the presence of sand granules ranging in size from 1 to 2.5 mm. In order not to worsen the performance of the future solution, sand also needs to be sifted if it contains dirt particles.
Oddly enough, water is an essential component that affects the quality of concrete. So, if you use chemically or biologically contaminated liquid for mixing, then its properties will deteriorate. Filter water before use.
The last element that has a significant impact on the performance of M300 concrete is additives. We are talking about various plasticizers and other ingredients that are added to the material if necessary to increase its frost resistance, for example, or other technical indicators.
Characteristics of the substance
As it has already become clear, the quality of the M300 depends primarily on the components used. When applying quality components, the characteristics of concrete will be approximately as follows:
- Water resistant - w8. This indicator says that we have a low permeability composition. Moisture absorption does not exceed 4.2% of the volume.
- The level of frost resistance is f200.
- Concrete of this brand belongs to class b22, however, b25 is also often written. Depending on the requirements for future construction, the mobility class of the composition may vary from n2 to n4.
- The density of concrete M300 is 1800-2500 kg / m³. This parameter will vary depending on the type of filler used.
- Stiffness - 2-4.
- This concrete belongs to the class of heavy.
Application
Due to the fact that concrete M300 has quite good properties, which can also be adjusted by changing components, this composition has found wide application in construction works:
- It is used for the construction of facilities such as sites, roads, borders, as it withstands high loads and does not crumble.
- With its help, walls or supports are installed.
- They are used in the construction of stairwells in apartment buildings, as well as for the stairs themselves.
- It is great for pouring a monolithic foundation, on which a multi-storey building can stand, while not settling under pressure.
- It is used for the production of reinforced concrete products, as well as fences.
It is also worth adding that this concrete is well suited for the construction of sewer pipes that are constantly exposed to high humidity, as well as being in conditions of constantly changing temperature.
DIY Components
You can purchase a ready-made solution, but you can produce it with your own hands. If you make the M300 yourself, then you need to know that it can be of two types:
- The first involves the use of cement grade M400. In this case, the ratio of such components as cement, sand, gravel will be as follows - 1: 1.9: 3.7.
- The second type means that you have to use cement M500. Here, the ratio of components will change and will look like this - 1: 2.2: 3.7.
Production
The weight of concrete M300, or rather one of its cube, can reach 2000 kg / m³. The recipe is quite simple, and for successful production you will need only the material itself and some devices. So, to get one cube of M300, you will need:
- from 340 to 360 kg of cement;
- 800-850 kg of sand;
- 900-1100 kg of crushed stone;
- about 200 liters of water;
- approximately 10 kg of various additives (plasticizers and other).
To produce such an amount of material, a concrete mixer will naturally be needed. In addition to it, a shovel is necessary for loading dry components, buckets for pouring water, as well as measuring tanks, so that it is possible to observe the proportions of concrete M300.
Manufacturing technology is quite simple:
- The first thing to do is pour 3/4 of the total volume of water into the concrete mixer.
- After that, the equipment turns on and you can begin to fill up the cement.
It is necessary to mix water and cement until a homogeneous mass is formed, only then you can add crushed stone first, and then sand.
Specific gravity and dry matter producers
In order to successfully carry out any work in which you want to use concrete, you need to know its specific gravity, as this will help determine the required number of source components. For example, if you take the numbers given in the previous description and mix the solution with their help, you get a cube with a specific gravity of about 2400 kg. In this case, to create concrete M300, the consumption will be about 30 bags of the mixture.
Of course, professional builders do not use this, but this will help with homework. It is also worth adding that the specific gravity includes the weight of the reinforcement, if any, as well as the location of the mortar.
To date, there are dry mixes, which are often referred to simply as sand concrete. It is important to note here that it was the recipe for the preparation of concrete M300 that gave impetus to the development of such a substance. It is packaged in bags with a weight of 25 to 50 kg. True, the cost per bag will exceed the cost of the same amount of M300 by about 150 rubles. However, using sand concrete is much simpler and faster. In addition, the addition of crushed stone to it, if necessary, is also allowed.
Hardening Features
Due to its characteristics, concrete M300 during hardening is characterized by specific reactions. So, if the proportions were chosen correctly, then crystalline hydrate occurs during this process. At this time, in fact, the interaction of cement and liquid occurs, which is accompanied by the formation of a new substance. This is very important to know, since if there is too little liquid in this period of time, the process itself will take longer and the final strength of the concrete will decrease. In some cases, it may even shrink or crack.
If the ambient temperature is high enough, then humidification should be started no later than two hours after pouring. In the normal temperature range with sufficient humidity, this parameter can increase up to 12 hours.
It is important to note here that it is only necessary to water concrete with a spray, so as not to damage the weak surface with a jet. Knots and faces of the structure should be watered more carefully than just a flat surface.