Marking of concrete and products from it: we learn to read
Deciphering the marking of concrete, as well as products based on it, is very important for those who plan to build independently. To understand all the intricacies of the nomenclature is at least because this way we can save time on the selection of suitable materials, and reduce the risk of buying not what we need.
In our article we will provide information on the most common notation, as well as a number of tips on the use of certain materials.
Concrete and its types
Material grade
Concrete itself, which is used to solve a wide range of engineering problems, is characterized by two indicators - brand or class. Both of these indicators are interdependent, and therefore can be used in parallel. To navigate in a variety of materials, it is worth studying the basic principles on which gradation is built.
Brand is an indicator that corresponds to the average value of concrete compressive strength, expressed in kgf / cm2.
Note! The mark is calculated for a material that has hardened for 28 days under optimal conditions.
Бетоны разных марок по ГОСТу обозначаются индексами от М50 до M1000. Примеры использование наиболее распространенных типов мы приводим в таблице ниже:
| Material | Features of use |
| M100 | It is used in foundation work as a footing: it is poured onto dirt substrates for their leveling and preparation for laying the base layer. |
| M200 | One of the most commonly used brands. It is used for filling floors and screeds, in the formation of foundations, pavings, laying tracks, etc. Also on the basis of this material are cast products, such as lightly loaded stairs, lintels, struts. |
| M250 | Differs in greater durability, than the previous version. It is used for the formation of capital foundations of the monolithic type, as well as for the manufacture of floor slabs that experience a low operating load. |
| M350 | In the production of reinforced concrete products instruction recommends the use of this particular brand. M350 concrete slabs are cast, lintels, beams, piles, pavement elements, etc. |
| M400 and M450 | This material is characterized by the highest strength. It is involved in the construction of hydraulic structures, supports, columns and other structures experiencing increased loads. |
| M500 (sometimes M550) | The most durable compound of those used in mass construction. The main purpose is the construction of supports and walls with increased requirements for reliability. After solidification, it is practically impossible to process, if necessary, only cutting of reinforced concrete with diamond circles is used. |
As you can see, a variety of materials is quite large. It should also be noted that concrete should be chosen in strict accordance with the task, since the price of different brands differs quite significantly.
Material class
Параллельно с маркой используется также обозначение класса бетона (читайте также статью «Антисептик для бетона: особенности выбора и применения»).
Class is a characteristic of the strength of the material, which is provided with a probability of at least 95%. For example, the material designated by the B20 index must withstand a load of 20 MPa.
As we noted above, brand and class are related.
If you want to transfer one indicator to another with your own hands, you should use the formula:
B = (M * 0.79) / 10, where:
- B - material class.
- M - brand of concrete.
For more convenience, a table has been developed which indicates the compliance of the class of cement and the closest grade. A fragment of this table with the most frequently used species is given below.
Reinforced concrete products and their nomenclature
In addition to concrete itself, products based on it are also labeled.
Most often for their designation are used alphanumeric indices:
- A combination of two or three letters indicates the type of product and its configuration.
- The figures show the linear dimensions of the object: length, width (sometimes section) and height. The most commonly used values are in decimeters - for example, this is how marking of reinforced concrete piles is carried out.
- Slab plates are a little differently. In addition to linear dimensions, they indicate the calculated load on the product in tons.
- The marking of reinforced concrete lintels also has several differences. In addition to linear dimensions, the marking also indicates the permissible load on the part, and before the letters is given a digital index showing the type of cross section.
Note! If a crane is used to transport the bridges, it is very important that there are loops on each product. This is evidenced by the letter index "P", which is placed after the numerical designations.
The main types of products, their indices and characteristics are given in the table below:
| Product group | Main varieties and their labeling |
| Foundation blocks | · Solid - FBS. · With cut-out for jumpers or communications - FBV. · With voids at the bottom - FWP. |
| Piles | · Square solid - C. · Square hollow - SP. · Round - SK. · Piling shell - WITH. |
| Floor slabs | · To overlap tunnels and channels - PT. · Flat - TAP. · Threaded - PPP. · Lightweight - PBO. |
| Road slabs | · Standard - PDP. · Tensioned - PDN. · Corrugated - PDG. · Aerodrome with surface corrugation - PAG. · For permanent roads - 1P. · For temporary pavements - 2P. |
| Jumpers | · Facade - PF. · L-shaped beams - PG. · Squared - PB. · Slabs - PP. |
Naturally, here is information only on the most common products and their main types. The nomenclature of reinforced concrete structures is very extensive, and therefore, before starting work, you should carefully study the entire available range.
Conclusion
Приведенная выше маркировка железобетонных изделий, а также информация о марках и классах растворов, применяемых в строительстве, являются весьма полезными для начинающего строителя. И даже если вы не планируете проектировать сооружение сами, полученные знания помогут вам проконтролировать работу нанятых специалистов (см.также статью «Удобоукладываемость бетонной смеси: нормативные документы, марки, методы испытаний»).
So you should carefully examine all the data presented, as well as view the video in this article.