How many fittings on 1 m3 of concrete for the foundation: cost, norm
When building large industrial and residential buildings, the question is, how many fittings are needed for pouring 1 m3 of concrete, does not occur: its consumption rates are regulated by the relevant GOSTs (5781-82, 10884-94) and first laid in the project. In private construction, where few people pay attention to the requirements of regulatory documents, adhere to the norms of consumption of reinforcement products should still be, as it will allow to create reliable concrete designs, which will serve you for many years. To determine such rules, you can use a simple technique, which allows you to calculate them using simple calculations.
The reinforcing frame directly determines the performance characteristics of the foundation
The use of reinforced concrete structures in private construction
Cement, as everyone knows, is the material, without which it is impossible to do in construction. The same can be said about reinforced concrete structures (ZBK), created by reinforcing the cement mortar with metal rods to increase its strength.
As capital, and in private construction can be used and monolithic and prefabricated reinforced concrete. The most common types of the latter are foundation blocks and ready-made floor slabs. As examples of monolithic structures, made of reinforced concrete, it is possible to result the pouring base of tape type and cement couplers, which are pre-reinforced.
Construction of strip foundation
In those cases, when construction is carried out on site, where it is difficult to supply the crane, floor slabs can also be made in a monolithic way. Because such RCCs are very responsible, then when pouring them should strictly adhere to the consumption of reinforcement per cube of concrete, stipulated in the above regulations.
Installation of reinforcement structures in private construction is best done with a knitting wire made of steel, as use for these purposes of welding can not only worsen quality and reliability of the created framework, but also to increase the cost of work performed.
An expensive rebar gun has been successfully replaced by a homemade hook, bent from a wire and fixed in the chuck of the screwdriver
How to determine the consumption of fittings
Consumption rates of reinforcing elements, calculated per m3 of reinforced concrete structures, depend on a number of factors: purpose of such structures, used to create concrete cement and additives, which are present in it. Such norms, as mentioned above, regulated by the requirements of the Guests, but in private construction it is possible to be guided not by this regulatory document, and on the State elementary budget norms (GESN) or at Federal unit rates (FAIR).
So, according to GESN 81-02-06-81, for reinforcement of the monolithic base of general purpose, the volume of which is 5 m3, need to use 1 tons of metal. The metal, by which is meant the reinforcing frame, should be evenly distributed throughout the concrete. In the collection of FER, in contrast to GESN, the average consumption of fittings per 1 m3 of concrete is given for structures of different types. So, for FER, for reinforcement of 1 m3 of three-dimensional foundation (to 1 m in width and up to 2 m in height), in which there are grooves, glasses and subcolumn, necessary 187 kg of metal, and for concrete structures of flat type (example, concrete floor) – 81 kg of fittings on 1 m3.
Estimated weight 1 m of steel reinforcement
The convenience of using GESN is, that with the help of these standards you can also determine the exact amount of concrete solution, using coefficients, taking into account the difficult to overcome waste fittings, which will be contained in such a solution.
But, Of course, determine the exact number of fittings, which you need for concrete foundation or flooring, allow the above Guests.
Minimum standard diameters of fittings
Parameters of armature depending on its diameter
Number of reinforcement to strengthen the foundation
To determine the number of fittings, which is necessary to strengthen the concrete, the following data must be taken into account:
- type of foundation, which can be columnar, plate or tape;
- foundation area (in m2) and its height;
- diameter of reinforcing bars, as well as their type;
- soil type, on which the building is erected;
- total weight of the building structure.
The principle of reinforcement of the strip foundation
For reinforcement of the bases of plate and tape types products with a ribbed profile of a class A-III and the sizes of cross section not less are mainly applied. 10 mm. As elements for connection of frame lattices use of armature of smooth type and smaller section is allowed. Concrete of the monolithic base for heavy buildings is reinforced by bars of bigger section - 14-16 mm
The reinforcing frame consists of lower and upper belts, in each of which the rods are stacked as follows, that the size of the formed cells was approximately 20 div. The belts are connected by vertical rods, which are fixed by means of a knitting wire. The height and area of the foundation will allow you to determine, how many meters of reinforcement you need to strengthen the concrete. Knowing the cost of fittings on 1 m3 of your reinforced concrete, you can choose the size of the cross section of the rods, which will depend on the thickness of the foundation.
Layout diagram of the strip foundation reinforcement
Once you determine, how many fittings you will need, you have to distribute the structure from it this way, to on 1 m3 of concrete had the required amount of metal mass. Creating a reinforcing frame, you should pay attention to that, that all its elements were covered with a layer of concrete not less than thickness 50 mm
Identify, how much reinforcement is needed to strengthen the strip foundation, a little easier, than for more massive concrete structures. In this case, you should also follow the rules, stipulated in FER - 81 kg of metal per 1 m3 of concrete mortar. It is necessary to be guided by the sizes of the tape base. Example, if its width does not exceed 40 cm, then two rods with a cross section can be used to form one reinforcing belt 10-12 mm. In accordance, if the width is greater, then the number of reinforcing bars in the row should be increased.
Estimated cross-sectional areas depending on the number of rods
For foundations, the depth of which does not exceed 60 cm, the reinforcing framework is created from two levels. If the depth is greater, then the number of frame levels is calculated as follows, so that they are located at a distance 40 see each other. To connect the reinforcing belts together, as mentioned above, vertical jumpers are used, which are mounted along the entire length of the frame, arranging them with a step 40-50 div.
Methods of reinforcing corners
Having made a simple drawing of your future reinforcing frame and putting all the dimensions on it, you can easily calculate, how many meters of rods of a certain diameter you will need. Calculating the total length of the rods, you will need to divide it by the standard length of the reinforcement (5 or 6), and you will learn, how many such rods to buy.
If you are going to pour a strip foundation for easy construction, and the soil on your site is solid, then to strengthen the concrete you can use reinforcement with a diameter of up to 10 mm, creating a framework from it according to the method described above.
