Dear readers of Stroy-shkola.ru, kind time of the day. In this article, we will analyze which reinforcement to use for the foundation, as well as find out the types of reinforcement and which reinforcement is best suited for different types of foundation and concrete.
Which reinforcement to use for the foundation of
Concrete is an old invention, its variants were used in the Ancient World. However, the concrete casting, despite its good resistance to compressive loads, has insufficiently acceptable parameters for resistance to loads in other directions.
Meanwhile, concrete structures, especially concrete castings, which underlie various foundation structures, can be subjected to impacts in other directions. On the concrete concrete foundation, on a concrete foundation in the form of a monolithic slab, on a driven pile or on a bored pile, not only the weight of the structure itself but also the efforts of the soil, which varies in volumes, are affected by seasonal changes. In most of our country the soil freezes in winter and the moisture contained in it expands the volume of the soil. The expansion occurs in all directions and the foundation base can be subjected to horizontal loads. Also, the soil on your building site can consist of several layers of different density, which can move relative to each other.
Types of reinforcement for foundations
- Metal reinforcement for the creation of a power frame of concrete foundations is a steel rod. The most common are metal bars, which have a circular shape in section. To increase the strength characteristics, the surface of the metal rod is provided with a ribbed screw surface.
- In addition, recently the armature for concrete castings can be made of durable fiberglass. Manufacturers indicate that fiberglass reinforcement can exceed the density of metal rods.
Fiberglass reinforcement - photo
The main characteristic of the fittings is its cross-section or diameter. The construction industry produces metal fittings with a diameter of 5 to 32 millimeters. Thus, when designing a metal frame, it is possible to select a steel reinforcement with a section providing the necessary strength of the entire structure.
In case of individual construction, in the creation of foundation foundations, reinforcement is usually used and a cross-sectional diameter of 8 to 16 millimeters.
For each type of foundation: tape, monolithic in the form of a plate or bored pile diameter of the reinforcement is selected individually.
In addition, metal fittings, regardless of its cross-section, can be divided into two main types:
- With a ribbed surface. Such fittings should be used in areas where tensile loads will occur. The ribbed surface of such a reinforcing bar shows a higher degree of engagement with the solidified concrete mortar, since it enters into contact with it on a larger surface.
- Rods with a smooth surface. Such fittings are usually used as connecting bridges. Thus, it should not have major loads, and smooth metal fittings can connect longitudinal lines of force made of ribbed metal fittings.
How to connect reinforcement to the foundation
In industrial construction, metal bars of the armature are usually connected in a single frame by means of point-wise electric welding. This allows you to fix the intersection of rods with high speed. However, this method also has its limitations:
- First, all types of metal fittings can not be welded together, but only one that has a "C" - "welding" beech in its marking.
- In addition, welding of metal bars of reinforcement bars is a rigid means of fixing, but the power frame must have a small degree of freedom in the intersection of rods. Meanwhile, the welding fixes the rods without play.
- Another disadvantage of welding the reinforcement is the loss of the strength properties of the metal rod at the welding site.
Also a popular method of joining metal bars of reinforcement in the places of its intersection in the frame is knitting. It is carried out with the help of a knitting wire, from which loops are formed and twisted at each intersection of metal bars of the frame.
A fresh way to fix the intersection of metal rods is the use of plastic construction yokes. This is a very fast way of fixing, and also relatively cheap.
The binding of the fittings - photo
When joining the wire rods in the corner parts of the foundation, they must be overlapped, with the rods bent, without their simple crossing. Read the article - how to tie the reinforcement for the foundation.
We use reinforcement when erecting the foundation foundation
When creating monolithic concrete foundation foundations, it is recommended to create at least two horizontal reinforcement levels. In this case, no part of the reinforcement belt should touch the surface of the formwork, and, accordingly, the surface of the future concrete casting.
In each of the horizontal reinforcing belts of the belt foundation there must be at least two longitudinal lines of force, made up of ribbed reinforcement. Between each other, the longitudinal lines and horizontal layers are connected respectively by horizontal and vertical power bridges, for which a cheaper reinforcement can be used that is cheaper and smaller in section.
For the frame of the ribbon foundation for a private house, the step between connecting bridges can be about 50 centimeters.
. On all sides, the power frame of the strip foundation must be surrounded by concrete. The protective layer should be at least 5 centimeters. But do not heavily bury the horizontal power belt in the concrete casting - in fact it performs the role of a metal beam and protects the casting from damage during its bending.
At the bottom of the concrete belt, the distance from the power belt to the outer edge of the casting can be 3 centimeters.
We create a reinforcing frame in bored piles
For reinforcing bored piles we use a metal ribbed rod with a cross section of about a centimeter. To reinforce the piles, you can apply from 2 to 4 or more vertical lines of force. The final number of vertical rods in the cast depends on the diameter of the future pile.
Scheme for reinforcing bored piles
The diameter of the bored pile is regulated by formwork. In its quality it is possible to use pieces of pipes from almost any material. So when using asbestos cement pipes with a diameter of 20 centimeters, you can use 4 twins of a centimeter section.
As well as the concrete concrete foundation, the metal reinforcing bars must be completely covered with concrete and do not touch the walls of the formwork.
Reinforcing the concrete foundation in the form of a solid
slab The creation of a monolithic concrete base in the form of a slab is one of the most expensive, but at the same time one of the most reliable solutions. In this case, a large number of reinforcement will be used in such a foundation.
Reinforcing the concrete foundation in the form of a solid plate
For such a foundation, a reinforcement with a cross section of 10 to 16 millimeters is used. When viewed from above, two horizontal force reinforcing belts should form cells with dimensions of 20 to 20 centimeters.
