The base of the foundation performs the important tasks of receiving and distributing the load coming from the building frame. In most cases, a concrete pad is used for the load-bearing part, which is arranged in various configurations on the job site. But in itself, such a foundation is unreliable, and as an additional reinforcement, reinforcement of the foundation with special rods is used. Metal rods hold the concrete slab together, giving it high strength and resistance to natural destructive processes. Accordingly, the reliability of the building as a whole will depend on the quality of the reinforcement, therefore, during installation activities, it is important to follow the technical instructions.
Required tools and materials
The foundation itself is made of M250 cement, sometimes with the addition of crushed stone, and medium fraction sand will act as the basis. Work operations may require the use of an angle grinder,shovels and pliers. Mostly the tool will be used when processing the reinforcement itself.
To prepare cement, you will also need a container, an electric mixer and a construction sieve. Particular attention is paid to the choice of rods. In capital construction, steel rods with a smooth or corrugated surface are used. Thus, the reinforcement of the foundation of a multi-storey building is carried out with smooth rods, and crescent-shaped rods are used for cottages. A universal option for low-rise construction will be reinforcement with an intermittent ribbed surface. This option is beneficial in that it provides good adhesion regardless of the type of concrete base and the design of the carrier pad.
Preparation for work activities
The work site is freed from unnecessary building materials, equipment and consumables. At this stage, it is important to prepare and clear the area specifically for the future pouring of the foundation. If you plan to use a power tool, then a power supply system must be provided. Alternatively, a battery-powered device that does not require a direct connection to the mains may be suitable. In order for the reinforcement of the foundation with reinforcement to turn out to be of better quality and more durable, it is necessary to initially degrease and dry the surfaces of the rods. They should be free of foreign particles and peeling coatings. Corroded elements should be discarded and replaced with new, clean fittings.
Calculation of foundation reinforcement
At this stage, the number of rods is determined,which will be used during the strengthening of the structure. But before that, you should take into account several requirements for the frame parameters:
- A square cell of the reinforcement mesh should have dimensions from 20 to 30 cm.
- If the length of the section exceeds 3 m, the diameter of the rods must be at least 12 mm.
- The transverse bars are selected with the expectation that their length will be 100 mm shorter than the formwork width. This is necessary to ensure a free fill around the edges.
- If the frame height exceeds 80 cm, then the diameter of the transverse reinforcement must be at least 8 mm.
- Overlapping knots are made in a run, which will increase the reliability of fasteners.
The calculation of the number of bars is done based on the grid spacing, the number of tiers, the length of the bars and the actual running meters at the construction site. For a visual representation of the optimal reinforcement of the foundation, it is desirable to draw up a plan and diagram. A specific calculation example for a tape base can be represented as follows:
- Section of foundation 0.4 × 1 m or 4000 cm2.
- The area to be reinforced is 4000 × 0, 001=4 cm2.
- According to the technological recommendations from the normative documentation, 8 rods with a diameter of 8 mm are obtained.
- For ease of placement, you can choose half of the bars with a tolerance of up to 12 mm.
Installation of rods in a monolithic foundation
This type of bearing base assumes that the loads will be distributed over the entire area. The optimal type of rods -with a corrugated surface with a diameter of 8-14 mm. At the first stage, the draft base is assembled with the formation of the lower level of the grid of rods. Squares with sides of 20-30 cm are created. Vertical racks are also made to reinforce the initial strapping belt. For such purposes, a larger diameter rod is used, and the step between the posts is maintained at a distance of up to 40 cm. It is important to consider that reinforcing the foundation slab will require more fastening consumables. Therefore, to simplify the connection operation, welding is often used. This fastening option is less laborious than strapping, but it can also be inferior in reliability - it depends on the type of welding used.
Installation of rods in the strip foundation
In this case, the formwork will be carried out linearly along the contours of the construction site. The foundation tapes are approximately 50 cm thick, so the mesh width can be a maximum of 40 cm. When laying, it is important to maintain 5 cm of space to the wall. To form the frame, lengths of the order of 40-60 cm are made. The vertical rods should be longer, which will allow, upon completion, to perform an additional upper trim without side rods. Also, the reinforcement of the strip foundation provides for the integration of full rods that capture the entire length of the box. But even in this case, up to 10 cm of free space should remain at the ends to the extreme walls. At the bottom of the formwork, plastic rod clamps are also installed, which will act as temporary load-bearing devices. Next, you can proceed tostrapping.
Knitting rods
Again, the wire connection can be replaced by welding, but burning through the metal as such will reduce the quality of the fastener. The main strapping is carried out at the corners of the wire joints in the cells of the structure. It is desirable to perform labor-intensive reinforcement of a monolithic foundation with a special knitting gun. If the amount of work is small, then the operations are performed with a knitting hook. This is a special device that allows you to manually make wire connections with a diameter of up to 1.4 mm.
The optimal length of the attachment pieces is 40 cm. They are first folded in half, and then twisted diagonally in a crosswise manner. The endings are hooked and rotated until a secure connection is created. If the strip foundation is being reinforced, then the so-called rigid foot should also be used as an addition. In such a system, a bend is formed at the end of the rod, capturing another hook from a perpendicular line. With the help of this fastener, in particular, laying is formed at the points of junction of the walls of the frame to each other.
Knitting with collars
An alternative fastening method, also used in bringing together and fixing critical parts of the frame that are under heavy loads. Two types of clamps can be used: L- and U-shaped. In the first case, one side of the element is attached to the frame wall, and the other side is attached to it, but perpendicularly. Grip length is calculated based on the diameterrod. U-shaped devices are used in the reinforcement of foundation slabs as a consumable for welding. Clamps are joined to two parallel rods, closing in the knot and one perpendicular line.
Common mistakes in reinforcement
Most often mistakes are made during settlement operations. Moreover, this applies to initially incorrect data on the structure of the foundation foundation in terms of interaction with the soil. For example, seismic activity can eventually deform a structure assembled using too thin rods. Under such conditions, it is most beneficial to reinforce the columnar foundation, on which the loads are placed pointwise, without affecting the tiled array, as is the case with a monolithic platform. A lot of mistakes are made when connecting parts of the frame and individual rods. When using the same wire, it is important to maintain the optimum tightening force so that the knot does not deform due to internal overload.
Conclusion
Today, the construction industry offers not so many fundamentally new reinforcement methods that can replace traditional technologies. Only innovative glass-composite rods are beginning to be widely used, but this option, due to the high price, does not always compete with metal. Experts still consider the tape configuration with wire strapping to be the best option for reinforcing the foundation of a private house. This is quite painstakingexecution is a way to strengthen the structure, but it is beneficial both in terms of financial costs and in terms of the quality of the result. Properly assembled foundation base with such binding of rods will provide an average building with a high degree of reliability and durability under natural loads.
