What is the rebar for the Foundation: types, calculation
The contents
As the basis of any modern concrete structures use specialized steel rebar, which you should not worry about interaction between the various elements of the base, so that they perfectly resist any tensile stresses. If you compare, the rebar for the Foundation, a calculation which was carried out really correctly, will serve as a reliable skeleton for the Foundation, it is only when using it you can say that the basis is really reliable, durable and absolutely safe.
What is a construction fittings? ↑
The rebar for the Foundation is high-strength material, which is made from smooth or ribbed profile. Valve rods are made of high strength steel, but in some cases they are also made from fiberglass. According to the manufacturers, fiberglass reinforcement provide a much higher strength compared to steel.
One of the most important indicators of rebar is considered to be its diameter, represented today in a wide range. Than the greater will be the diameter, the greater the requirements for strength characteristics. If this is the standard construction in this case is enough to use the valve, the diameter of which is 8 to 16 mm. For each individual the Foundation needed to choose individually rebar, that is for the same strip Foundation will need to use rods of the same diameter, while in the bored pile Foundation, they will be different.
The surface and its value ↑
As mentioned above, the rebar for the Foundation is equipped with a smooth or ribbed surface, however, many do not know what variant is more optimal. If we are talking about material that will provide high efficiency of resistance to tensile loads, it should be seen rebar is ribbed because it has high adhesion with concrete solution. Rods with a smooth surface in the majority of cases only be used as a constructive element of the skeleton, that is used to provide the orientation in space for ribbed rebar.
How is she fit? ↑
The simplest and most widely available technology is today considered welding multiple bars in a single frame. It is worth noting the fact that this technology is also extremely fast execution, but in those places where welding is carried out, the product starts to completely lose its strength. For this reason, this technology is far not the best solution, and should only be used in that case, if the situation is hopeless.
Another common technology is the binding of the valve which provides for the formation of the wire bonds at each intersection of the rods. It is quite a difficult job, but if used, then each connection will leave approximately five seconds. The holding of binding you need to implement before you will install the formwork for the Foundation.
What fittings to choose for strip Foundation? ↑
One of the features characteristic of the strip Foundation is that in this case, the upper and lower belt reinforcement. In this regard, the diameter of the rods will directly depend on what kind of load has a design on the Foundation, but in majority of cases it is about 9 to 14 mm. the greater the diameter of the used reinforcement, capitaline will be erected the building. Reinforcing belt is made up of two ribbed rods, which are connected with the help of jumpers and smooth rods. The diameter of the smooth rods should be 8 mm, and they should be placed in increments of approximately 500 mm, not only in horizontal but in vertical planes.
In the end, all the elements of the frame optionally covered with a layer of concrete, which is used for additional protection of the structure. Longitudinally oriented rods should be as close as possible to a horizontal surface, as a kind of beam which is extremely resistant to various strains. In order to set the vertical elements, should prepare a base, which should have a thickness of 30 mm. So you will be able to provide effective protection of materials against corrosion, which frequently occurs due to frequent exposure to moisture.
Creating a monolithic structure, it is not recommended to do the rods at the corners at right angles, as you will drive all your efforts. The placement of the bars should be lapped with the subsequent binding of brocolli.
If we are talking about bored piles, in this case, the armature for the Foundation includes ribbed bars with a diameter of about 10 mm. their Number in this case will depend on the diameter of the shape fill. In the majority of cases, the fill is an asbestos-cement pipe, the diameter of which is 200 mm In this case, it is enough to use 3-4 of the armature bar so that the bottom of them rested on the concrete pad prepared in advance.
What to use for slab Foundation? ↑
The base slab is characterized by its extremely high degree of reliability, but accordingly, it is the most expensive among all. Thus, the cost of reinforcement could take approximately 20% of the total cost of construction. For the erection of such bases, you can use rebar, whose diameter ranges from 9 to 15 mm, it should not be forgotten that the more complex are the conditions of construction, the greater the diameter of the rods should choose. It is recommended to put two belts, but so that eventually formed the cell.
What grade of rebar to choose? ↑
The rebar for the Foundation is used class A-I or A-III.
The first variant is characterized by a constant circular cross-section and smooth surface. In the majority of cases the use of such valves is carried out in those parts of the Foundation on which not is applied a large load, that is, where there is no strong zone of stretching. Such devices are used for forming a reinforcement cage, therefore it is called mounting. For example, if we are talking about reinforcement strip Foundation, these rods are used for vertical and for transverse reinforcement.
Construction reinforcement class A-III has a variable cross-section, that is, you’ll be ribbed. As mentioned above, due to the ribbed surface of this reinforcement is a much better contact with the concrete, resulting in its more relevant to use in those places in which there is increased tension. This armature will take the whole tensile load, therefore its thickness should be greater than the mounting.
If you want to build a small light house, the total weight will be approximately 50 tons, the frame for the Foundation of reinforcement may include rods, diameter not exceeding 10 mm, while the mounting surface may have a diameter of 6 mm. If built heavier house, in this case, the diameter should be 12 mm and more.
Valves of small diameter are actively sold not only in the bays, but in the form of separate bars. More of the same thick rebars for the Foundation in the majority of cases are sold exclusively in the form of bars.
Choose a wire binding method ↑
The number of tie wire for each bundle is approximately 0.3 meters, a total of ligaments in each joint 4. The diameter of the wire, which is used for a bunch of rods located in the corners of the frame, is about 1 mm. through production of a reinforcing frame, it is customary to use the technology of binding with steel wire to ensure maximum durability. It is not recommended to use welding if you don’t want to be able to detect corrosion at the enterprises of rods.
Professionals often use a specialized gun for mating fittings, which allows to significantly reduce labor costs, but the cost of this tool for many is quite high, so it is not always possible to use it in laying the Foundation with his own hands.
The diameter and number of valves used is directly dependent on how massive the structure is, what type of soil is present at the construction site and what specific type of Foundation is laid. Calculating rebar for a Foundation should be carried out in the design process of the entire building, and only the most exact observance of the recommendations specified in the design documentation, as well as competent observance of technology of construction will ensure long service life of the Foundation, which is more than 150 years.
For more information on how to fit the fittings you can see in the video below: