Rebar is undoubtedly one of the most important materials in human life. This valuable steel product is the main foundation of today’s structures, and without this metal section, it would have been impossible to advance construction as we see it today.
The standard of rebar is undoubtedly one of the important factors that designers of large and small structures consider. The mechanical properties of this product change according to its manufacturing standard and this issue makes its application in different parts different. In this article, we will examine the types of standard rebar collectors in the world and in Iran, and we will explain the specifications of each.
When producing a product, each factory tries to produce the best product according to the market and the presence of competitors, and for this purpose, two factors are considered :
- High quality product
- Low cost
Every product to have these two conditions will need a production process with the latest technology and compliance with standard principles. Technology in the world today is changing momentarily; But the standards are not like this and usually change every one or two years. But sometimes it is possible that the standard does not change over the years.
International rebar standards
We face several different standards for rebar production. These standards have been developed by international organizations, the most reputable of which are :
- ATSM American Materials and Testing Association to which the ACI Regulations (318-14) belong.
- JIS Japan, which has announced the standard (JIS G3112) for rebars used in concrete.
- German DIN, the standard (DIN 488) for steel used in reinforced concrete.
- ISO, the International Organization for Standardization (ISO 6935) for steel.
British, Canadian, American and Australian standards are also referenced by rebar companies.
Rebar standard in Iran
In Iran, Zobahan Company, as a pioneer in the steel industry, has used the Russian standard for the production of rebar. But other standards are also used in the country in the production process :
- Russian standard
- ISIRI 3132 standard
- DIN standard
What criteria are considered in determining the standard of rebar?
The first review of the rebar standard deals with its physical characteristics. Manufacturers each produce their own rebar with a different nominal diameter and length, which is based on the length of the rebar and the diameter of the rebar weight table.
This table will be different based on different standards in companies. In the standards, the rebar weight tables will be based on the definitions based on which the standard definitions are formed. One of the applications of these tables is to have the packing weight of rebars after production, which is known as rebar size bundle.
Russian standard rebar
In the Russian standard, rebars are divided into four categories: rebars A1, A2, A3, A4
Rebar A1
The appearance of this rebar is smooth and has no tread on its body. In industry, this type is called soft rebar. This rebar is used in heat treatment because it does not have a tread. In this type, since very little carbon is used in the chemical composition, it can be used in bending and re-bending. We also have up to 25% deformation. In the consumer market, we can see A1 rebars with a length of six to 12 meters, which is in the family of ductile rebars.
Rebar A2
In this rebar, there is a tread on the body that these treads are uniform along the body and all in the same direction. The term of this rebar is called semi-brittle. The uses of this rebar are in construction affairs, the main use of which is in the construction work. This type of rebar is recommended not to be used in bending and welding. Also the deformation in it is 19%. This type of rebar is called a helical ribbed rebar.
Rebar A3
In terms of stiffness, this rebar is considered semi-rigid, which is not at all suitable for welding purposes. The appearance of this type of rebar, the ridges in the direction of length is in the form of a groove, which is known as a ribbed ribbed rebar. The deformation of this rebar is less than the previous two rebars and 14% and also more than other rebars can be found in the market.
Rebar A4
The tread shape of this rebar is similar to the tread of A3 rebar; The difference is that in this rebar, the beams are placed in opposite directions along the rebar. This type is classified into very hard categories and is used in structural work. This type of rebar is called dead rib rebar. Its price is more expensive than other rebars. The price of rebars varies depending on the quality and type of steel used.
Rebar production methods
Hot rolling : The method of producing the product by rolling is one of the most practical and common types of production that uses the deformation method. In hot rolling, we first bring the furnace temperature to 1100 degrees; This temperature is the melting point of the ingots to produce the rebar. The ingots are melted at the desired temperature and sent to the rafting stage.
Cold rolling : The cold rolling process is the same as hot rolling, except that the product will cool to room temperature. In cold rolling we will see a decrease in the diameter and thickness of the rebar.
Microalloy : The amount of rebar currently produced worldwide is estimated at 400 million tons per year. Rising global demand Due to increased infrastructure production, this level of production is constantly anticipated. Currently, for rebar, price is the only fact that is considered when buying for large projects. This “pricing only” mentality should not be turned into a commodity that quality Does not have to. Of course, this important point means that “pricing” should not be seen only in rebar, but should be considered in all metal projects. Observing hardware price charts can help you with this.
In the microalloying method, to increase the strength of the rebar, titanium, vanadium and rubidium alloys are added to the rebar in the production process. This type of addition of alloys increases the level of uniformity of the rebar and thus increases the tensile strength of the rebar. Therefore, it is better to use this type of rebar in earthquake-prone areas.
Thermax technology : In this method, the temperature first reaches 950 to 1000 degrees in hot rolling. In the next step, the hot rolling of the special system is cooled by the water of the outer surface. Because the ingot used in this method is of lower quality, this cooling will change the fragility of the outer surface. In the next step, the rebar comes out of the cooling section and cools at room temperature. This cooling causes an inverse temperature transfer from the inner hot part to the outer cold part, in which case the fragility of the outer surface gives way to toughness.
These methods will have different mechanical standards. Various tests must be performed to find the standard for these resistors. Each standard has its own test conditions. Because standard 3132 is currently accepted in Iran and it has seen light rolling, we will recount it.
Tensile test : To determine the amount of tension, we must stretch five or 10 times the nominal diameter of the rebar. Tremax specimens should be tested without any turning.
Bending test : The subject should be tested around its bending axis from 160 to 180 degrees proportional to its diameter.
Signs and abbreviations on the rebar
To identify rebars made in the ASTM standard process, codes are installed on the body of the rebar that must be read as follows :
The first line that is written on the body of the rebar is the letters that mean the type of factory production that is the contract.
The second line represents a number that indicates the nominal diameter of the rebar.
The third line shows the type of steel used.
- S: Carbon-steel (A615)
- W: Low-alloy steel (A706)
- R: Rail-steel (A996)
- I: Axle-steel (A995)
The fourth line shows the grid number.
- Number 40 grade 40
- Number 60 Grade 60
- Number 75 grade 75
- Number 4 grade 420 and also grade 60
- Grade 5 Grade 520 Also Grade 75
The conditions for packing and sending the production rebar to the customer are in accordance with certain rules and regulations. These rules in standard 3132 are as follows :
packing
Except for 500 or 520 tread rebars up to a nominal diameter of 14, they are packed in bundles of equal length or coil in the form of branches of equal length and above the diameter of 14 in the form of branches. But in the 500 or 520 tread, with each diameter, only branches of equal length are packed that will not have a coil shape.
ID
The ID of the ribbed and plain rebar will be as follows :
- National standard number after obtaining a production license
- Nominal diameter
- Standard rebar characteristic mark
- Production process code
Marking on the package
Each rebar package must have a special card or license plate on which the production specifications are written and displayed to the buyer, which are :
- Trademark of rebar manufacturer
- National standard number
- Rebar characteristic mark
- Nominal diameter
- Melting code
- Rebar length
- Name of country of manufacture
- Weight in kilograms
Ribbed rebar
Rebar is a type of steel rod that is made in different sizes and is used for concreting. In most human structures, concrete is built for strength. Although concrete has a high resistance to compressive forces and requires extraordinary compressive strength to crush this material, it also has a weakness. Concrete does not have much resistance to tensile and rotational forces, this is where the rebar enters the field and protects the structures against tensile forces. In fact, this steel product is used to strengthen concrete.
It is a ribbed rebar, reinforcement or steel iron that is used in concrete structures in order to provide the desired tensile strength in the structure and to compensate for the low tensile strength of concrete. This type of steel that is used in reinforced concrete structures to provide the above conditions is called rebar.
Rebars are generally produced in various types. These products are known in four groups A1 to A4. Group A1 rebars are not ribbed and are referred to as simple rebars, which are usually suitable for welding and bending. Ribbed rebar is one of the most important materials required in the construction industry. Figure 1 graphically shows the use of ribbed rebar in reinforcing concrete. The price of ribbed rebar plays an important role in the cost of construction projects. The difference between each type of ribbed rebar depends on the size of the ridges and their appearance. Ribbed rebar is divided into 3 categories based on appearance: composite, spindle and uniform.
Types of ribbed rebars
- Ribbed rebar with spiral or uniform tread
- Ribbed rebar with spindle-shaped tread
- Ribbed rebar with composite tread
Simple rebar
Rebar is one of the solid steel sections with a circular cross section that has many uses in industry, especially construction.
In general, rebars are divided into two categories: branches and coils, and rebar that does not have a tread is commonly called simple rebars. Steel rebars are sections that are either used to strengthen concrete against tensile forces or stresses, or in Building stones (building facades) are used. The word Rebar, which refers to the types of rebars, is actually made up of a combination of the words Reinforcement meaning reinforcement and Bar meaning rod.
Thermal rebar
There are different types of rebars that are selected depending on the intended use. One of the types of rebars is thermal rebar which is more used than ordinary rebar. The use of thermal rebar ensures greater strength of concrete and prevents the occurrence of possible consequences and hazards.
After concreting the roof, drop and heat rebars are used to prevent the concrete from cracking. In fact, the main function of these rebars is to prevent stresses due to shrinkage and heat of concrete, and for this reason they are called thermal reinforcement. Thermal reinforcement prevents the expansion and contraction of concrete and the creation of cracks, thus reducing the width of the cracks.
Rebar specific weight table
In the rebar weight table, the weight of each 12-meter rebar branch is described in detail. The rebar weight table describes in detail everything you need to know about the weight of plain, ribbed rebar and the weight of ribbed coil.
| Row | Rebar size (mm) | Rebar weight (kg) |
|---|---|---|
| 1 | Rebar 8 | 5 |
| 2 | Rebar 10 | 8 |
| 3 | Rebar 12 | 11 |
| 4 | Rebar 14 | 15 |
| 5 | Rebar 16 | 19 |
| 6 | Rebar 18 | 24 |
| 7 | Rebar 20 | 30 |
| 8 | Rebar 22 | 36 |
| 9 | Rebar 25 | 47 |
| 10 | Rebar 28 | 58 |
| 11 | Rebar 36 | 76 |
| 12 | Rebar 36 | 96 |
Rebar weight
The weight of the rebar depends on factors such as the size of the rebar and its length. The weight of this metal is calculated according to the above formula. Usually, the size and diameter of these rebars are produced and supplied according to the standard used in Iran under the name of religion. Rebar is a type of steel product that has a very small diameter to length ratio and is divided into two types, ribbed and simple.
The usual diameter of the rebar is 6 to 32 mm and the common length of these rebars will be about 12 meters, which for smaller diameters, such as less than 10 mm, coils are produced. Among the standards available in Iran, we can name the standard or grades AII and AIII Vera. All kinds of rebars are sold online in Kian Petroleum company.
Whereas integration and coordination in responding to the needs of domestic and international applicants is one of the important principles of Kian Group in order to achieve the satisfaction of applicants; You can send us a request to purchase your desired products through the following communication channels :
Iran Office : 00983535227500 – 00989120525658
Turkey Office : 00905387445869
email : Info@kiangroup.net