Rebar

By its application, rebar for reinforced concrete structures can be classified as:

• main reinforcing bars that reduce external loads and tension caused by the block’s weight;

• distribution bars that evenly distribute the loads between the main rods and ensure their joint work; 

• mounting bars that are used for framework assembly and ensure precise positioning of main reinforcing bars and clamps;

Depending on certain features and properties, rebar can be of the following type:

• by manufacturing technology: hot-rolled and cold-rolled rebar;

• by shape of the surface: plain and deformed rebar;

• by production method: prestressed and non-stressed rebar;

• by rod diameter and weight: lightweight and heavy rebar;

• by service characteristics: welded and non-welded, as well as resistant and non-resistant to corrosion cracking from stress.

Rebar standards in Ukraine and CIS countries

The main standard for rebar in Ukraine is DSTU 3760:2019. In the CIS countries, reinforcing bar is produced according to GOST 5781-82 and GOST 10884-94. The main strength classes, according to CIS standards, are A240C (plain rebar), as well as A500C and A400 (deformed rebar).

European standards

In the EU, rebar standards vary from country to country. Different strength classifications are also used: B500B, B500C, Gr 460B, PC 52, etc. One of the most common European standards is DIN 488 (Germany). This standard is used for sales of rebar with diameter from 6mm to 40 mm, with length ranging from 6 m to 18m, and nominal weight ranging from 0.222 kg per meter to 9.86 kg per meter.

US standards

The main US standards for rebar are ASTM A615/А615М. The Canadian standard is CSA G30.18-09.

Rebar production

Rebar is produced from carbon and low-alloyed steel grades by either hot rolling orcold rolling.

In the first case, the production of rebar with a diameter of 6-40 mm is based on heating a square billet in the furnace and gradually changing its shape by rolling it sequentially in the mill stands with grooved rolls. After rolling, the products are cut to length, cooled, and subject to quality tests before packing and shipping.

Also, hot-rolled reinforcing bars can be manufactured in coils, which are then cut to length on the straightening and cutting machines. Coiled rebar is very effective when used in various armour components, welded pylons, and other complex structural elements.

When producing cold-formed rebar, the feedstock, i.e. round hot-rolled steel, is put between the rotating plain or grooved rolls of the rolling mill. Thus, plain and ribbed, cold-rolled rebars with a diameter of 4-12 mm are made.