A complete collection of building reinforcement symbols.
Reinforcement is mainly divided into primary reinforcement, secondary reinforcement, tertiary reinforcement, etc. There are many ways to express steel bar symbols, which vary in different constructions. Next, let''''s take a look at the Encyclopedia of Building Reinforcement Symbols to provide a useful reference for annotating reinforcement.
How are the grades of steel bars divided? What are the types of steel bars?
Reinforcement type symbol.
The steel bars used in reinforced concrete structures include hot-rolled steel bars, waste heat treated steel bars, steel strands, cold-rolled ribbed steel bars, cold drawn steel bars, cold drawn steel wires, cold-rolled twisted steel bars, etc. Hot rolled steel bars are finished steel bars formed by hot rolling and natural cooling, which are divided into hot-rolled round bars and hot-rolled ribbed steel bars. Cold rolled ribbed steel bar is a crescent shaped steel bar formed by hot rolled wire rod through multiple passes of cold rolling reduction, one pass of rib compression, and elimination of internal stress, with two or three sides.
The causes of residual stresses in hot-rolled and cold-rolled steel sections are different, resulting in significant differences in their distribution on the cross-section. Cold rolled steel allows for local buckling of the cross-section, thereby fully utilizing the post buckling bearing capacity of the steel bars. However, local buckling of hot-rolled steel sections is not allowed. The free torsional stiffness of hot-rolled steel is higher than that of cold-rolled steel, therefore the torsional performance of hot-rolled steel is better than that of cold-rolled steel.
Grade and diameter symbols for hot-rolled steel bars.
The representation method of this steel bar symbol is mainly divided based on the shape, performance, and grade of the steel bar. It can be seen that the performance of steel bars is divided into many types and grades. Pay attention to these issues when purchasing steel bars.
Reinforcement marking.
In general, during the construction process, we still express the quantity and size of the required steel bars, as well as the diameter between the steel bars. The expression method is exactly the same as above, so as to improve it during the construction process.
A general reinforcement representation.
The above are symbols for general reinforcement. What are the commonly used component codes for reinforcing steel? Next, we will continue to take you through it.
The above figure shows some commonly used specifications for reinforced steel components, such as using B for slabs and WJ for roof trusses, which are easy to remember and widely used in construction engineering.
Next, Bian Xiao will introduce the specific classification knowledge of steel to everyone.
Common classification knowledge of steel bars.
There are many types of steel bars, which are usually classified based on their chemical composition, production process, rolling shape, supply form, diameter, and structural purpose:
（1） According to the rolling shape.
(1) Smooth steel bars: The first level steel bars (Q235 steel bars) are all rolled into smooth circular sections, supplied in the form of circular plates with a diameter not exceeding 10mm and a length of 6-12m.
(2) Ribbed steel bars: There are three types: spiral, herringbone, and crescent. Generally, second and third level steel bars are rolled into a zigzag shape, while fourth level steel bars are rolled into a spiral or crescent shape.
(3) Steel wire (including low-carbon steel wire and carbon steel wire) and steel strand.
(4) Cold rolled twisted steel bars: Cold rolled twisted steel bars.
(2) Divide by diameter.
Steel wire (diameter 3-5 millimeters), fine steel bar (diameter 6-10 millimeters), and coarse steel bar (diameter 22 millimeters or more).
(3) Based on mechanical properties.
First grade steel bars (235/370 grade); Grade II steel bars (335/510 grade); Grade III steel bars (370/570) and Grade IV steel bars (540/835).
（4） According to the production process.
Hot rolled, cold rolled, and cold drawn steel bars, as well as heat-treated steel bars made from grade four steel bars, have higher strength than the former. (5) It is divided into compressive reinforcement, tensile reinforcement, upright reinforcement, distributed reinforcement, hoop reinforcement, etc.